Linux Router with VPN on a Raspberry Pi: Difference between revisions

From Alpine Linux
(Mention dhcpcd)
(39 intermediate revisions by 5 users not shown)
Line 1: Line 1:
[[Category:Networking]]
{{TOC right}}
 
= Rationale =
= Rationale =


Line 8: Line 9:
For wireless, a separate access point was purchased ([http://wiki.openwrt.org/toh/ubiquiti/unifi Ubiquiti UniFi AP]) because it contains a Atheros AR9287 which is supported by [https://wireless.wiki.kernel.org/en/users/drivers/ath9k ath9k].
For wireless, a separate access point was purchased ([http://wiki.openwrt.org/toh/ubiquiti/unifi Ubiquiti UniFi AP]) because it contains a Atheros AR9287 which is supported by [https://wireless.wiki.kernel.org/en/users/drivers/ath9k ath9k].


I only chose a Raspberry Pi due to the fact it was inexpensive. My WAN link is pathetic so I was not concerned with getting high PPS ([https://en.wikipedia.org/wiki/Throughput Packets Per Second]). You could choose to use an old x86/amd64 system instead. This may be a more attractive option if you want to route high speeds. If you want to route speeds above 100 Mbit/s you'll want to make use of hardware encryption like AES-NI.
I only chose a Raspberry Pi due to the fact it was inexpensive. My WAN link is pathetic so I was not concerned with getting high PPS ([https://en.wikipedia.org/wiki/Throughput Packets Per Second]). You could choose to use an old x86/amd64 system instead. If I had better internet I'd probably go with an offering from [https://soekris.com Soekris] such as the [https://soekris.com/products/net6501-1.html net6501] as it would have a much lower power consumption than a generic x86_64 desktop processor.
 
If you want to route speeds above 100 Mbit/s you'll want to make use of hardware encryption like [https://en.wikipedia.org/wiki/AES_instruction_set AES-NI]. The [https://soekris.com Soekris] offerings have the option of an additional hardware encryption module ([https://soekris.com/products/vpn-1411.html vpn1411]). Another option is to use a [https://en.wikipedia.org/wiki/Mini-ITX Mini ITX motherboard], with a managed switch. I chose the [https://www.ubnt.com/edgemax/edgeswitch Ubiquiti ES-16-150W].


If you wish to use IPv6 you should consider looking at [[Linux Router with VPN on a Raspberry Pi (IPv6)]] as the implementation does differ slightly to this tutorial.


The network in this tutorial looks like this:  
The network in this tutorial looks like this:  
Line 24: Line 28:


The modem I am using is a [http://www.cisco.com/c/en/us/products/routers/877-integrated-services-router-isr/index.html Cisco 877 Integrated Services Router]. It has no web interface and is controlled over SSH. More information can be found [[Configuring a Cisco 877 in full bridge mode]].
The modem I am using is a [http://www.cisco.com/c/en/us/products/routers/877-integrated-services-router-isr/index.html Cisco 877 Integrated Services Router]. It has no web interface and is controlled over SSH. More information can be found [[Configuring a Cisco 877 in full bridge mode]].
= Configuring PPP =
Next up we need to configure our router to be able to dial a PPP connection with our modem.
{{cmd|apk add ppp-pppoe}}
Check that the interface between your router and modem is eth1, or change it. Enter your credentials at the bottom of the file or use /etc/ppp/chap-secrets
== /etc/ppp/peers/yourISP ==
<pre>#
# PPP Configuration file
#
nolog
# Try to get the IP address from the ISP
noipdefault
# Try to get the name server addresses from the ISP
usepeerdns
# Use this connection as the default route.
defaultroute
defaultroute-metric 300
# detatch after ppp0 interface is created
updetach
# Replace previous default route
# This requires a special patch to ppp
# https://sources.debian.net/src/ppp/2.4.7-1%2B1~exp1/debian/patches/cifdefroute.dif/
# replacedefaultroute
# rp-pppoe plug-in makes PPPoE connection so rp-pppoe package is not needed
# Possibly, you may need to change interface according your configuration
plugin rp-pppoe.so eth1
# Uncomment if you need on-demand connection
#demand
# Disconnect after 300 seconds (5 minutes) of idle time.
#idle 300
# Hide password from log entries
hide-password
# Send echo requests
lcp-echo-interval 20
lcp-echo-failure 3
# Do not authenticate ISP peer
noauth
# Control connection consistency
persist
maxfail 0
# Control MTU size if your ISP does not force it
#mtu 1492
user "username@yourISP.tld"
# Compression
bsdcomp 15
deflate 15</pre>
== /etc/ppp/chap-secrets ==
Enter in your login credentials
<pre># Secrets for authentication using CHAP
# client server secret IP addresses
"username@yourISP.tld"         * "<your password>"</pre>
== /etc/modules ==
Update modules to include pppoe:
<pre>pppoe</pre>


= Network =
= Network =
Line 137: Line 65:
   address 192.168.1.1
   address 192.168.1.1
   netmask 255.255.255.0
   netmask 255.255.255.0
   broadcast 192.168.1.255
   broadcast 192.168.1.255</pre>


# External Interface - facing Modem
 
=== PPP ===
Next up we need to configure our router to be able to dial a PPP connection with our modem.
 
If your ISP uses [https://en.wikipedia.org/wiki/Point-to-Point_Protocol PPP] you may need to configure it. See [[PPP]].
 
You will want to make sure you set your WAN interface, in this example we used eth1.
 
<pre># External Interface - facing Modem
allow-hotplug eth1
allow-hotplug eth1
auto eth1
auto eth1
Line 155: Line 91:
   provider yourISP</pre>
   provider yourISP</pre>


== Basic IPtables firewall with routing ==
=== IPoE ===
This demonstrates how to set up basic routing with a permissive outgoing firewall. Incoming packets are blocked. The rest is commented in the rule set.
Alternatively it's quite common for ISPs to use [https://en.wikipedia.org/wiki/IPoE IPoE]. IPoE is much simpler and only runs DHCP on the external interface. It should look something like:
 
<pre># External interface to ISP
allow-hotplug eth1
auto eth1
iface eth1 inet dhcp


First install iptables:
iface eth1 inet static
    address 192.168.0.2
    netmask 255.255.255.252
    broadcast 192.168.0.3


{{cmd|apk add iptables ip6tables}}
iface eth1 inet6 manual</pre>


<pre>#########################################################################
==== DHCP from ISP ====
# Basic iptables IPv4 routing rule set
#
# 192.168.1.0/24 routed directly to PPP0 via NAT
#
#########################################################################


#
Above we set DHCP and we set a static IP. The purpose of this is so we can still forward packets through to the modem to be able to access the web interface or ssh.
# Mangle Table
# We leave this empty for the moment.
#
*mangle
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
COMMIT


#
We do still need DHCP to get an IP address form our ISP though. I like to use dhcpcd instead of udhcp (the default in Alpine Linux), because it allows for [https://en.wikipedia.org/wiki/Prefix_delegation Prefix Delegation], which is used in IPv6 networks.
# Filter Table
# This is where we decide to ACCEPT, DROP or REJECT things
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
*filter


# Create rule chain per input interface for forwarding packets
My /etc/dhcpcd.conf looks like this:
:FWD_ETH0 - [0:0]
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]


# Create rule chain per input interface for input packets (for host itself)
<pre># Enable extra debugging
:IN_ETH0 - [0:0]
# debug
:IN_ETH1 - [0:0]
# logfile /var/log/dhcpcd.log
:IN_PPP0 - [0:0]


# Create a log drop chain
# Allow users of this group to interact with dhcpcd via the control
:LOG_DROP - [0:0]
# socket.
#controlgroup wheel


# Pass input packet to corresponding rule chain
# Inform the DHCP server of our hostname for DDNS.
-A INPUT -i lo -j ACCEPT
hostname gateway
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0


# Pass forwarded packet to corresponding rule chain
# Use the hardware address of the interface for the Client ID.
-A FORWARD -i eth0 -j FWD_ETH0
# clientid
-A FORWARD -i eth1 -j FWD_ETH1
# or
-A FORWARD -i ppp0 -j FWD_PPP0
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as
# per RFC4361. Some non-RFC compliant DHCP servers do not reply with
# this set. In this case, comment out duid and enable clientid above.
duid


# Forward LAN traffic out
# Persist interface configuration when dhcpcd exits.
-A FWD_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
persistent


# Forward SSH packets from network to modem
# Rapid commit support.
-A FWD_ETH1 -s 192.168.0.0/30 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Safe to enable by default because it requires the equivalent option
# set on the server to actually work.
option rapid_commit


# Forward HTTP to modem's webserver
# A list of options to request from the DHCP server.
-A FWD_ETH1 -s 192.168.0.0/30 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes


# Forward traffic to ISP
# Most distributions have NTP support.
-A FWD_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
option ntp_servers


# SSH to Router
# Respect the network MTU.
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Some interface drivers reset when changing the MTU so disabled by
# default.
#option interface_mtu 1586


# DNS to Router
# A ServerID is required by RFC2131.
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
require dhcp_server_identifier


# FreeRadius Client (eg a UniFi AP)
# Generate Stable Private IPv6 Addresses instead of hardware based
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# ones
slaac private


# NTP to Router
# A hook script is provided to lookup the hostname if not set by the
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# DHCP server, but it should not be run by default.
nohook lookup-hostname


# Accept traffic
# Disable solicitations on all interfaces
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
noipv6rs


# SSH To Modem from Router
# Wait for IP before forking to background
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
waitip 6


# HTTP to modem
# Don't touch DNS
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
nohook resolv.conf


# Accept incoming tracked PPP0 connection
allowinterfaces eth1 eth0.2
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
# Use the interface connected to WAN
COMMIT
interface eth1
    waitip 4
    noipv4ll
    ipv6rs # enable routing solicitation get the default IPv6 route
    iaid 1
    ia_pd 1/::/56 eth0.2/2/64
    timeout 30
 
interface eth0.2
    ipv6only</pre>
 
== Basic IPtables firewall with routing ==
This demonstrates how to set up basic routing with a permissive outgoing firewall. Incoming packets are blocked. The rest is commented in the rule set.
 
First install iptables:
 
{{cmd|apk add iptables ip6tables}}
 
<pre>#########################################################################
# Basic iptables IPv4 routing rule set
#
# 192.168.1.0/24 routed directly to PPP0 via NAT
#
#########################################################################


#
#
# NAT Table
# Mangle Table
# This is where translation of packets happens and "forwarding" of ports
# We leave this empty for the moment.
# to specific hosts.
#
#
*nat
*mangle
:PREROUTING ACCEPT [0:0]
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
COMMIT


# Port forwarding for Bittorrent
#
-A PREROUTING -i ppp0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.1.20
# Filter Table
-A PREROUTING -i ppp0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.1.20
# This is where we decide to ACCEPT, DROP or REJECT things
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
*filter


# Allows routing to our modem subnet so we can access the web interface or SSH
# Create rule chain per input interface for forwarding packets
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 22 -j MASQUERADE
:FWD_ETH0 - [0:0]
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]


# Allows hosts of the network to use the PPP tunnel
# Create rule chain per input interface for input packets (for host itself)
-A POSTROUTING -s 192.168.1.0/24 -o ppp0 -j MASQUERADE
:IN_ETH0 - [0:0]
COMMIT</pre>
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]


I'd also highly suggest reading these resources if you are new to iptables:  
# Create a log drop chain
:LOG_DROP - [0:0]


* [https://www.frozentux.net/category/linux/iptables Frozen Tux Iptables-tutorial]
# Pass input packet to corresponding rule chain
* [http://inai.de/links/iptables/ Words of wisdom for #netfilter]
-A INPUT -i lo -j ACCEPT
* [http://sfvlug.editthis.info/wiki/Things_You_Should_Know_About_Netfilter Things You Should Know About Netfilter]
-A INPUT -i eth0 -j IN_ETH0
* [http://inai.de/documents/Perfect_Ruleset.pdf Towards the perfect ruleset]
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0


== /etc/sysctl.conf ==
# Pass forwarded packet to corresponding rule chain
These sysctl settings harden a few things and were mostly borrowed from the [https://wiki.archlinux.org/index.php/Sysctl#TCP.2FIP_stack_hardening ArchLinux wiki]. This particular config was based on [https://www.lisenet.com/2015/kernel-sysctl-configuration-for-linux Kernel Sysctl Configuration for Linux from lisenet.]
-A FORWARD -i eth0 -j FWD_ETH0
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0


<pre># https://www.lisenet.com/2015/kernel-sysctl-configuration-for-linux/
# Forward LAN traffic out
-A FWD_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Kernel sysctl configuration file for Linux
# Forward SSH packets from network to modem
#
-A FWD_ETH1 -s 192.168.0.0/30 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# By: www.lisenet.com
#
# Tested on a Red Hat server with physical memory of 2GB
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.
#
# References
# https://www.suse.com/documentation/sles-12/book_hardening/data/sec_sec_prot_general_kernel.html
# https://wiki.archlinux.org/index.php/Sysctl
# https://rtcamp.com/tutorials/linux/sysctl-conf/
# http://seriousbirder.com/blogs/centos-6-setting-shmmax-and-shmall-kernel-paramaters/
# http://kaivanov.blogspot.co.uk/2010/09/linux-tcp-tuning.html


# Any process which has changed privilege levels
# Forward HTTP to modem's webserver
# or is execute only will not be dumped (default)
-A FWD_ETH1 -s 192.168.0.0/30 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
fs.suid_dumpable = 0


# File handle limit
# Forward traffic to ISP
fs.file-max = 6577347
-A FWD_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT


########################################
# SSH to Router
###          Memory Tuning          ###
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
########################################


# Use swap file when RAM usage is around 40 percent
# DNS to Router
vm.swappiness = 60
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Controls the maximum number of shared memory segments, in pages (not bytes)
# FreeRadius Client (eg a UniFi AP)
# It is almost always 4K which is the recommended size
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# To be safe, run the following command:
# getconf PAGE_SIZE => 4096
# Allocating 1GB below (1*1024*1024*1024/4096=262144)
kernel.shmall = 262144


# Control the maximum size of a single shared memory segment, in bytes
# NTP to Router
# Setting to half (1GB) of our physical memory
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
kernel.shmmax = 1073741824


########################################
# Accept traffic
###        Kernel Hardening        ###
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
########################################


# Reboot a system after 10 seconds of kernel panic
# SSH To Modem from Router
kernel.panic = 10
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Controls the System Request debugging functionality of the kernel
# HTTP to modem
kernel.sysrq = 0
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Controls whether core dumps will append the PID to the core filename.
# Accept incoming tracked PPP0 connection
# Useful for debugging multi-threaded applications.
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
kernel.core_uses_pid = 1
COMMIT


# Restricting access to kernel logs
#
kernel.dmesg_restrict = 1
# NAT Table
# This is where translation of packets happens and "forwarding" of ports
# to specific hosts.
#
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]


# If you're compiling your own kernel, then
# Port forwarding for Bittorrent
# this can help mitigating local root exploits
-A PREROUTING -i ppp0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.1.20
kernel.kptr_restrict = 1
-A PREROUTING -i ppp0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.1.20


# Controls the default maxmimum size of a mesage queue
# Allows routing to our modem subnet so we can access the web interface or SSH
# kernel.msgmnb = 65536
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 22 -j MASQUERADE
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE


# Controls the maximum size of a message, in bytes
# Allows hosts of the network to use the PPP tunnel
# kernel.msgmax = 65536
-A POSTROUTING -s 192.168.1.0/24 -o ppp0 -j MASQUERADE
COMMIT</pre>


# Enable ExecShield protection
I'd also highly suggest reading these resources if you are new to iptables:
# kernel.exec-shield = 1  ## Disabled, not available with this kernel


# Enable by default, except if the application bits are set to "disable"
* [https://www.frozentux.net/category/linux/iptables Frozen Tux Iptables-tutorial]
kernel.randomize_va_space = 2
* [http://inai.de/links/iptables/ Words of wisdom for #netfilter]
 
* [http://sfvlug.editthis.info/wiki/Things_You_Should_Know_About_Netfilter Things You Should Know About Netfilter]
# Default
* [http://inai.de/documents/Perfect_Ruleset.pdf Towards the perfect ruleset]
kernel.pid_max = 32768
 
# Increase the length of the processor input queue
net.core.netdev_max_backlog = 5000
 
# The maximum number of "backlogged sockets". Default
net.core.somaxconn = 128
 
# Disable netfilter on bridges.
#net.bridge.bridge-nf-call-ip6tables = 0
#net.bridge.bridge-nf-call-iptables = 0
#net.bridge.bridge-nf-call-arptables = 0


########################################
== /etc/sysctl.d/local.conf ==
###      TCP/IP Stack Hardening      ###
<pre># Controls IP packet forwarding
########################################
 
# Controls IP packet forwarding
net.ipv4.ip_forward = 1
net.ipv4.ip_forward = 1


# Disable fast recycling of TIME_WAIT sockets
# Needed to use fwmark, only required if you want to set up the VPN subnet later in this article
net.ipv4.tcp_tw_recycle = 0
 
# Do not allow reuse of sockets in TIME_WAIT state for new connections
net.ipv4.tcp_tw_reuse = 0
 
# Help prevent against SYN flood attacks
net.ipv4.tcp_syncookies = 1
 
# If set to 0, protect against wrapping sequence numbers
# Turning off timestamps may do more harm than good
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_sack = 1
 
# Enable windows scaling
net.ipv4.tcp_window_scaling = 1
# Maximum receive and send window size 16MB
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
# Increase the read-buffer and write-buffer space allocatable
# Autotuning TCP buffer limit 16MB
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
 
# Do not accept source routing
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0
 
# Disable redirects, not a router
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.secure_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.default.secure_redirects = 0
 
# Enable source validation by reversed path
# Protects from attackers that are using ip spoofing methods to do harm
net.ipv4.conf.all.rp_filter = 2
net.ipv4.conf.all.rp_filter = 2
net.ipv4.conf.default.rp_filter = 2
# Log packets with impossible addresses to kernel log
net.ipv4.conf.all.log_martians = 0      # Disabled to avoid spam
net.ipv4.conf.default.log_martians = 0  # Disabled to avoid spam
# Ignore all ECHO broadcast requests
# Prevent being part of smurf attacks
net.ipv4.icmp_echo_ignore_broadcasts = 1
# Ignore bogus ICMP errors
net.ipv4.icmp_ignore_bogus_error_responses = 1
# net.ipv4.icmp_ignore_bogus_error_messages = 1 ## Disabled, not available with this kernel
# Allowed local port range
net.ipv4.ip_local_port_range = 9000 65535
# The minimum time sockets will stay in TIME_WAIT state
net.ipv4.tcp_fin_timeout = 60
# protect against tcp time-wait assassination hazards
# drop RST packets for sockets in the time-wait state
# (not widely supported outside of linux, but conforms to RFC)
net.ipv4.tcp_rfc1337 = 1
########################################
###              IPv6                ###
########################################


# Disable IPv6
# Disable IPv6
Line 455: Line 324:
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1</pre>
net.ipv6.conf.default.disable_ipv6 = 1</pre>
Note IPv6 is disabled here if you want that see the other tutorial [[Linux Router with VPN on a Raspberry Pi (IPv6)]]. You may also wish to look at [https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt ip-sysctl.txt] to read about the other keys.


= DHCP =
= DHCP =
Line 556: Line 427:


Make sure to add this to the default run level once configured:
Make sure to add this to the default run level once configured:
{{cmd|rc-update add dhcp default}}
{{cmd|rc-update add dhcpd default}}


= Synchronizing the clock =
= Synchronizing the clock =


You can choose to use BusyBox's ntpd or you can choose a more fully fledged option like [http://www.openntpd.org OpenNTPD]
You can choose to use BusyBox's ntpd or you can choose a more fully fledged option like [http://www.openntpd.org OpenNTPD] or [https://chrony.tuxfamily.org Chrony]


== Busybox /etc/conf.d/ntpd ==
== Busybox /etc/conf.d/ntpd ==
Line 572: Line 443:


Or if you prefer to synchronize with multiple servers...
Or if you prefer to synchronize with multiple servers...
== Chrony /etc/chrony.conf ==
{{cmd|apk add chrony}}
<pre>logdir /var/log/chrony
log measurements statistics tracking
allow 192.168.0.0/30
allow 192.168.1.0/24
allow 192.168.2.0/24
allow 192.168.3.0/24
allow 192.168.4.0/24
broadcast 30 192.168.0.3
broadcast 30 192.168.1.255
broadcast 30 192.168.2.255
broadcast 30 192.168.3.255
broadcast 30 192.168.4.255
server 0.pool.ntp.org iburst
server 1.pool.ntp.org iburst
server 2.pool.ntp.org iburst
server 3.pool.ntp.org iburst
initstepslew 10 pool.ntp.org
driftfile /var/lib/chrony/chrony.drift
hwclockfile /etc/adjtime
rtcdevice /dev/rtc0
rtcsync</pre>


== OpenNTPD /etc/ntpd.conf ==
== OpenNTPD /etc/ntpd.conf ==
Line 611: Line 510:


= Unbound DNS forwarder with dnscrypt =
= Unbound DNS forwarder with dnscrypt =
We want to be able to do our lookups using [http://dnscrypt.org dnscrypt] without installing dnscrypt on every client on the network. Therefore the router will also run a DNS forwarder and request unknown domains over dnscrypt for our clients.
We want to be able to do our lookups using [https://dnscrypt.info/ dnscrypt] without installing DNSCrypt on every client on the network. DNSCrypt can use it's [https://dnscrypt.info/protocol own protocol] or [https://en.wikipedia.org/wiki/DNS_over_HTTPS DNS over HTTPS].
 
The router will also run a DNS forwarder and request unknown domains over DNSCrypt for our clients. Borrowed from the ArchLinux wiki article on [https://wiki.archlinux.org/index.php/dnscrypt-proxy dnscrypt-proxy].


== Unbound ==
== Unbound ==
Line 617: Line 518:


=== /etc/unbound/unbound.conf ===
=== /etc/unbound/unbound.conf ===
<pre># unbound.conf(5) man page.
<pre>server:
#
    # Use this to include other text into the file.
# See /usr/share/doc/unbound/examples/unbound.conf for a commented
    include: "/etc/unbound/filter.conf"
# reference config file.


server:
     # verbosity number, 0 is least verbose. 1 is default.
     # The following line will configure unbound to perform cryptographic
    verbosity: 1
    # DNSSEC validation using the root trust anchor.
    # auto-trust-anchor-file: "/var/lib/unbound/root.key"
server:
verbosity: 1
num-threads: 4                                                       
interface: 192.168.1.1
do-ip4: yes
do-udp: yes
do-tcp: yes
access-control: 192.168.1.0/24 allow  # Specify the subnets you want to listen on
access-control: 192.168.2.0/24 allow
do-not-query-localhost: no
chroot: ""     
logfile: "/var/log/unbound.log"           
use-syslog: no
hide-identity: yes
hide-version: yes
harden-glue: yes
harden-dnssec-stripped: yes
use-caps-for-id: yes     
private-domain: "<HOSTNAME>"     
#local-zone: "localhost." static
#local-data: "freebox.localhost. IN A 192.168.0.254"                                             
#local-data-ptr: "192.168.0.254 freebox.localhost"
python:
remote-control:
forward-zone:
  name: "."
  forward-addr: 127.0.0.2@53</pre>


=== /etc/network/interfaces ===
    # specify the interfaces to answer queries from by ip-address.
You'll need a second loopback device, put it under the already existing one.
    # The default is to listen to localhost (127.0.0.1 and ::1).
    # specify 0.0.0.0 and ::0 to bind to all available interfaces.
    # specify every interface[@port] on a new 'interface:' labelled line.
    # The listen interfaces are not changed on reload, only on restart.
    interface: 192.168.2.1
    interface: 192.168.3.1


<pre># Loopback interfaces
    # Enable IPv4, "yes" or "no".
auto lo
    do-ip4: yes
iface lo inet loopback
  address 127.0.0.1
  netmask 255.0.0.0


auto lo:1
    # Enable IPv6, "yes" or "no".
iface lo:1 inet static
    do-ip6: yes
  address 127.0.0.2
  netmask 255.0.0.0</pre>


== Blocking nasties on the network by domain ==
    # Enable UDP, "yes" or "no".
It seems Microsoft has added a whole bunch of telemetry (spyware) analytics to Windows itself, whereby the OS now calls home with various information regarding it's usage. Back porting to previous versions of Windows is not an option, because the telemetry patches have also been back ported to 7/8.1.
    do-udp: yes


Changing the knobs in Windows to stop this activity doesn't silence it completely, and they can always be reset with another update from Microsoft. It is however unlikely they will change the domains that are looked up. More information about that can be found [https://www.privacytools.io/#win10 here]. You should also consider ditching Windows entirely and using a proper operating system that does not contain intrusive malware [https://www.privacytools.io/#os here are a few choices to consider].
    # Enable TCP, "yes" or "no".
    do-tcp: yes


As this is a network router, it might be prudent to block those domains.
    # control which clients are allowed to make (recursive) queries
    # to this server. Specify classless netblocks with /size and action.
    # By default everything is refused, except for localhost.
    # Choose deny (drop message), refuse (polite error reply),
    # allow (recursive ok), allow_setrd (recursive ok, rd bit is forced on),
    # allow_snoop (recursive and nonrecursive ok)
    # deny_non_local (drop queries unless can be answered from local-data)
    # refuse_non_local (like deny_non_local but polite error reply).
    # access-control: 0.0.0.0/0 refuse
    # access-control: 127.0.0.0/8 allow
    # access-control: ::0/0 refuse
    # access-control: ::1 allow
    # access-control: ::ffff:127.0.0.1 allow
    access-control: 192.168.1.0/24 allow
    access-control: 192.168.2.0/24 allow
    access-control: 192.168.3.0/24 allow


This script takes in a list of domains and produces a filter file. We are directing all lookups to "0.0.0.1" which is an invalid IP and should fail immediately, unlike localhost. There are lists of the addresses in various places such as [https://www.reddit.com/r/privacy/comments/3htei2/stop_windows_10_from_phoning_home_by_blocking/cuafuvg here] and in this [https://github.com/10se1ucgo/DisableWinTracking/blob/master/run.py#L188 script].
    # the log file, "" means log to stderr.
    # Use of this option sets use-syslog to "no".
    logfile: "/var/log/unbound/unbound.log"


You could also use this to block advertising, but that's probably easier to do in a web browser with something like [https://en.wikipedia.org/wiki/UBlock UBlock/UBlock Origin].
    # Log to syslog(3) if yes. The log facility LOG_DAEMON is used to
    # log to. If yes, it overrides the logfile.
    use-syslog: no


=== /etc/unbound/unbound.conf ===
    # print one line with time, IP, name, type, class for every query.
In your main unbound configuration add
    # log-queries: no
<pre>include: /etc/unbound/filter.conf</pre>


=== Script to prepare/sort domains for Unbound  ===
    # print one line per reply, with time, IP, name, type, class, rcode,
<pre>#!/bin/sh
    # timetoresolve, fromcache and responsesize.
    # log-replies: no


##################################################
    # enable to not answer id.server and hostname.bind queries.
# Script taken from http://npr.me.uk/unbound.html
    hide-identity: yes
# Note you need GNU sed
##################################################


# Remove "#" comments
    # enable to not answer version.server and version.bind queries.
# Remove space and tab
    # hide-version: yes
# Remove blank lines
# Remove localhost and broadcasthost lines
# Keep just the hosts
# Remove leading and trailing space and tab (again)
# Make everything lower case


sed -e "s/#.*//" \
    # enable to not answer trustanchor.unbound queries.
    -e "s/[ \x09]*$//"\
     hide-trustanchor: yes
    -e "/^$/ d" \
    -e "/^.*local.*/ d" \
    -e "/^.*broadcasthost.*/ d" \
    -e "s/\(^.*\) \([a-zA-Z0-9\.\-]*\)/\2/" \
    -e "s/^[ \x09]*//;s/[ \x09]*$//" $1 \
     -e "s/\(.*\)/\L\1/" hosts.txt > temp1.txt


# Remove any duplicate hosts


sort temp1.txt | uniq >temp2.txt
    # Harden against very small EDNS buffer sizes.
    harden-short-bufsize: yes
 
    # Harden against unseemly large queries.
    harden-large-queries: yes
 
    # Harden against out of zone rrsets, to avoid spoofing attempts.
    harden-glue: yes
 
    # Harden against receiving dnssec-stripped data. If you turn it
    # off, failing to validate dnskey data for a trustanchor will
    # trigger insecure mode for that zone (like without a trustanchor).
    # Default on, which insists on dnssec data for trust-anchored zones.
    harden-dnssec-stripped: yes
 
    # Harden against queries that fall under dnssec-signed nxdomain names.
    harden-below-nxdomain: yes
 
    # Harden the referral path by performing additional queries for
    # infrastructure data.  Validates the replies (if possible).
    # Default off, because the lookups burden the server.  Experimental
    # implementation of draft-wijngaards-dnsext-resolver-side-mitigation.
    # harden-referral-path: no
 
    # Harden against algorithm downgrade when multiple algorithms are
    # advertised in the DS record.  If no, allows the weakest algorithm
    # to validate the zone.
    harden-algo-downgrade: yes
 
    # Use 0x20-encoded random bits in the query to foil spoof attempts.
    # This feature is an experimental implementation of draft dns-0x20.
    use-caps-for-id: yes
 
    # Allow the domain (and its subdomains) to contain private addresses.
    # local-data statements are allowed to contain private addresses too.
    private-domain: "<HOSTNAME>"
 
    # if yes, the above default do-not-query-address entries are present.
    # if no, localhost can be queried (for testing and debugging).
    do-not-query-localhost: no
 
    # File with trusted keys, kept uptodate using RFC5011 probes,
    # initial file like trust-anchor-file, then it stores metadata.
    # Use several entries, one per domain name, to track multiple zones.
    #
    # If you want to perform DNSSEC validation, run unbound-anchor before
    # you start unbound (i.e. in the system boot scripts).  And enable:
    # Please note usage of unbound-anchor root anchor is at your own risk
    # and under the terms of our LICENSE (see that file in the source).
    # auto-trust-anchor-file: "@UNBOUND_ROOTKEY_FILE@"
    auto-trust-anchor-file: "/etc/unbound/root.key"
 
    # If unbound is running service for the local host then it is useful
    # to perform lan-wide lookups to the upstream, and unblock the
    # long list of local-zones above.  If this unbound is a dns server
    # for a network of computers, disabled is better and stops information
    # leakage of local lan information.
    unblock-lan-zones: no


# Remove any hosts starting with "."
    # If you configure local-data without specifying local-zone, by
# Create the two required lines for each host.
    # default a transparent local-zone is created for the data.
    #
    # You can add locally served data with
    # local-zone: "local." static
    # local-data: "mycomputer.local. IN A 192.0.2.51"
    # local-data: 'mytext.local TXT "content of text record"'


sed -e "/^\..*/ d" \
    # request upstream over TLS (with plain DNS inside the TLS stream).
     -e "s/\(^.*\)/local-zone: \x22\1\x22 redirect\nlocal-data: \x22\1 A 0.0.0.1\x22/" \
     # Default is no.  Can be turned on and off with unbound-control.
      temp2.txt > filter.conf
    # tls-upstream: no


# Clean up
    # Forward zones
rm temp1.txt
    # Create entries like below, to make all queries for 'example.com' and
rm temp2.txt</pre>
    # 'example.org' go to the given list of servers. These servers have to handle
    # recursion to other nameservers. List zero or more nameservers by hostname
    # or by ipaddress. Use an entry with name "." to forward all queries.
    # If you enable forward-first, it attempts without the forward if it fails.
    # forward-zone:
    #    name: "example.com"
    #    forward-addr: 192.0.2.68
    #    forward-addr: 192.0.2.73@5355  # forward to port 5355.
    #    forward-first: no
    #    forward-tls-upstream: no
    #    forward-no-cache: no
    # forward-zone:
    #    name: "example.org"
    #    forward-host: fwd.example.com


== /etc/unbound/filter.conf ==
forward-zone:
<pre>local-zone: "a-0001.a-msedge.net" redirect
    name: "."
local-data: "a-0001.a-msedge.net A 0.0.0.1"
    forward-addr: 172.16.32.1@53
local-zone: "a-0002.a-msedge.net" redirect
    forward-addr: ::1@53000
local-data: "a-0002.a-msedge.net A 0.0.0.1"
    forward-addr: 127.0.0.1@53000</pre>
local-zone: "a-0003.a-msedge.net" redirect
 
local-data: "a-0003.a-msedge.net A 0.0.0.1"
== Blocking Microsoft Telemetry on the network by domain ==
local-zone: "a-0004.a-msedge.net" redirect
Microsoft has added telemetry analytics to Windows which you may want to block at a network level. More information about that can be found [https://www.privacytools.io/operating-systems/#win10 here].
local-data: "a-0004.a-msedge.net A 0.0.0.1"
 
local-zone: "a-0005.a-msedge.net" redirect
This script takes in a list of domains and produces a filter file. We are directing all lookups to "0.0.0.1" which is an invalid IP and should fail immediately, unlike localhost. There are lists of the addresses in various places such as the tools people use to do this locally on Windows, ie [https://github.com/Nummer/Destroy-Windows-10-Spying/blob/master/DWS/DWSResources.cs#L210 Destroy-Windows-10-Spying], [https://github.com/10se1ucgo/DisableWinTracking/blob/master/dwt.py#L333 DisableWinTracking], [https://github.com/W4RH4WK/Debloat-Windows-10/blob/master/scripts/block-telemetry.ps1#L19 Debloat-Windows-10] and [https://github.com/pragmatrix/Dominator/blob/master/Dominator.Windows10/Settings/telemetry.txt Dominator.Windows10]. I have prepared the list further down: [[Linux Router with VPN on a Raspberry Pi#/etc/unbound/filter.conf]].
local-data: "a-0005.a-msedge.net A 0.0.0.1"
 
local-zone: "a-0006.a-msedge.net" redirect
You could also use this to block advertising, but that's probably easier to do in a web browser with something like [https://en.wikipedia.org/wiki/uBlock_Origin uBlock Origin].
local-data: "a-0006.a-msedge.net A 0.0.0.1"
 
local
Another way is to disable this stuff with a group policy see [https://docs.microsoft.com/en-us/windows/privacy/manage-connections-from-windows-operating-system-components-to-microsoft-services Manage connections from Windows operating system components to Microsoft services] only for Windows 10 Enterprise, version 1607 and newer and Windows Server 2016.
 
=== /etc/unbound/unbound.conf ===
In your main unbound configuration add
<pre>include: /etc/unbound/filter.conf</pre>
 
=== Script to prepare/sort domains for Unbound  ===
<pre>#!/bin/sh
 
##################################################
# Script taken from http://npr.me.uk/unbound.html
# Note you need GNU sed
##################################################
 
# Remove "#" comments
# Remove space and tab
# Remove blank lines
# Remove localhost and broadcasthost lines
# Keep just the hosts
# Remove leading and trailing space and tab (again)
# Make everything lower case
 
sed -e "s/#.*//" \
    -e "s/[ \x09]*$//"\
    -e "/^$/ d" \
    -e "/^.*local.*/ d" \
    -e "/^.*broadcasthost.*/ d" \
    -e "s/\(^.*\) \([a-zA-Z0-9\.\-]*\)/\2/" \
    -e "s/^[ \x09]*//;s/[ \x09]*$//" $1 \
    -e "s/\(.*\)/\L\1/" hosts.txt > temp1.txt
 
# Remove any duplicate hosts
 
sort temp1.txt | uniq >temp2.txt
 
# Remove any hosts starting with "."
# Create the two required lines for each host.
 
sed -e "/^\..*/ d" \
    -e "s/\(^.*\)/local-zone: \x22\1\x22 redirect\nlocal-data: \x22\1 A 0.0.0.1\x22/" \
      temp2.txt > filter.conf
 
# Clean up
rm temp1.txt
rm temp2.txt</pre>
 
== /etc/unbound/filter.conf ==
 


== rng-tools with bcm2708-rng ==
== DNSCrypt ==
All Raspberry Pis come with the bcm2708-rng random number generator on board. If you are doing this project on a Raspberry Pi then you may choose to use this also.
Configuring DNSCrypt to send it's lookups through the VPN and not directly out your ppp interface is done using a socks proxy.
 
You can test that you're not getting DNS leaks by using [https://www.dnsleaktest.com dnsleak.com] or this one from [https://www.grc.com/dns/dns.htm GRC]. Providers like CloudFlare and Google (1.1.1.1, 8.8.8.8) use [https://en.wikipedia.org/wiki/Anycast anycast] which should be pointing to a server located to where your VPN exits.
 
=== /etc/dnscrypt-proxy/dnscrypt-proxy.toml ===
Using the sample dnscrypt config is fine, you will need to make these changes:


Add the kernel module to /etc/modules:
<pre>listen_addresses = ['127.0.0.1:53000', '[::1]:53000']
{{cmd|echo "bcm2708-rng" > /etc/modules}}
proxy = "socks5://127.0.0.1:1080"</pre>


Insert module:
== Dante ==
{{cmd|modprobe bcm2708-rng}}
First install dante, you'll need to pin the testing repository. See: [[Alpine Linux package management#Repository pinning]].


Install rng-tools:
{{cmd|apk add dante-server@testing}}
{{cmd|apk add rng-tools}}


Set the random device (/dev/random) and rng device (/dev/hwrng):
Configure it like so:
{{cmd|<nowiki>sed -i 's/RNGD_OPTS="--no-drng=1 --no-tpm=1"/RNGD_OPTS="--no-drng=1 --no-tpm=1 -o \/dev\/random -r \/dev\/hwrng"/g' /etc/conf.d/rngd</nowiki>}}


Start rngd service:
=== /etc/sockd.conf ===
{{cmd|service rngd start}}
<pre>logoutput: stderr
internal: 127.0.0.1 port = 1080
external: tun0
clientmethod: none
socksmethod: none
user.unprivileged: sockd


Add service to boot:
# Allow connections from localhost to any host
{{cmd|rc-update add rngd default}}
client pass {
        from: 127.0.0.1/8 to: 0.0.0.0/0
log: error # connect/disconnect
}


You can test it with:
# Generic pass statement - bind/outgoing traffic
{{cmd|<nowiki>cat /dev/hwrng | rngtest -c 1000</nowiki>}}
socks pass {
        from: 0.0.0.0/0 to: 0.0.0.0/0
        command: bind connect udpassociate
        log: error # connect disconnect iooperation
}


You should see something like:
# Generic pass statement for incoming connections/packets
socks pass {
        from: 0.0.0.0/0 to: 0.0.0.0/0
        command: bindreply udpreply
        log: error # connect disconnect iooperation
}</pre>


<pre>rngtest 5
Finally the services to the the default run level:
Copyright (c) 2004 by Henrique de Moraes Holschuh
{{cmd|rc-update add sockd default}}
This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
{{cmd|rc-update add unbound default}}
{{cmd|rc-update add dnscrypt-proxy default}}


rngtest: starting FIPS tests...
= Random number generation =
rngtest: bits received from input: 20000032
There are two ways to assist with random number generation [[Entropy and randomness]]. This can be particularly useful if you're generating your own Diffie-Hellman nonce file, used in the [[FreeRadius EAP-TLS configuration]] section. Or for that matter any process which requires lots of random number generation such as generating certificates or public private keys.
rngtest: FIPS 140-2 successes: 1000
rngtest: FIPS 140-2 failures: 0
rngtest: FIPS 140-2(2001-10-10) Monobit: 0
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 0
rngtest: FIPS 140-2(2001-10-10) Long run: 0
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=117.709; avg=808.831; max=3255208.333)Kibits/s
rngtest: FIPS tests speed: (min=17.199; avg=22.207; max=22.653)Mibits/s
rngtest: Program run time: 25178079 microseconds</pre>


It's possible you might have a some failures. That's okay, two runs I did previously had a failure each.
== Haveged ==
[http://www.issihosts.com/haveged Haveged] is a great way to improve random number generation speed. It uses the unpredictable random number generator based upon an adaptation of the [http://www.irisa.fr/caps/projects/hipsor/ HAVEGE] algorithm.


= WiFi 802.1x EAP and FreeRadius =
Install haveged:
A more secure way than using pre-shared keys (WPA2) is to use [https://en.wikipedia.org/wiki/Extensible_Authentication_Protocol#EAP-TLS EAP-TLS] and use separate certificates for each device. See [[FreeRadius EAP-TLS configuration]]
{{cmd|apk add haveged}}


= VPN Tunnel on specific subnet =
Start haveged service:
As mentioned earlier in this article it might be useful to have a VPN subnet and a non-VPN subnet. Typically gaming consoles or computers might want low-latency connections. For this exercise we use fwmark.
{{cmd|service haveged start}}


We expand the network to look like this:
Add service to boot
{{cmd|rc-update add haveged default}}


[[File:Network diagram ipv4 tunnel.svg|900px|center|Network Diagram with IPv4 tunnel]]
Start rngd service:
{{cmd|service haveged start}}


Install the necessary packages:
Add service to boot:
{{cmd|apk add openvpn iproute2 iputils}}
{{cmd|rc-update add haveged default}}


== /etc/modules ==
== rng-tools with bcm2708-rng ==
You'll want to add the tun module
<pre>tun</pre>


== /etc/iproute2/rt_tables ==
=== Pre Alpine Linux 3.8 (which includes rngd 5) ===
Add the two routing tables to the bottom of rt_tables. It should look something like this:
All Raspberry Pis come with the bcm2708-rng random number generator on board. If you are doing this project on a Raspberry Pi then you may choose to use this also.
<pre>#
# reserved values
#
255 local
254 main
253 default
0 unspec
#
# local
#
#1 inr.ruhep
1 ISP
2 VPN</pre>


== /etc/network/interfaces ==
Add the kernel module to /etc/modules:
Next up add the virtual interface: eth0:2, just under eth0 will do, remember to add an auto command to the top.
{{cmd|echo "bcm2708-rng" > /etc/modules}}


<pre>auto eth0
Insert module:
auto eth0:2
{{cmd|modprobe bcm2708-rng}}
auto eth1
auto lo
auto ppp0


# Route to ISP subnet
Install rng-tools:
iface eth0 inet static
{{cmd|apk add rng-tools}}
  address 192.168.1.1
  netmask 255.255.255.0
  broadcast 192.168.1.255


# Route to VPN subnet
Set the random device (/dev/random) and rng device (/dev/hwrng) in /etc/conf.d/rngd
iface eth0:2 inet static
{{cmd|<nowiki>RNGD_OPTS="--no-drng=1 --no-tpm=1 -o /dev/random -r /dev/hwrng"</nowiki>}}
  address 192.168.2.1
  netmask 255.255.255.0
  broadcast 192.168.2.255
  post-up /etc/network/fwmark_rules</pre>


== /etc/sysctl.conf ==
=== Post Alpine Linux 3.8 (which includes rngd 6) ===
If you want to use fwmark rules you need to change this setting. It causes the router to still do source validation.


<pre>net.ipv4.conf.all.rp_filter = 2</pre>
With AlpineLinux 3.8 you don't have to insert the module as it is already built in the kernel.


fwmark won't work if you have this set to 1.
Additionally the syntax has changed for rngd so for /etc/conf.d/rngd you'll need


== /etc/network/fwmark_rules ==
{{cmd|<nowiki>RNGD_OPTS="-x1 -o /dev/random -r /dev/hwrng"</nowiki>}}
In this file we want to put the fwmark rules and set the correct priorities.


<pre>#!/bin/sh
Start rngd service:
{{cmd|service rngd start}}


# Normal packets to go direct out WAN
Add service to boot:
/sbin/ip rule add fwmark 1 table ISP prio 100
{{cmd|rc-update add rngd default}}


# Put packets destined into VPN when VPN is up
You can test it with:
/sbin/ip rule add fwmark 2 table VPN prio 200
{{cmd|<nowiki>cat /dev/hwrng | rngtest -c 1000</nowiki>}}


# Prevent packets from being routed out when VPN is down.
You should see something like:
# This prevents packets from falling back to the main table
# that has a priority of 32766
/sbin/ip rule add prohibit fwmark 2 prio 300</pre>


== /etc/ppp/ip-up ==
<pre>rngtest 5
Next up we want to create the routes that should be run when PPP comes online. There are special hooks we can use in ip-up and ip-down to refer to the IP address, [https://ppp.samba.org/pppd.html#sect13 ppp man file - Scripts ] You can also read about them in your man file if you have ppp-doc installed.
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


<pre>#!/bin/sh
rngtest: starting FIPS tests...
#
rngtest: bits received from input: 20000032
# This script is run by pppd when there's a successful ppp connection.
rngtest: FIPS 140-2 successes: 1000
#
rngtest: FIPS 140-2 failures: 0
rngtest: FIPS 140-2(2001-10-10) Monobit: 0
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 0
rngtest: FIPS 140-2(2001-10-10) Long run: 0
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=117.709; avg=808.831; max=3255208.333)Kibits/s
rngtest: FIPS tests speed: (min=17.199; avg=22.207; max=22.653)Mibits/s
rngtest: Program run time: 25178079 microseconds</pre>


# Flush out any old rules that might be there
It's possible you might have a some failures. That's okay, two runs I did previously had a failure each.
/sbin/ip route flush table ISP


# Add route to table from subnets on LAN
= WiFi 802.1x EAP and FreeRadius =
/sbin/ip route add 192.168.1.0/24 dev eth0 table ISP
A more secure way than using pre-shared keys (WPA2) is to use [https://en.wikipedia.org/wiki/Extensible_Authentication_Protocol#EAP-TLS EAP-TLS] and use separate certificates for each device. See [[FreeRadius EAP-TLS configuration]]
/sbin/ip route add 192.168.2.0/24 dev eth0 table ISP


# Add route from IP given by ISP to the table
= VPN Tunnel on specific subnet =
/sbin/ip rule add from ${IPREMOTE} table ISP prio 100
As mentioned earlier in this article it might be useful to have a VPN subnet and a non-VPN subnet. Typically gaming consoles or computers might want low-latency connections. For this exercise we use fwmark.


# Add a default route
We expand the network to look like this:
/sbin/ip route add table ISP default via ${IPREMOTE} dev ${IFNAME}</pre>


== /etc/ppp/ip-down ==
[[File:Network diagram ipv4 tunnel.svg|900px|center|Network Diagram with IPv4 tunnel]]
<pre>#!/bin/sh
#
# This script is run by pppd after the connection has ended.
#


# Delete the rules when we take the interface down
Install the necessary packages:
/sbin/ip rule del from ${IPREMOTE} table ISP prio 100</pre>
{{cmd|apk add openvpn iproute2 iputils}}


== /etc/openvpn/route-up-fwmark.sh ==
== /etc/modules ==
OpenVPN needs similar routing scripts and it also has it's own special hooks that allow you to specify particular values. A full list is here [https://openvpn.net/index.php/open-source/documentation/manuals/65-openvpn-20x-manpage.html#lbAS OpenVPN man file - Environmental Variables]
You'll want to add the tun module
<pre>tun</pre>


<pre>#!/bin/sh
== /etc/iproute2/rt_tables ==
Add the two routing tables to the bottom of rt_tables. It should look something like this:
<pre>#
# reserved values
#
#
# This script is run by OpenVPN when there's a successful VPN connection.
255 local
254 main
253 default
0 unspec
#
#
# local
#
#1 inr.ruhep
1 ISP
2 VPN</pre>
== /etc/network/interfaces ==
Next up add the virtual interface (really just a IP address to eth0) eth0:2, just under eth0 will do.


# Flush out any old rules that might be there
<pre># Route to VPN subnet
/sbin/ip route flush table VPN
auto eth0:2
iface eth0:2 inet static
  address 192.168.2.1
  netmask 255.255.255.0
  broadcast 192.168.2.255
  post-up /etc/network/fwmark_rules</pre>


# Add route to table from 192.168.2.0/24 subnet on LAN
== /etc/sysctl.d/local.conf ==
/sbin/ip route add 192.168.2.0/24 dev eth0 table VPN
If you want to use fwmark rules you need to change this setting. It causes the router to still do source validation.


# Add route from VPN interface IP to the VPN table
<pre># Needed to use fwmark
/sbin/ip rule add from ${ifconfig_local} table VPN prio 200
net.ipv4.conf.all.rp_filter = 2
</pre>


# Add a default route
fwmark won't work if you have this set to 1.
/sbin/ip route add default via ${ifconfig_local} dev ${dev} table VPN</pre>


== /etc/openvpn/route-pre-down-fwmark.sh ==
== /etc/network/fwmark_rules ==
In this file we want to put the fwmark rules and set the correct priorities.


<pre>#!/bin/sh
<pre>#!/bin/sh
#
# This script is run by OpenVPN after the connection has ended
#


# Delete the rules when we take the interface down
# Normal packets to go direct out WAN
/sbin/ip rule del from ${ifconfig_local} table VPN prio 200</pre>
/sbin/ip rule add fwmark 1 table ISP prio 100


What I did find was when starting and stopping the OpenVPN service if you used:
# Put packets destined into VPN when VPN is up
/sbin/ip rule add fwmark 2 table VPN prio 200


{{cmd|service openvpn stop}}
# Prevent packets from being routed out when VPN is down.
# This prevents packets from falling back to the main table
# that has a priority of 32766
/sbin/ip rule add prohibit fwmark 2 prio 300</pre>


The rules in route-pre-down-fwmark.sh were not executed.
== /etc/ppp/ip-up ==
Next up we want to create the routes that should be run when PPP comes online. There are special hooks we can use in ip-up and ip-down to refer to the IP address, [https://ppp.samba.org/pppd.html#sect13 ppp man file - Scripts ] You can also read about them in your man file if you have ppp-doc installed.


However:
<pre>#!/bin/sh
#
# This script is run by pppd when there's a successful ppp connection.
#


{{cmd|/etc/init.d/openvpn stop}}
# Flush out any old rules that might be there
/sbin/ip route flush table ISP


seemed to work correctly.
# Add route to table from subnets on LAN
/sbin/ip route add 192.168.1.0/24 dev eth0 table ISP
/sbin/ip route add 192.168.2.0/24 dev eth0 table ISP


== Advanced IPtables rules that allow us to route into our two routing tables ==
# Add route from IP given by ISP to the table
This is an expansion of the previous set of rules. It sets up NAT masquerading for the 192.168.2.0 to go through the VPN using marked packets.
/sbin/ip rule add from ${IPREMOTE} table ISP prio 100


I used these guides to write complete this:
# Add a default route
/sbin/ip route add table ISP default via ${IPREMOTE} dev ${IFNAME}</pre>


* [http://nerdboys.com/2006/05/05/conning-the-mark-multiwan-connections-using-iptables-mark-connmark-and-iproute2 Conning the Mark: Multiwan connections using IPTables, MARK, CONNMARK and iproute2 ]
== /etc/ppp/ip-down ==
* [http://nerdboys.com/2006/05/08/multiwan-connections-addendum Multiwan connections addendum]
<pre>#!/bin/sh
* [http://inai.de/images/nf-packet-flow.png Netfilter packet flow]
 
<pre>#########################################################################
# Advanced routing rule set
# Uses 192.168.1.0 via ISP
#      192.168.2.0 via VPN
#
#
# Packets to/from 192.168.1.0/24 are marked with 0x1 and routed to ISP
# This script is run by pppd after the connection has ended.
# Packets to/from 192.168.2.0/24 are marked with 0x2 and routed to VPN
#
#
#########################################################################


# Delete the rules when we take the interface down
/sbin/ip rule del from ${IPREMOTE} table ISP prio 100</pre>
== /etc/openvpn/route-up-fwmark.sh ==
OpenVPN needs similar routing scripts and it also has it's own special hooks that allow you to specify particular values. A full list is here [https://openvpn.net/index.php/open-source/documentation/manuals/65-openvpn-20x-manpage.html#lbAS OpenVPN man file - Environmental Variables]
<pre>#!/bin/sh
#
#
# NAT Table
# This script is run by OpenVPN when there's a successful VPN connection.
# This is where translation of packets happens and "forwarding" of ports
# to specific hosts.
#
#
*nat


# Set default policies for table
# Flush out any old rules that might be there
:PREROUTING ACCEPT [0:0]
/sbin/ip route flush table VPN
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]


# Port forwarding for Bittorrent
# Add route to table from 192.168.2.0/24 subnet on LAN
-A PREROUTING -i tun0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20
/sbin/ip route add 192.168.2.0/24 dev eth0 table VPN
-A PREROUTING -i tun0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20


# Allows routing to our modem subnet so we can access the web interface
# Add route from VPN interface IP to the VPN table
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE
/sbin/ip rule add from ${ifconfig_local} table VPN prio 200
-A POSTROUTING -s 192.168.2.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE


# Allows hosts of the network to use the VPN tunnel
# Add a default route
-A POSTROUTING -o tun0 -j MASQUERADE
/sbin/ip route add default via ${ifconfig_local} dev ${dev} table VPN</pre>


# Allows hosts of the network to use the PPP tunnel
== /etc/openvpn/route-pre-down-fwmark.sh ==
-A POSTROUTING -o ppp0 -j MASQUERADE
COMMIT


<pre>#!/bin/sh
#
#
# Filter Table
# This script is run by OpenVPN after the connection has ended
# This is where we decide to ACCEPT, DROP or REJECT things
#
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]


# Create rule chain per input interface for forwarding packets
# Delete the rules when we take the interface down
:FWD_ETH0 - [0:0]
/sbin/ip rule del from ${ifconfig_local} table VPN prio 200</pre>
:FWD_ETH1 - [0:0]
 
:FWD_PPP0 - [0:0]
What I did find was when starting and stopping the OpenVPN service if you used:
:FWD_TUN0 - [0:0]
 
{{cmd|service openvpn stop}}


# Create rule chain per input interface for input packets (for host itself)
The rules in route-pre-down-fwmark.sh were not executed.
:IN_ETH0 - [0:0]
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]
:IN_TUN0 - [0:0]


# Create a log drop chain
However:
:LOG_DROP - [0:0]


# Create a reject chain
{{cmd|/etc/init.d/openvpn stop}}
:LOG_REJECT - [0:0]


# Pass input packet to corresponding rule chain
seemed to work correctly.
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0
-A INPUT -i tun0 -j IN_TUN0


# Track forwarded packets
== Advanced IPtables rules that allow us to route into our two routing tables ==
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
This is an expansion of the previous set of rules. It sets up NAT masquerading for the 192.168.2.0 to go through the VPN using marked packets.


# Pass forwarded packet to corresponding rule chain
I used these guides to write complete this:
-A FORWARD -i eth0 -j FWD_ETH0
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0
-A FORWARD -i tun0 -j FWD_TUN0


# Forward traffic to ISP
* [http://nerdboys.com/2006/05/05/conning-the-mark-multiwan-connections-using-iptables-mark-connmark-and-iproute2 Conning the Mark: Multiwan connections using IPTables, MARK, CONNMARK and iproute2 ]
-A FWD_ETH0 -s 192.168.1.0/24 -j ACCEPT
* [http://nerdboys.com/2006/05/08/multiwan-connections-addendum Multiwan connections addendum]
* [http://inai.de/images/nf-packet-flow.png Netfilter packet flow]


# Forward traffic to VPN
<pre>#########################################################################
-A FWD_ETH0 -s 192.168.2.0/24 -j ACCEPT
# Advanced routing rule set
# Uses 192.168.1.0 via ISP
#      192.168.2.0 via VPN
#
# Packets to/from 192.168.1.0/24 are marked with 0x1 and routed to ISP
# Packets to/from 192.168.2.0/24 are marked with 0x2 and routed to VPN
#
#########################################################################


# Allow excepted server to be FORWARD to ppp0
#
#-A FWD_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT
# NAT Table
# This is where translation of packets happens and "forwarding" of ports
# to specific hosts.
#
*nat


# Forward SSH packets from network to modem
# Set default policies for table
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:PREROUTING ACCEPT [0:0]
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]


# Forward HTTP packets from network to modem
# Port forwarding for Bittorrent
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A PREROUTING -i tun0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A PREROUTING -i tun0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20


# Forward Bittorrent Port to workstation
# Allows routing to our modem subnet so we can access the web interface
-A FWD_TUN0 -d 192.168.2.20/32 -p tcp -m tcp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE
-A FWD_TUN0 -d 192.168.2.20/32 -p udp -m udp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A POSTROUTING -s 192.168.2.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE


# SSH to Router
# Allows hosts of the network to use the VPN tunnel
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A POSTROUTING -o tun0 -j MASQUERADE
-A IN_ETH0 -s 192.168.2.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# DNS to Router
# Allows hosts of the network to use the PPP tunnel
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
-A POSTROUTING -o ppp0 -j MASQUERADE
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
COMMIT


# FreeRadius Client (eg a UniFi AP)
#
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Filter Table
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# This is where we decide to ACCEPT, DROP or REJECT things
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]


# Ubiquiti UAP Device Discovery Broadcast
# Create rule chain per input interface for forwarding packets
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 10001 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:FWD_ETH0 - [0:0]
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]
:FWD_TUN0 - [0:0]


# NTP to Router
# Create rule chain per input interface for input packets (for host itself)
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:IN_ETH0 - [0:0]
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]
:IN_TUN0 - [0:0]


# Accept traffic to router on both subnets
# Create a log drop chain
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:LOG_DROP - [0:0]
-A IN_ETH0 -s 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Allow excepted server to be INPUT to eth0 from LAN
# Create a reject chain
#-A IN_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT
:LOG_REJECT - [0:0]


# SSH To Modem from Router
# Pass input packet to corresponding rule chain
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0
-A INPUT -i tun0 -j IN_TUN0


# HTTP To Modem from Router
# Track forwarded packets
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT


# Accept incoming tracked PPP0 connection
# Pass forwarded packet to corresponding rule chain
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -i eth0 -j FWD_ETH0
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0
-A FORWARD -i tun0 -j FWD_TUN0


# Log dropped packets coming in on PPP0
# Forward traffic to ISP
-A IN_PPP0 -j LOG --log-prefix "DROP:INPUT " --log-level 6
-A FWD_ETH0 -s 192.168.1.0/24 -j ACCEPT
-A IN_PPP0 -j LOG_DROP


# Accept incoming tracked TUN0 connection
# Forward traffic to VPN
-A IN_TUN0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FWD_ETH0 -s 192.168.2.0/24 -j ACCEPT


# Log dropped packets coming in on TUN0
# Allow excepted server to be FORWARD to ppp0
-A IN_TUN0 -j LOG --log-prefix "DROP:INPUT " --log-level 6
#-A FWD_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT
-A IN_TUN0 -j LOG_DROP
COMMIT


#
# Forward SSH packets from network to modem
# Mangle Table
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# This is the place where our markings happen, whether they be 0x1 or 0x2
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
#
*mangle


# Set default policies for table
# Forward HTTP packets from network to modem
:PREROUTING ACCEPT [0:0]
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:INPUT ACCEPT [0:0]
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]


# Restore CONNMARK to the MARK (If one doesn't exist then no mark is set)
# Forward Bittorrent Port to workstation
-A PREROUTING -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
-A FWD_TUN0 -d 192.168.2.20/32 -p tcp -m tcp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_TUN0 -d 192.168.2.20/32 -p udp -m udp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# If packet MARK is 2, then it means there is already a connection mark and the
# SSH to Router
# original packet came in on VPN
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A PREROUTING -s 192.168.2.0/24 -m mark --mark 0x2 -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Check exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) are 0x1
# DNS to Router
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -m mark --mark 0x1 -j ACCEPT
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT


# Mark packets coming from 192.168.2.0/24 are 0x2
# FreeRadius Client (eg a UniFi AP)
-A PREROUTING -s 192.168.2.0/24 -j MARK --set-xmark 0x2/0xffffffff
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# If packet MARK is 1, then it means there is already a connection mark and the
# Ubiquiti UAP Device Discovery Broadcast
# original packet came in on ISP
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 10001 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A PREROUTING -s 192.168.1.0/24 -m mark --mark 0x1 -j ACCEPT


# Mark packets 192.168.1.0/24 are 0x1
# NTP to Router
-A PREROUTING -s 192.168.1.0/24 -j MARK --set-xmark 0x1/0xffffffff
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Mark exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) as 0x1
# Accept traffic to router on both subnets
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -j MARK --set-xmark 0x1/0xffffffff
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Set mark to 0 - This is for the modem. Otherwise it will mark with 0x1 or 0x2
# Allow excepted server to be INPUT to eth0 from LAN
-A PREROUTING -d 192.168.0.1/32 -j MARK --set-xmark 0x0/0xffffffff
#-A IN_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT


# Save MARK to CONNMARK (remember iproute can't see CONNMARKs)
# SSH To Modem from Router
-A PREROUTING -j CONNMARK --save-mark --nfmask 0xffffffff --ctmask 0xffffffff
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
COMMIT</pre>


You may want to delete certain rules here that do not apply to you, eg the FreeRadius rules. That is covered later in this article.
# HTTP To Modem from Router
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


== OpenVPN Routing ==
# Accept incoming tracked PPP0 connection
Usually when you connect with OpenVPN the remote VPN server will push routes down to your system. We don't want this as we still want to be able to access the internet without the VPN. We have also created our own routes that we want to use earlier in this guide.
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT


You'll need to add this to the bottom of your OpenVPN configuration file:
# Log dropped packets coming in on PPP0
<pre># Prevents default gateway from being set on the default routing table
-A IN_PPP0 -j LOG --log-prefix "DROP:INPUT " --log-level 6
route-noexec
-A IN_PPP0 -j LOG_DROP


# Allows route-up script to be executed
# Accept incoming tracked TUN0 connection
script-security 2
-A IN_TUN0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT


# Calls custom shell script after connection to add necessary routes
# Log dropped packets coming in on TUN0
route-up /etc/openvpn/route-up-fwmark.sh
-A IN_TUN0 -j LOG --log-prefix "DROP:INPUT " --log-level 6
route-pre-down /etc/openvpn/route-pre-down-fwmark.sh</pre>
-A IN_TUN0 -j LOG_DROP
COMMIT


My VPNs are arranged like this in /etc/openvpn:
#
# Mangle Table
# This is the place where our markings happen, whether they be 0x1 or 0x2
#
*mangle


OpenVPN configuration file for that server:
# Set default policies for table
<pre>countrycode.serverNumber.openvpn.conf</pre>
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]


OpenVPN certs for that server:
# Restore CONNMARK to the MARK (If one doesn't exist then no mark is set)
<pre>countrycode.serverNumber.openvpn/countrycode.serverNumber.openvpn.crt
-A PREROUTING -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
countrycode.serverNumber.openvpn/countrycode.serverNumber.openvpn.key
 
countrycode.serverNumber.openvpn/myKey.crt
# If packet MARK is 2, then it means there is already a connection mark and the
countrycode.serverNumber.openvpn/myKey.key</pre>
# original packet came in on VPN
-A PREROUTING -s 192.168.2.0/24 -m mark --mark 0x2 -j ACCEPT


So I use this helpful script to automate the process of changing between servers:
# Check exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) are 0x1
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -m mark --mark 0x1 -j ACCEPT


<pre>#!/bin/sh
# Mark packets coming from 192.168.2.0/24 are 0x2
-A PREROUTING -s 192.168.2.0/24 -j MARK --set-xmark 0x2/0xffffffff


vpn_server_filename=$1
# If packet MARK is 1, then it means there is already a connection mark and the
# original packet came in on ISP
-A PREROUTING -s 192.168.1.0/24 -m mark --mark 0x1 -j ACCEPT


rm /etc/openvpn/openvpn.conf
# Mark packets 192.168.1.0/24 are 0x1
ln -s $vpn_server_filename /etc/openvpn/openvpn.conf
-A PREROUTING -s 192.168.1.0/24 -j MARK --set-xmark 0x1/0xffffffff
chown -R openvpn:openvpn /etc/openvpn
chmod -R a=-rwx,u=+rX /etc/openvpn
chmod u=x /etc/openvpn/*.sh*


# Mark exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) as 0x1
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -j MARK --set-xmark 0x1/0xffffffff


if grep -Fxq "#CustomStuffHere" openvpn.conf
# Set mark to 0 - This is for the modem. Otherwise it will mark with 0x1 or 0x2
then
-A PREROUTING -d 192.168.0.1/32 -j MARK --set-xmark 0x0/0xffffffff
    echo "Not adding custom routes, this server has been used previously"
else
    echo "Adding custom route rules"
   
    echo -e "#CustomStuffHere\
\n# Prevents default gateway from being set on the default routing table\
\nroute-noexec\
\n# Allows route-up script to be executed\
\nscript-security 2 \
\n# Calls custom shell script after connection to add necessary routes\
\nroute-up /etc/openvpn/route-up-fwmark.sh\
\nroute-pre-down /etc/openvpn/route-pre-down-fwmark.sh\
\n# Logging of OpenVPN to file\
\n#log /etc/openvpn/openvpn.log"\
>> /etc/openvpn/openvpn.conf
fi


echo "Remember to set BitTorrent port forward in vcp.ovpn.to control panel"</pre>
# Save MARK to CONNMARK (remember iproute can't see CONNMARKs)
-A PREROUTING -j CONNMARK --save-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT</pre>


That way I can simply change between servers by running:
You may want to delete certain rules here that do not apply to you, eg the FreeRadius rules. That is covered later in this article.
{{cmd|changevpn.sh countrycode.serverNumber.openvpn}}


and then restart openvpn. I am also reminded to put the port forward through on the VPN control panel so my BitTorrent client is connectable:
== OpenVPN Routing ==
Usually when you connect with OpenVPN the remote VPN server will push routes down to your system. We don't want this as we still want to be able to access the internet without the VPN. We have also created our own routes that we want to use earlier in this guide.


{{cmd|service openvpn restart}}
You'll need to add this to the bottom of your OpenVPN configuration file:
<pre># Prevents default gateway from being set on the default routing table
route-noexec


Finally add openvpn to the default run level
# Allows route-up script to be executed
{{cmd|rc-update add openvpn default}}
script-security 2


= Creating a LAN only Subnet =
# Calls custom shell script after connection to add necessary routes
In this section, we'll be creating a LAN only subnet. This subnet will be 192.168.3.0/24. The idea of this subnet is nodes in it cannot have their packets forwarded to the Internet, however they can be accessed via the other LAN subnets 192.168.1.0/24 and 192.168.2.0/24. This approach doesn't use VLANs although that would be recommended if you had a managed switch. The idea of this subnet is for things like WiFi access points, IP Phones which contact a local Asterisk server and of course printers.
route-up /etc/openvpn/route-up-fwmark.sh
route-pre-down /etc/openvpn/route-pre-down-fwmark.sh</pre>


At the end of this section we will have something like:
My VPNs are arranged like this in /etc/openvpn:


[[File:Network diagram ipv4 tunnel LANONLY ROUTE.svg|900px|center|Network Diagram LAN ONLY Route with IPv4]]
OpenVPN configuration file for that server:
<pre>countrycode.serverNumber.openvpn.conf</pre>


== /etc/iproute2/rt_tables ==
OpenVPN certs for that server:
First up we'll add a third routing table:
<pre>countrycode.serverNumber.openvpn/countrycode.serverNumber.openvpn.crt
countrycode.serverNumber.openvpn/countrycode.serverNumber.openvpn.key
countrycode.serverNumber.openvpn/myKey.crt
countrycode.serverNumber.openvpn/myKey.key</pre>


<pre>3 LAN</pre>
So I use this helpful script to automate the process of changing between servers:


== /etc/network/interfaces ==
<pre>#!/bin/sh
Add a an extra interface.


<pre>auto eth0
vpn_server_filename=$1
auto eth0:2
auto eth0:3
auto eth1
auto lo
auto ppp0


# LAN Only
rm /etc/openvpn/openvpn.conf
iface eth0:3 inet static
ln -s $vpn_server_filename /etc/openvpn/openvpn.conf
  address 192.168.3.1
chown -R openvpn:openvpn /etc/openvpn
  netmask 255.255.255.0
chmod -R a=-rwx,u=+rX /etc/openvpn
  broadcast 192.168.3.255
chmod u=x /etc/openvpn/*.sh*
  post-up /etc/network/route_LAN</pre>


== /etc/network/route_LAN ==
if grep -Fxq "#CustomStuffHere" openvpn.conf
This file will have our route added to it
then
    echo "Not adding custom routes, this server has been used previously"
else
    echo "Adding custom route rules"
cat <<EOF >> /etc/openvpn/openvpn.conf


<pre>#!/bin/sh
#CustomStuffHere
# Prevents default gateway from being set on the default routing table
route-noexec


# Add routes from ISP to LAN
# Allows route-up script to be executed
/sbin/ip route add 192.168.1.0/24 dev eth0 table LAN
script-security 2


# Add route from VPN to LAN
# Calls custom shell script after connection to add necessary routes
/sbin/ip route add 192.168.2.0/24 dev eth0 table LAN
route-up /etc/openvpn/route-up-fwmark.sh
route-pre-down /etc/openvpn/route-pre-down-fwmark.sh


# Add route from LAN to it's own table
# Logging of OpenVPN to file
/sbin/ip route add 192.168.3.0/24 dev eth0 table LAN</pre>
#log /etc/openvpn/openvpn.log
EOF


== /etc/ppp/ip-up ==
fi
Append a route from the LAN subnet to the ISP table
echo "Remember to set BitTorrent port forward in VPN control panel"</pre>


<pre># Add route to LAN subnet
That way I can simply change between servers by running:
/sbin/ip route add 192.168.3.0/24 dev eth0 table ISP</pre>
{{cmd|changevpn.sh countrycode.serverNumber.openvpn}}


== /etc/openvpn/route-up-fwmark.sh ==
and then restart openvpn. I am also reminded to put the port forward through on the VPN control panel so my BitTorrent client is connectable:
Append a route from the LAN subnet to the VPN table


<pre># Add route to LAN only subnet
{{cmd|service openvpn restart}}
/sbin/ip route add 192.168.3.0/24 dev eth0 table VPN</pre>


== /etc/ntpd.conf ==
Finally add openvpn to the default run level
Add a listen address for ntp (OpenNTPD).
{{cmd|rc-update add openvpn default}}


You should now have:
= Creating a LAN only Subnet =
In this section, we'll be creating a LAN only subnet. This subnet will be 192.168.3.0/24. The idea of this subnet is nodes in it cannot have their packets forwarded to the Internet, however they can be accessed via the other LAN subnets 192.168.1.0/24 and 192.168.2.0/24. This approach doesn't use VLANs although that would be recommended if you had a managed switch. The idea of this subnet is for things like WiFi access points, IP Phones which contact a local Asterisk server and of course printers.


<pre># Addresses to listen on (ntpd does not listen by default)
At the end of this section we will have something like:
listen on 192.168.1.1
listen on 192.168.2.1
listen on 192.168.3.1</pre>


Devices needing the correct time will need to use this NTP server because they will not be able to get it from the Internet.
[[File:Network diagram ipv4 tunnel LANONLY ROUTE.svg|900px|center|Network Diagram LAN ONLY Route with IPv4]]


== Blocking bogons ==
== /etc/iproute2/rt_tables ==
Our LAN now has 4 subnets in total that are possible:
First up we'll add a third routing table:


* 192.168.0.0/30 (connection between modem and router)
<pre>3 LAN</pre>
* 192.168.1.0/24 (ISP table, directly routed out WAN)
* 192.168.2.0/24 (VPN table, routed out VPN)
* 192.168.3.0/24 (Null routed subnet for LAN only hosts)
* 172.16.32.0/20 (VPN provider's network, so we can access things on the VPN's network).


Everything else should be rejected. No packets should ever be forwarded on 192.168.5.2 or 10.0.0.5 for example.
== /etc/network/interfaces ==
Add a an extra virtual interface (really just a IP address to eth0).


=== Installing ipset ===
<pre># LAN Only
Install ipset:
auto eth0:3
iface eth0:3 inet static
  address 192.168.3.1
  netmask 255.255.255.0
  broadcast 192.168.3.255
  post-up /etc/network/route_LAN</pre>
 
== /etc/network/route_LAN ==
This file will have our route added to it


{{cmd|apk add ipset}}
<pre>#!/bin/sh
 
# Add routes from ISP to LAN
/sbin/ip route add 192.168.1.0/24 dev eth0 table LAN


Add it to start up:
# Add route from VPN to LAN
{{cmd|rc-update add ipset default}}
/sbin/ip route add 192.168.2.0/24 dev eth0 table LAN


Now we need to load the lists of addresses into ipset [http://blog.ls20.com/securing-your-server-using-ipset-and-dynamic-blocklists Securing Your Server using IPset and Dynamic Blocklists] mentions a [https://gist.github.com/hwdsl2/6dce75072274abfd2781 script] which was particularly useful. This script could be run on a cron job if you wanted to regularly update it and for the full bogon list you should as they change when that address space has been allocated.
# Add route from LAN to it's own table
/sbin/ip route add 192.168.3.0/24 dev eth0 table LAN</pre>


For the purpose of this we will be using just the [https://files.pfsense.org/lists/bogon-bn-nonagg.txt bogon-bn-nonagg.txt] list.
== /etc/ppp/ip-up ==
Append a route from the LAN subnet to the ISP table


<pre>0.0.0.0/8
<pre># Add route to LAN subnet
10.0.0.0/8
/sbin/ip route add 192.168.3.0/24 dev eth0 table ISP</pre>
100.64.0.0/10
127.0.0.0/8
169.254.0.0/16
172.16.0.0/12
192.0.0.0/24
192.0.2.0/24
192.168.0.0/16
198.18.0.0/15
198.51.100.0/24
203.0.113.0/24
224.0.0.0/4
240.0.0.0/4</pre>


This is unlikely to change as it's the IPV4 [https://en.wikipedia.org/wiki/Reserved_IP_addresses Reserved IP addresses] space. The script:
== /etc/openvpn/route-up-fwmark.sh ==
Append a route from the LAN subnet to the VPN table


<pre>#! /bin/bash
<pre># Add route to LAN only subnet
/sbin/ip route add 192.168.3.0/24 dev eth0 table VPN</pre>


# /usr/local/sbin/fullbogons-ipv4
== /etc/ntpd.conf ==
# BoneKracker
Add a listen address for ntp (OpenNTPD).
# Rev. 11 October 2012
# Tested with ipset 6.13


# Purpose: Periodically update an ipset used in a running firewall to block
You should now have:
# bogons. Bogons are addresses that nobody should be using on the public
# Internet because they are either private, not to be assigned, or have
# not yet been assigned.
#
# Notes: Call this from crontab. Feed updated every 4 hours.


# target="http://www.team-cymru.org/Services/Bogons/fullbogons-ipv4.txt"
<pre># Addresses to listen on (ntpd does not listen by default)
# Use alternative URL from pfSense, due to 404 error with URL above
listen on 192.168.1.1
target="https://files.pfsense.org/lists/bogon-bn-nonagg.txt"
listen on 192.168.2.1
ipset_params="hash:net"
listen on 192.168.3.1</pre>


filename=$(basename ${target})
Devices needing the correct time will need to use this NTP server because they will not be able to get it from the Internet.
firewall_ipset=${filename%.*}          # ipset will be filename minus ext
data_dir="/var/tmp/${firewall_ipset}"  # data directory will be same
data_file="${data_dir}/${filename}"


# if data directory does not exist, create it
== Blocking bogons ==
mkdir -pm 0750 ${data_dir}
Our LAN now has 4 subnets in total that are possible:


# function to get modification time of the file in log-friendly format
* 192.168.0.0/30 (connection between modem and router)
get_timestamp() {
* 192.168.1.0/24 (ISP table, directly routed out WAN)
    date -r $1 +%m/%d' '%R
* 192.168.2.0/24 (VPN table, routed out VPN)
}
* 192.168.3.0/24 (Null routed subnet for LAN only hosts)
* 172.16.32.0/20 (VPN provider's network, so we can access things on the VPN's network).


# file modification time on server is preserved during wget download
Everything else should be rejected. No packets should ever be forwarded on 192.168.5.2 or 10.0.0.5 for example.
[ -w ${data_file} ] && old_timestamp=$(get_timestamp ${data_file})


# fetch file only if newer than the version we already have
=== Installing ipset ===
wget -qNP ${data_dir} ${target}
Install ipset:


if [ "$?" -ne "0" ]; then
{{cmd|apk add ipset}}
    logger -p cron.err "IPSet: ${firewall_ipset} wget failed."
    exit 1
fi


timestamp=$(get_timestamp ${data_file})
Add it to start up:
{{cmd|rc-update add ipset default}}


# compare timestamps because wget returns success even if no newer file
Now we need to load the lists of addresses into ipset [http://blog.ls20.com/securing-your-server-using-ipset-and-dynamic-blocklists Securing Your Server using IPset and Dynamic Blocklists] mentions a [https://gist.github.com/hwdsl2/6dce75072274abfd2781 script] which was particularly useful. This script could be run on a cron job if you wanted to regularly update it and for the full bogon list you should as they change when that address space has been allocated.
if [ "${timestamp}" != "${old_timestamp}" ]; then


    temp_ipset="${firewall_ipset}_temp"
For the purpose of this we will be using just the [https://files.pfsense.org/lists/bogon-bn-nonagg.txt bogon-bn-nonagg.txt] list.
    ipset create ${temp_ipset} ${ipset_params}


    #sed -i '/^#/d' ${data_file}            # strip comments
<pre>0.0.0.0/8
    sed -ri '/^[#< \t]|^$/d' ${data_file}  # occasionally the file has been xhtml
10.0.0.0/8
100.64.0.0/10
127.0.0.0/8
169.254.0.0/16
172.16.0.0/12
192.0.0.0/24
192.0.2.0/24
192.168.0.0/16
198.18.0.0/15
198.51.100.0/24
203.0.113.0/24
224.0.0.0/4
240.0.0.0/4</pre>


    while read network; do
This is unlikely to change as it's the IPV4 [https://en.wikipedia.org/wiki/Reserved_IP_addresses Reserved IP addresses] space. The script:
        ipset add ${temp_ipset} ${network}
    done < ${data_file}


    # if ipset does not exist, create it
<pre>#! /bin/bash
    ipset create -exist ${firewall_ipset} ${ipset_params}


    # swap the temp ipset for the live one
# /usr/local/sbin/fullbogons-ipv4
    ipset swap ${temp_ipset} ${firewall_ipset}
# BoneKracker
    ipset destroy ${temp_ipset}
# Rev. 11 October 2012
# Tested with ipset 6.13


    # log the file modification time for use in minimizing lag in cron schedule
# Purpose: Periodically update an ipset used in a running firewall to block
    logger -p cron.notice "IPSet: ${firewall_ipset} updated (as of: ${timestamp})."
# bogons. Bogons are addresses that nobody should be using on the public
# Internet because they are either private, not to be assigned, or have
# not yet been assigned.
#
# Notes: Call this from crontab. Feed updated every 4 hours.


fi</pre>
# target="http://www.team-cymru.org/Services/Bogons/fullbogons-ipv4.txt"
# Use alternative URL from pfSense, due to 404 error with URL above
target="https://files.pfsense.org/lists/bogon-bn-nonagg.txt"
ipset_params="hash:net"


Now you should see the list loaded into memory when you do:
filename=$(basename ${target})
firewall_ipset=${filename%.*}          # ipset will be filename minus ext
data_dir="/var/tmp/${firewall_ipset}"  # data directory will be same
data_file="${data_dir}/${filename}"
 
# if data directory does not exist, create it
mkdir -pm 0750 ${data_dir}


{{cmd|ipset list}}
# function to get modification time of the file in log-friendly format
get_timestamp() {
    date -r $1 +%m/%d' '%R
}


We want to save it so our router can refer to it next time it starts up so for that:
# file modification time on server is preserved during wget download
[ -w ${data_file} ] && old_timestamp=$(get_timestamp ${data_file})


{{cmd|/etc/init.d/ipset save}}
# fetch file only if newer than the version we already have
wget -qNP ${data_dir} ${target}


=== Adding our allowed networks ===
if [ "$?" -ne "0" ]; then
    logger -p cron.err "IPSet: ${firewall_ipset} wget failed."
    exit 1
fi


==== IPv4 ====
timestamp=$(get_timestamp ${data_file})
{{cmd|ipset create allowed-nets-ipv4 hash:net,iface family inet}}


Then you can add each of your allowed networks:
# compare timestamps because wget returns success even if no newer file
if [ "${timestamp}" != "${old_timestamp}" ]; then


<pre>ipset add allowed-nets-ipv4 192.168.0.0/30,eth1
    temp_ipset="${firewall_ipset}_temp"
ipset add allowed-nets-ipv4 192.168.1.0/24,eth0
    ipset create ${temp_ipset} ${ipset_params}
ipset add allowed-nets-ipv4 192.168.2.0/24,eth0
ipset add allowed-nets-ipv4 192.168.3.0/24,eth0
ipset add allowed-nets-ipv4 127.0.0.0/8,lo
ipset add allowed-nets-ipv4 172.16.32.0/20,tun0</pre>


==== IPv6 ====
    #sed -i '/^#/d' ${data_file}            # strip comments
For IPv6 if you've got any [https://en.wikipedia.org/wiki/Unique_local_address Unique local address] ranges you may choose to add them:
    sed -ri '/^[#< \t]|^$/d' ${data_file}  # occasionally the file has been xhtml


{{cmd|ipset create allowed-nets-ipv6 hash:net,iface family inet6}}
    while read network; do
        ipset add ${temp_ipset} ${network}
    done < ${data_file}


<pre>ipset add allowed-nets-ipv6 fde4:8dba:82e1::/48,tun0
    # if ipset does not exist, create it
ipset add allowed-nets-ipv6 fde4:8dba:82e1:ffff::/64,eth0</pre>
    ipset create -exist ${firewall_ipset} ${ipset_params}


    # swap the temp ipset for the live one
    ipset swap ${temp_ipset} ${firewall_ipset}
    ipset destroy ${temp_ipset}


Finally save the sets with this command so they can be loaded next boot:
    # log the file modification time for use in minimizing lag in cron schedule
    logger -p cron.notice "IPSet: ${firewall_ipset} updated (as of: ${timestamp})."


{{cmd|/etc/init.d/ipset save}}
fi</pre>


== Restricting our LAN subnet with iptables, and blocking the bogons ==
Now you should see the list loaded into memory when you do:
Finally we can apply our iptables rules, to filter both 192.168.3.0/24 and make sure that subnets like 192.168.5.0/24 are not forwarded or accessible by our router. You will need to review these rules, and remove the ones that do not apply to you.


Don't forget to change your RADIUS rules if you moved your WiFi APs into the 192.168.3.0/24 subnet. You'll also need to edit /etc/raddb/clients.conf
{{cmd|ipset list}}


I used a new table here called "raw". This table is more primitive than the filter table. It cannot have FORWARD rules or INPUT rules. Therefore you will still need a FORWARD rule in your filter table to block bogons originating from your LAN.
We want to save it so our router can refer to it next time it starts up so for that:


The only kind of rules we may use here are PREROUTING and OUTPUT. The OUTPUT rules will only filter traffic originating from our router's local processes, such as if we ran the ping command to a bogon range on the router's command prompt.
{{cmd|/etc/init.d/ipset save}}


Traffic passes over the raw table, before connecting marking as indicated by this packet flow map: [http://inai.de/images/nf-packet-flow.png Netfilter packet flow graph] this means we don't have to strip the mark off the bogon range in the mangle table anymore.
=== Adding our allowed networks ===


<pre>#########################################################################
==== IPv4 ====
# Advanced routing rule set
{{cmd|ipset create allowed-nets-ipv4 hash:net,iface family inet}}
# Uses 192.168.1.0 via ISP
#      192.168.2.0 via VPN
#      192.168.3.0 via LAN
#
# Packets to/from 192.168.1.0/24 are marked with 0x1 and routed to ISP
# Packets to/from 192.168.2.0/24 are marked with 0x2 and routed to VPN
# Packets to/from 192.168.3.0/24 are routed to LAN and not forwarded onto
#                                    the internet
#
#########################################################################


#
Then you can add each of your allowed networks:
# Raw Table
# This table is the place where we drop all illegal packets from networks that
# do not exist
#
*raw
:PREROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]


# Create a log drop chain
<pre>ipset add allowed-nets-ipv4 192.168.0.0/30,eth1
:LOG_DROP_BOGON - [0:0]
ipset add allowed-nets-ipv4 192.168.1.0/24,eth0
ipset add allowed-nets-ipv4 192.168.2.0/24,eth0
ipset add allowed-nets-ipv4 192.168.3.0/24,eth0
ipset add allowed-nets-ipv4 127.0.0.0/8,lo
ipset add allowed-nets-ipv4 172.16.32.0/20,tun0</pre>


# Create an output chain
==== IPv6 ====
:OUT_PPP0 - [0:0]
For IPv6 if you've got any [https://en.wikipedia.org/wiki/Unique_local_address Unique local address] ranges you may choose to add them:
:OUT_TUN0 - [0:0]


# Allows traffic from VPN tunnel
{{cmd|ipset create allowed-nets-ipv6 hash:net,iface family inet6}}
-A PREROUTING -s 172.16.32.0/20 -i tun0 -j ACCEPT


# Allows traffic to VPN tunnel
<pre>ipset add allowed-nets-ipv6 fde4:8dba:82e1::/48,tun0
-A PREROUTING -d 172.16.32.0/20 -j ACCEPT
ipset add allowed-nets-ipv6 fde4:8dba:82e1:ffff::/64,eth0</pre>


# Block specified bogons coming in from ISP and VPN
# (unlikely to happen as they filter them on their router)
-A PREROUTING -i ppp0 -m set --match-set bogon-bn-nonagg src -j LOG_DROP_BOGON
-A PREROUTING -i tun0 -m set --match-set bogon-bn-nonagg src -j LOG_DROP_BOGON


# Allows my excepted ranges.
Finally save the sets with this command so they can be loaded next boot:
-A PREROUTING -m set --match-set allowed-nets-ipv4 src,src -j ACCEPT


# Pass output interface to corresponding chain
{{cmd|/etc/init.d/ipset save}}
-A OUTPUT -o ppp0 -j OUT_PPP0
-A OUTPUT -o tun0 -j OUT_TUN0


# Log drop chain
== Restricting our LAN subnet with iptables, and blocking the bogons ==
-A LOG_DROP_BOGON -j LOG --log-prefix "Dropped Bogon (ipv4) : " --log-level 6
Finally we can apply our iptables rules, to filter both 192.168.3.0/24 and make sure that subnets like 192.168.5.0/24 are not forwarded or accessible by our router. You will need to review these rules, and remove the ones that do not apply to you.
-A LOG_DROP_BOGON -j DROP


# Block packets originating from the router destined to bogon ranges
Don't forget to change your RADIUS rules if you moved your WiFi APs into the 192.168.3.0/24 subnet. You'll also need to edit /etc/raddb/clients.conf
-A OUT_PPP0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON


# Blocks packets originating from the router destined to bogon ranges
I used a new table here called "raw". This table is more primitive than the filter table. It cannot have FORWARD rules or INPUT rules. Therefore you will still need a FORWARD rule in your filter table to block bogons originating from your LAN.
-A OUT_TUN0 -d 172.16.32.0/20 -j ACCEPT
-A OUT_TUN0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON
COMMIT


#
The only kind of rules we may use here are PREROUTING and OUTPUT. The OUTPUT rules will only filter traffic originating from our router's local processes, such as if we ran the ping command to a bogon range on the router's command prompt.
# NAT Table
# This is where translation of packets happens and "forwarding" of ports
# to specific hosts.
#
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]


# Port forwarding for Bittorrent
Traffic passes over the raw table, before connecting marking as indicated by this packet flow map: [http://inai.de/images/nf-packet-flow.png Netfilter packet flow graph] this means we don't have to strip the mark off the bogon range in the mangle table anymore.
-A PREROUTING -i tun0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20
-A PREROUTING -i tun0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20


# Allows routing to our modem subnet so we can access the web interface
<pre>#########################################################################
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE
# Advanced routing rule set
-A POSTROUTING -s 192.168.2.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE
# Uses 192.168.1.0 via ISP
 
#      192.168.2.0 via VPN
# Allows hosts of the network to use the VPN tunnel
#      192.168.3.0 via LAN
-A POSTROUTING -o tun0 -j MASQUERADE
#
 
# Packets to/from 192.168.1.0/24 are marked with 0x1 and routed to ISP
# Allows hosts of the network to use the PPP tunnel
# Packets to/from 192.168.2.0/24 are marked with 0x2 and routed to VPN
-A POSTROUTING -o ppp0 -j MASQUERADE
# Packets to/from 192.168.3.0/24 are routed to LAN and not forwarded onto
COMMIT
#                                   the internet
#
#########################################################################


#
#
# Filter Table
# Raw Table
# This is where we decide to ACCEPT, DROP or REJECT things
# This table is the place where we drop all illegal packets from networks that
# do not exist
#
#
*filter
*raw
:INPUT DROP [0:0]
:PREROUTING ACCEPT [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
# Create rule chain per input interface for forwarding packets
:FWD_ETH0 - [0:0]
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]
:FWD_TUN0 - [0:0]
# Create rule chain per input interface for input packets (for host itself)
:IN_ETH0 - [0:0]
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]
:IN_TUN0 - [0:0]
# Create a drop chain
:LOG_DROP - [0:0]


# Create a log drop chain
# Create a log drop chain
:LOG_DROP_BOGON - [0:0]
:LOG_DROP_BOGON - [0:0]
# Create a reject chain
:LOG_REJECT_LANONLY - [0:0]


# Create an output chain
# Create an output chain
Line 1,796: Line 2,497:
:OUT_TUN0 - [0:0]
:OUT_TUN0 - [0:0]


# Pass input packet to corresponding rule chain
# Allows traffic from VPN tunnel
-A INPUT -i lo -j ACCEPT
-A PREROUTING -s 172.16.32.0/20 -i tun0 -j ACCEPT
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0
-A INPUT -i tun0 -j IN_TUN0


# Track forwarded packets
# Allows traffic to VPN tunnel
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A PREROUTING -d 172.16.32.0/20 -j ACCEPT


# Pass forwarded packet to corresponding rule chain
# Block specified bogons coming in from ISP and VPN
-A FORWARD -i eth0 -j FWD_ETH0
# (unlikely to happen as they filter them on their router)
-A FORWARD -i eth1 -j FWD_ETH1
-A PREROUTING -i ppp0 -m set --match-set bogon-bn-nonagg src -j LOG_DROP_BOGON
-A FORWARD -i ppp0 -j FWD_PPP0
-A PREROUTING -i tun0 -m set --match-set bogon-bn-nonagg src -j LOG_DROP_BOGON
-A FORWARD -i tun0 -j FWD_TUN0
 
# Allows my excepted ranges.
-A PREROUTING -m set --match-set allowed-nets-ipv4 src,src -j ACCEPT


# Pass output interface to corresponding chain
# Pass output interface to corresponding chain
Line 1,816: Line 2,515:
-A OUTPUT -o tun0 -j OUT_TUN0
-A OUTPUT -o tun0 -j OUT_TUN0


# Forward traffic to Modem
# Log drop chain
-A FWD_ETH0 -d 192.168.0.1/32 -j ACCEPT
-A LOG_DROP_BOGON -j LOG --log-prefix "Dropped Bogon (ipv4) : " --log-level 6
-A LOG_DROP_BOGON -j DROP


# Allow routing to remote address on VPN
# Block packets originating from the router destined to bogon ranges
-A FWD_ETH0 -s 192.168.1.0/24 -d 172.16.32.1/32 -o tun0 -j ACCEPT
-A OUT_PPP0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON
-A FWD_ETH0 -s 192.168.2.0/24 -d 172.16.32.1/32 -o tun0 -j ACCEPT


# Allow forwarding from LAN hosts to LAN ONLY subnet
# Blocks packets originating from the router destined to bogon ranges
-A FWD_ETH0 -s 192.168.1.0/24 -d 192.168.3.0/24 -j ACCEPT
-A OUT_TUN0 -d 172.16.32.0/20 -j ACCEPT
-A FWD_ETH0 -s 192.168.2.0/24 -d 192.168.3.0/24 -j ACCEPT
-A OUT_TUN0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON
COMMIT


# Allow LAN ONLY subnet to contact other LAN hosts
#
-A FWD_ETH0 -s 192.168.3.0/24 -d 192.168.1.0/24 -j ACCEPT
# NAT Table
-A FWD_ETH0 -s 192.168.3.0/24 -d 192.168.2.0/24 -j ACCEPT
# This is where translation of packets happens and "forwarding" of ports
# to specific hosts.
#
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]


# Refuse to forward bogons to the internet!
# Port forwarding for Bittorrent
-A FWD_ETH0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON
-A PREROUTING -i tun0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20
-A PREROUTING -i tun0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20


# Forward traffic to ISP
# Allows routing to our modem subnet so we can access the web interface
-A FWD_ETH0 -s 192.168.1.0/24 -j ACCEPT
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE
-A POSTROUTING -s 192.168.2.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE


# Forward traffic to VPN
# Allows hosts of the network to use the VPN tunnel
-A FWD_ETH0 -s 192.168.2.0/24 -j ACCEPT
-A POSTROUTING -o tun0 -j MASQUERADE


# Prevent 192.168.3.0/24 from accessing internet
# Allows hosts of the network to use the PPP tunnel
-A FWD_ETH0 -s 192.168.3.0/24 -j LOG_REJECT_LANONLY
-A POSTROUTING -o ppp0 -j MASQUERADE
COMMIT


# Allow excepted server to be FORWARD to ppp0
#
#-A FWD_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT
# Filter Table
# This is where we decide to ACCEPT, DROP or REJECT things
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]


# Forward SSH packets from network to modem
# Create rule chain per input interface for forwarding packets
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:FWD_ETH0 - [0:0]
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]
:FWD_TUN0 - [0:0]


# Forward HTTP packets from network to mode
# Create rule chain per input interface for input packets (for host itself)
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:IN_ETH0 - [0:0]
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]
:IN_TUN0 - [0:0]


# Forward Bittorrent Port to workstation
# Create a drop chain
-A FWD_TUN0 -d 192.168.2.20/32 -p tcp -m tcp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:LOG_DROP - [0:0]
-A FWD_TUN0 -d 192.168.2.20/32 -p udp -m udp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# SSH to Router
# Create a log drop chain
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:LOG_DROP_BOGON - [0:0]
-A IN_ETH0 -s 192.168.2.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# DNS to Router
# Create a reject chain
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
:LOG_REJECT_LANONLY - [0:0]
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT


# FreeRadius Client (eg a UniFi AP)
# Create an output chain
-A IN_ETH0 -s 192.168.3.10/32 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:OUT_PPP0 - [0:0]
-A IN_ETH0 -s 192.168.3.10/32 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:OUT_TUN0 - [0:0]


# Ubiquiti UAP Device Discovery Broadcast
# Pass input packet to corresponding rule chain
-A IN_ETH0 -s 192.168.3.10/32 -p udp -m udp --dport 10001 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0
-A INPUT -i tun0 -j IN_TUN0


# NTP to Router
# Track forwarded packets
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.3.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Accept traffic to router on both subnets
# Pass forwarded packet to corresponding rule chain
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FORWARD -i eth0 -j FWD_ETH0
-A IN_ETH0 -s 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0
-A FORWARD -i tun0 -j FWD_TUN0


# Allow excepted server to be INPUT to eth0 from LAN
# Pass output interface to corresponding chain
#-A IN_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT
-A OUTPUT -o ppp0 -j OUT_PPP0
-A OUTPUT -o tun0 -j OUT_TUN0


# SSH To Modem from Router
# Forward traffic to Modem
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_ETH0 -d 192.168.0.1/32 -j ACCEPT


# HTTP To Modem from Router
# Allow routing to remote address on VPN
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_ETH0 -s 192.168.1.0/24 -d 172.16.32.1/32 -o tun0 -j ACCEPT
-A FWD_ETH0 -s 192.168.2.0/24 -d 172.16.32.1/32 -o tun0 -j ACCEPT


# Accept incoming tracked PPP0 connection
# Allow forwarding from LAN hosts to LAN ONLY subnet
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FWD_ETH0 -s 192.168.1.0/24 -d 192.168.3.0/24 -j ACCEPT
-A FWD_ETH0 -s 192.168.2.0/24 -d 192.168.3.0/24 -j ACCEPT


# Log dropped packets coming in on PPP0
# Allow LAN ONLY subnet to contact other LAN hosts
-A IN_PPP0 -j LOG --log-prefix "DROP:INPUT (ipv4) " --log-level 6
-A FWD_ETH0 -s 192.168.3.0/24 -d 192.168.1.0/24 -j ACCEPT
-A IN_PPP0 -j LOG_DROP
-A FWD_ETH0 -s 192.168.3.0/24 -d 192.168.2.0/24 -j ACCEPT
 
# Refuse to forward bogons to the internet!
-A FWD_ETH0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON


# Accept incoming tracked TUN0 connection
# Forward traffic to ISP
-A IN_TUN0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FWD_ETH0 -s 192.168.1.0/24 -j ACCEPT


# Log dropped packets coming in on TUN0
# Forward traffic to VPN
-A IN_TUN0 -j LOG --log-prefix "DROP:INPUT (ipv4) " --log-level 6
-A FWD_ETH0 -s 192.168.2.0/24 -j ACCEPT
-A IN_TUN0 -j LOG_DROP


# Log dropped bogons that never got forwarded
# Prevent 192.168.3.0/24 from accessing internet
-A LOG_DROP_BOGON -j LOG --log-prefix "Dropped Bogon forward (ipv4) " --log-level 6
-A FWD_ETH0 -s 192.168.3.0/24 -j LOG_REJECT_LANONLY
-A LOG_DROP_BOGON -j DROP


# Log rejected packets
# Allow excepted server to be FORWARD to ppp0
-A LOG_REJECT_LANONLY -j LOG --log-prefix "Rejected packet from LAN only range : " --log-level 6
#-A FWD_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT
-A LOG_REJECT_LANONLY -j REJECT --reject-with icmp-port-unreachable
COMMIT


#
# Forward SSH packets from network to modem
# Mangle Table
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# This is the place where our markings happen, whether they be 0x1 or 0x2
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
#
*mangle


# Set default policies for table
# Forward HTTP packets from network to mode
:PREROUTING ACCEPT [0:0]
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:INPUT ACCEPT [0:0]
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]


# Restore CONNMARK to the MARK (If one doesn't exist then no mark is set)
# Forward Bittorrent Port to workstation
-A PREROUTING -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
-A FWD_TUN0 -d 192.168.2.20/32 -p tcp -m tcp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_TUN0 -d 192.168.2.20/32 -p udp -m udp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# If packet MARK is 2, then it means there is already a connection mark and the
# SSH to Router
# original packet came in on VPN
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A PREROUTING -s 192.168.2.0/24 -m mark --mark 0x2 -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Check exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) are 0x1
# DNS to Router
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -m mark --mark 0x1 -j ACCEPT
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT


# Mark packets coming from 192.168.2.0/24 are 0x2
# FreeRadius Client (eg a UniFi AP)
-A PREROUTING -s 192.168.2.0/24 -j MARK --set-xmark 0x2/0xffffffff
-A IN_ETH0 -s 192.168.3.10/32 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.3.10/32 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# If packet MARK is 1, then it means there is already a connection mark and the
# Ubiquiti UAP Device Discovery Broadcast
# original packet came in on ISP
-A IN_ETH0 -s 192.168.3.10/32 -p udp -m udp --dport 10001 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A PREROUTING -s 192.168.1.0/24 -m mark --mark 0x1 -j ACCEPT


# Mark packets 192.168.1.0/24 are 0x1
# NTP to Router
-A PREROUTING -s 192.168.1.0/24 -j MARK --set-xmark 0x1/0xffffffff
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.3.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Mark exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) as 0x1
# Accept traffic to router on both subnets
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -j MARK --set-xmark 0x1/0xffffff
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


# Strip mark if packet is destined for modem
# Allow excepted server to be INPUT to eth0 from LAN
-A PREROUTING -d 192.168.0.1/32 -j MARK --set-xmark 0x0/0xffffffff
#-A IN_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT


# Save MARK to CONNMARK (remember iproute can't see CONNMARKs)
# SSH To Modem from Router
-A PREROUTING -j CONNMARK --save-mark --nfmask 0xffffffff --ctmask 0xffffffff
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
COMMIT</pre>


= IPv6 =
# HTTP To Modem from Router
IPv6 introduces a number of new complexities into our network. To begin with we're going to build a basic IPv6 network without the VPN tunnel ie 192.168.2.0/24 subnet or tun0 interface. If you've completed previous parts of this guide, you can leave that part as is.
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT


If your VPN provider only offers you a single stack connection (no IPv6) then you've got nothing there to worry about.
# Accept incoming tracked PPP0 connection
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT


In this section we will implement IPv6 dual stack. We do at this point only have dual stack, prefix delegation. If you know nothing about IPv6, then you should have a look at these helpful pages:
# Log dropped packets coming in on PPP0
-A IN_PPP0 -j LOG --log-prefix "DROP:INPUT (ipv4) " --log-level 6
-A IN_PPP0 -j LOG_DROP


* [http://tldp.org/HOWTO/Linux+IPv6-HOWTO Linux IPv6 HOWTO (en)] - in particular the "basics" and "address types".
# Accept incoming tracked TUN0 connection
* [https://en.wikipedia.org/wiki/IPv6 IPv6]
-A IN_TUN0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
* [https://en.wikipedia.org/wiki/IPv6_address IPv6 Address]
* [https://en.wikipedia.org/wiki/Prefix_delegation Prefix delegation] we use this with dhcpcd when doing DHCPv6-PD to inform our ISP of our network devices.
* [https://en.wikipedia.org/wiki/Neighbor_Discovery_Protocol Neighbor Discovery Protocol] we use this with radvd to distribute our routes.
* [https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol_version_6 Internet Control Message Protocol version 6] ICMPv6 differs from ICMPv4 and is used for many critical parts of IPv6 infrastructure.
* [http://ipv6-test.com IPv6-test.com] Useful for diagnosing if IPv6 is working.


# Log dropped packets coming in on TUN0
-A IN_TUN0 -j LOG --log-prefix "DROP:INPUT (ipv4) " --log-level 6
-A IN_TUN0 -j LOG_DROP


[[File:Network diagram ipv6 basic.svg|900px|center|Network Diagram Single IPv6]]
# Log dropped bogons that never got forwarded
-A LOG_DROP_BOGON -j LOG --log-prefix "Dropped Bogon forward (ipv4) " --log-level 6
-A LOG_DROP_BOGON -j DROP


== Enabling IPv6 support ==
# Log rejected packets
-A LOG_REJECT_LANONLY -j LOG --log-prefix "Rejected packet from LAN only range : " --log-level 6
-A LOG_REJECT_LANONLY -j REJECT --reject-with icmp-port-unreachable
COMMIT


Assuming you're using the Alpine Linux kernel, IPv6 support is available separately as a module.
#
# Mangle Table
# This is the place where our markings happen, whether they be 0x1 or 0x2
#
*mangle


{{cmd|modprobe ipv6}}
# Set default policies for table
To add the module to our startup configuration.
:PREROUTING ACCEPT [0:0]
{{cmd|echo "ipv6" >> /etc/modules}}
:INPUT ACCEPT [0:0]
 
:FORWARD ACCEPT [0:0]
=== /etc/sysctl.conf ===
:OUTPUT ACCEPT [0:0]
Modify the sysctl section to include IPv6 support:
:POSTROUTING ACCEPT [0:0]
 
<pre>########################################
###              IPv6                ###
########################################


# http://vk5tu.livejournal.com/37206.html
# Restore CONNMARK to the MARK (If one doesn't exist then no mark is set)
# What's this special value "2"? Originally the value was "1", but this
-A PREROUTING -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
# disabled autoconfiguration on all interfaces. That is, you couldn't appear
# to be a router on some interfaces and appear to be a host on other
# interfaces. But that's exactly the mental model of a ADSL router.


# Controls IP packet forwarding
# If packet MARK is 2, then it means there is already a connection mark and the
net.ipv6.conf.all.forwarding = 2
# original packet came in on VPN
net.ipv6.conf.default.forwarding = 2
-A PREROUTING -s 192.168.2.0/24 -m mark --mark 0x2 -j ACCEPT


# Enable source validation by reversed path
# Check exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) are 0x1
# Protects from attackers that are using ip spoofing methods to do harm
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -m mark --mark 0x1 -j ACCEPT
net.ipv6.conf.all.rp_filter = 1


net.ipv6.conf.all.accept_ra = 2
# Mark packets coming from 192.168.2.0/24 are 0x2
net.ipv6.conf.default.accept_ra = 2
-A PREROUTING -s 192.168.2.0/24 -j MARK --set-xmark 0x2/0xffffffff


# Disable redirects, not a router
# If packet MARK is 1, then it means there is already a connection mark and the
net.ipv6.conf.all.accept_redirects = 0
# original packet came in on ISP
net.ipv6.conf.default.accept_redirects = 0</pre>
-A PREROUTING -s 192.168.1.0/24 -m mark --mark 0x1 -j ACCEPT


===  /etc/ppp/peers/yourISP ===
# Mark packets 192.168.1.0/24 are 0x1
Add this to your ppp configuration. This tells PPP to get an ipv6 address. Note the comma is needed.
-A PREROUTING -s 192.168.1.0/24 -j MARK --set-xmark 0x1/0xffffffff


<pre># Enable IPV6
# Mark exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) as 0x1
+ipv6 ipv6cp-use-ipaddr
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -j MARK --set-xmark 0x1/0xffffff
ipv6 ,</pre>


=== Check system log ===
# Strip mark if packet is destined for modem
Restart ppp.
-A PREROUTING -d 192.168.0.1/32 -j MARK --set-xmark 0x0/0xffffffff


{{cmd|poff yourISP}}
# Save MARK to CONNMARK (remember iproute can't see CONNMARKs)
{{cmd|pon yourISP}}
-A PREROUTING -j CONNMARK --save-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT</pre>


In /var/log/messages you should see something like
= Other Tips =


<pre>pppd[]: Plugin rp-pppoe.so loaded.
== Diagnosing firewall problems ==
pppd[]: RP-PPPoE plugin version 3.8p compiled against pppd 2.4.7
pppd[]: pppd 2.4.7 started by root, uid 0
pppd[]: PPP session is 49969
pppd[]: Connected to 00:53:00:ff:ff:f0 via interface eth1
pppd[]: Using interface ppp0
pppd[]: Connect: ppp0 <--> eth1
pppd[]: CHAP authentication succeeded
pppd[]: CHAP authentication succeeded
pppd[]: peer from calling number 00:53:00:FF:FF:F0 authorized
pppd[]: local  LL address fe80::0db8:ffff:ffff:fff1
pppd[]: remote LL address fe80::0db8:ffff:ffff:fff0
pppd[]: local  IP address 192.0.2.1
pppd[]: remote IP address 192.0.2.0
pppd[]: primary  DNS address 192.0.2.10
pppd[]: secondary DNS address 192.0.2.20</pre>


You should be able to now ping things such as
=== netcat, netcat6 ===
Netcat can be useful for testing if a port is open or closed or filtered.


{{cmd|ping6 ipv6.google.com}}
{{cmd|apk add netcat-openbsd}}


from your router.
After installing netcat we can use it like this:


== Prefix Delegation ==
Say we wanted to test for IPv6, UDP, Port 547 we would do this on the router:


The next step will be to configure DHCPv6 Prefix Delegation with your ISP. Install dhcpcd. While many guides do use the wide-dhcpv6-client [http://bugs.alpinelinux.org/issues/564 it should be noted this is unmaintained] and not included in Alpine Linux.
{{cmd|nc -6 -u -l 547}}


Don't use the ISC's dhclient either as [https://bugs.gentoo.org/show_bug.cgi?id=432652 this does not support Prefix Delegations on PPP links] without a patch.
and then this on the client to connect to it:


{{cmd|apk add dhcpcd}}
{{cmd|nc -u -v -6 2001:0db8:1234:0001::1 547}}


You can check out the manual for [http://roy.marples.name/man/html5/dhcpcd.conf.html dhcpcd.conf]. Installing dhcpcd-doc will allow you to read the man file. Eg:
=== tcpdump ===


{{cmd|apk add dhcpcd-doc}}
tcpdump can also be useful for dumping the contents of packets coming in on an interface:


=== /etc/dhcpcd.conf ===
{{cmd|apk add tcpdump}}


{{cmd|apk add dhcpcd}}
Then we can run it. This example captures all DNS traffic originating from 192.168.2.20.


<pre># Enable extra debugging
{{cmd|tcpdump -i eth0 udp and src 192.168.2.20 and port 53}}
# debug


# Allow users of this group to interact with dhcpcd via the control
You can write the file out with the -w option, and view it in Wireshark locally on your computer. You can increase the verbosity with the -v option. Using -vv will be even more verbose. -vvv will show even more.
# socket.
#controlgroup wheel


# Inform the DHCP server of our hostname for DDNS.
== lbu cache ==
hostname gateway
Configure lbu cache so that you don't need to download packages when you restart your router eg [[Local APK cache]]


# Use the hardware address of the interface for the Client ID.
This is particularly important as some of the images do not contain ppp-pppoe. This might mean you're unable to get an internet connection to download the other packages on boot.
#clientid
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as
# per RFC4361. Some non-RFC compliant DHCP servers do not reply with
# this set. In this case, comment out duid and enable clientid above.
duid


# Persist interface configuration when dhcpcd exits.
== lbu encryption /etc/lbu/lbu.conf ==
persistent
In /etc/lbu/lbu.conf you might want to enable encryption to protect your VPN keys.


# Rapid commit support.
<pre># what cipher to use with -e option
# Safe to enable by default because it requires the equivalent option
DEFAULT_CIPHER=aes-256-cbc
# set on the server to actually work.
option rapid_commit


# A list of options to request from the DHCP server.
# Uncomment the row below to encrypt config by default
option domain_name_servers, domain_name, domain_search, host_name
ENCRYPTION=$DEFAULT_CIPHER
option classless_static_routes


# Most distributions have NTP support.
# Uncomment below to avoid <media> option to 'lbu commit'
option ntp_servers
# Can also be set to 'floppy'
# Respect the network MTU.
LBU_MEDIA=mmcblk0p1
# Some interface drivers reset when changing the MTU so disabled by
# default.
#option interface_mtu


# A ServerID is required by RFC2131.
# Set the LBU_BACKUPDIR variable in case you prefer to save the apkovls
require dhcp_server_identifier
# in a normal directory instead of mounting an external media.
# LBU_BACKUPDIR=/root/config-backups


# Generate Stable Private IPv6 Addresses instead of hardware based
# Uncomment below to let lbu make up to 3 backups
# ones
# BACKUP_LIMIT=3</pre>
slaac private


# A hook script is provided to lookup the hostname if not set by the
Remember to set a root password, by default Alpine Linux's root account is passwordless.
# DHCP server, but it should not be run by default.
{{cmd|passwd root}}
nohook lookup-hostname


# IPv6 Only
== Backup apkprov ==
ipv6only
It's a good idea to back up your apk provision file. You can pull it off your router to your local workstation with:


# Disable solicitations on all interfaces
{{cmd|scp -r root@192.168.2.1:/media/mmcblk0p1/<YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc ./}}
noipv6rs


# Wait for IP before forking to background
And decrypt it with:
waitip 6
{{cmd|openssl enc -d -aes-256-cbc -in <YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc -out <YOUR HOST NAME>.apkovl.tar.gz}}


# Don't install any default routes.  
It can be encrypted with:
# PPP has already set a default route
{{cmd|openssl aes-256-cbc -salt -in <YOUR HOST NAME>.apkovl.tar.gz -out <YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc}}
nogateway


# Don't touch DNS
== Harden SSH ==
nohook resolv.conf


# Use the interface connected to WAN
=== Generate a SSH key ===
interface ppp0
{{cmd|ssh-keygen -t rsa -b 4096}}
    ipv6rs # enable routing solicitation get the default IPv6 route
    iaid 1
    ia_pd 1/::/64 eth0/1/64 # Assign a prefix delegated route to our LAN</pre>


Add dhcpcd to the default run level:
You will want to put the contents of id_rsa.pub in /etc/ssh/authorized_keys


{{cmd|rc-update add dhcpcd default}}
You can put multiple public keys on multiple lines if more than one person has access to the router.


== Configure ip6tables with a basic ruleset ==
=== /etc/ssh/sshd_config ===
A couple of good options to set in here can be:


A basic rule set for ip6tables. It is commented so feel free to read it.
<pre>ListenAddress 192.168.1.1
ListenAddress 192.168.2.1</pre>


You'll need to modify your prefix in one of the rules.
While this isn't usually a good idea, a router doesn't need more than one user.
<pre>PermitRootLogin yes</pre>


<pre>#########################################################################
The most important options:
# Basic iptables IPv6 routing rule set
<pre>RSAAuthentication yes
#
PubkeyAuthentication yes
# 2001:0db8:1234:0001::/64 hosts  routed directly to ppp0
AuthorizedKeysFile  /etc/ssh/authorized_keys
#
PasswordAuthentication no
#########################################################################
PermitEmptyPasswords no
AllowTcpForwarding no
X11Forwarding no</pre>


*mangle
=== /etc/conf.d/sshd ===
:PREROUTING ACCEPT [0:0]
You will want to add <pre>rc_need="net"</pre>
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
COMMIT


*nat
This instructs OpenRC to make sure the network is up before starting ssh.
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
COMMIT


*raw
Finally add sshd to the default run level
:PREROUTING ACCEPT [0:0]
{{cmd|rc-update add sshd default}}
:OUTPUT ACCEPT [0:0]
COMMIT
 
#
# Filter Table
# This is where we decide to ACCEPT, DROP or REJECT things
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
 
# Create rule chain per input interface for forwarding packets
:FWD_ETH0 - [0:0]
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]
:FWD_TUN0 - [0:0]


# Create ICMPFLOOD chain
:ICMPFLOOD - [0:0]


# Create rule chain per input interface for input packets (for host itself)
Additionally you may want to look at [https://stribika.github.io/2015/01/04/secure-secure-shell.html Secure Secure Shell] and tighten OpenSSH's cryptography options.
:IN_ETH0 - [0:0]
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]


# Create a drop chain
= References =
:LOG_DROP - [0:0]
* https://wiki.gentoo.org/wiki/Home_Router
 
* https://help.ubuntu.com/community/ADSLPPPoE
# Accept all from localhost
* https://wiki.archlinux.org/index.php/Router
-A INPUT -i lo -j ACCEPT
* https://wiki.gentoo.org/wiki/IPv6_router_guide
 
* [https://vk5tu.livejournal.com/37206.html IPv6 at home, under the hood with Debian Wheezy and Internode]
# Create rule chain per input interface for input packets (for host itself)
* [http://vk5tu.livejournal.com/43059.html Raspberry Pi random number generator]
-A INPUT -i eth0 -j IN_ETH0
* [https://www.raspberrypi.org/forums/viewtopic.php?f=56&t=60569 rng-tools post by ktb]
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0
 
# Block remote packets claiming to be from a loopback address
-A INPUT -s ::1/128 ! -i lo -j DROP
 
# Permit needed ICMP packet types for IPv6 per RFC 4890
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 1 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 2 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 3 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 4 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 133 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 134 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 135 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 136 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 137 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 141 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 142 -j ACCEPT
-A INPUT -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 130 -j ACCEPT
-A INPUT -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 131 -j ACCEPT
-A INPUT -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 132 -j ACCEPT
-A INPUT -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 143 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 148 -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 149 -j ACCEPT
-A INPUT -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 151 -j ACCEPT
-A INPUT -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 152 -j ACCEPT
-A INPUT -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 153 -j ACCEPT
 
# Permit ICMP echo requests (ping) and use ICMPFLOOD chain for preventing ping flooding.
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 128 -j ICMPFLOOD
 
# Track forwarded packets
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
 
# Pass forwarded packet to corresponding rule chain
-A FORWARD -i eth0 -j FWD_ETH0
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0
 
# Permit needed ICMP packet types for IPv6 per RFC 4890
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 1 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 2 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 3 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 4 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 133 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 134 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 135 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 136 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 137 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 141 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 142 -j ACCEPT
-A FORWARD -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 130 -j ACCEPT
-A FORWARD -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 131 -j ACCEPT
-A FORWARD -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 132 -j ACCEPT
-A FORWARD -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 143 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 148 -j ACCEPT
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 149 -j ACCEPT
-A FORWARD -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 151 -j ACCEPT
-A FORWARD -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 152 -j ACCEPT
-A FORWARD -s fe80::/10 -p ipv6-icmp -m icmp6 --icmpv6-type 153 -j ACCEPT
 
# Permit ICMP echo requests (ping) and use ICMPFLOOD chain for preventing ping flooding.
-A FORWARD -p ipv6-icmp -m icmp6 --icmpv6-type 128 -j ICMPFLOOD
 
# Forward LAN subnet
-A FWD_ETH0 -s 2001:0db8:1234:0001::/64 -j ACCEPT
 
# Chain for preventing ping flooding - up to 6 pings per second from a single
# source, again with log limiting.
-A ICMPFLOOD -m hashlimit --hashlimit-name ICMP --hashlimit-above 6/second --hashlimit-mode srcip -j DROP
-A ICMPFLOOD -j ACCEPT
 
# DHCPv6 to Router
-A IN_ETH0 -p udp -m udp --dport 547 -m conntrack --ctstate NEW -j ACCEPT
 
# LAN traffic out
-A IN_ETH0 -s 2001:0db8:1234:0001::/64 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
 
# Accept tracked connections from outside
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
 
# Drop and log everything else
-A IN_PPP0 -j LOG --log-prefix "DROP:INPUT (ipv6) " --log-level 6
-A IN_PPP0 -j LOG_DROP
COMMIT</pre>
 
Add ip6tables to the default run level:
 
{{cmd|rc-update add ip6tables default}}
 
== Router Advertisements ==
 
{{cmd|apk add radvd}}
 
Once radvd is installed, you may configure it:
 
=== /etc/radvd.conf ===
Note this will cause an IPv6 address to be routed to your systems. Those '''systems will now leak via IPv6 to the Internet''' if you're on a subnet like 192.168.2.0/24 using an aliased connection.
 
To mitigate this we would use VLANs, which behave as separate network interfaces. For that you need to replaced the unmanaged switch with a managed one, and each interface, eg eth0:2 with eth0.2.
 
<pre>interface eth0 {
 
  # We are sending advertisements (route)
  AdvSendAdvert on;
 
  # Suggested Maximum Transmission setting for using the
  # Hurricane Electric Tunnel Broker.
  # AdvLinkMTU 1480;
 
  # We have native Dual Stack IPv6 so we can use the regular MTU
  # http://blogs.cisco.com/enterprise/ipv6-mtu-gotchas-and-other-icmp-issues
  AdvLinkMTU 1500;
 
  prefix 2001:0db8:1234:b001::/64 {
    AdvOnLink on;
    AdvAutonomous on; # SLAAC based on EUI
    AdvRouterAddr on;
  };
 
  RDNSS 2001:0db8:1234:0001::1 {
  };
  # DNSSL example.id.au {
  # };
};</pre>
 
Add radvd to the default run level:
 
{{cmd|rc-update add radvd default}}
 
== Enable Privacy extensions in /etc/sysctl.conf ==
 
When a client acquires an address through SLAAC its IPv6 address is derived from the advertised prefix and the MAC address of the network interface of the client. This may raise security concerns as the MAC address of the computer can be easily derived by the IPv6 address. In order to tackle this problem the ''IPv6 Privacy Extensions'' standard ([https://tools.ietf.org/html/rfc4941 RFC 4941]) has been developed. With privacy extensions the kernel generates a ''temporary'' address that is mangled from the original autoconfigured address. Private addresses are preferred when connecting to a remote server so the original address is hidden. To enable Privacy Extensions reproduce the following steps:
 
<pre># Enable IPv6 Privacy Extensions
net.ipv6.conf.all.use_tempaddr = 2
net.ipv6.conf.default.use_tempaddr = 2
net.ipv6.conf.nic0.use_tempaddr = 2
...
net.ipv6.conf.nicN.use_tempaddr = 2</pre>
 
== Using DHCPv6 ==
You may decide you want more control over your network address assignment. For this you'll need to use DHCPv6. DHCPv4 and DHCPv6 need to run on separate instances of DHCPD.
 
Make a symlink for the init script:
{{cmd|ln -s /etc/init.d/dhcpd /etc/init.d/dhcpdv6}}
 
Include it in the router provision file:
{{cmd|lbu include /etc/init.d/dhcpdv6}}
 
Copy the DHCP Daemon configuration file:
{{cmd|cp /etc/conf.d/dhcpd /etc/conf.d/dhcpdv6}}
 
Enable it to run on IPv6. DHCPD can only run on one IP protocol at a time. By default it defaults to IPv4.
{{cmd|<nowiki>sed -i 's/# DHCPD_OPTS=""/DHCPD_OPTS="-6"/g' /etc/conf.d/dhcpdv6</nowiki>}}
 
Copy the DHCP configuration file:
{{cmd|cp /etc/dhcp/dhcpd.conf /etc/dhcp/dhcpdv6.conf}}
 
Change the owner of the configurations to the dhcp user and group
{{cmd|chown -R dhcp:dhcp /etc/dhcp}}
 
=== /etc/dhcp/dhcpdv6.conf ===
You will want to edit your MAC address in the host declarations. The client-id or DUID can be found in /etc/dhcpcd.duid when you've installed dhcpcd on your client.
 
You can also see it in /var/log/messages on your router when a client tries to authenticate on your network eg:
 
<pre>dhcpd: Advertise NA: address 2001:0db8:1234:0001::240 to client with duid <DEVICE DUID> iaid = <DEVICE IAID> valid for 43200 seconds</pre>
 
Currently [https://code.google.com/p/android/issues/detail?id=32621 Android does not have DHCPv6 support] and Google seem unwilling to add it.
 
If you're using a version of dhcpcd below 6.9.3 you may need to set "ipv6ra_accept_nopublic" in your /etc/dhcpcd.conf.
 
<pre>authoritative;
ddns-update-style interim;
 
shared-network home {
  subnet6 2001:0db8:1234:0001::/64 {
    range6 2001:0db8:1234:0001::10 2001:0db8:1234:0001::240;
    range6 2001:0db8:1234:0001:: temporary;
    option dhcp6.name-servers 2001:0db8:1234:0001::1;
    option dhcp6.sntp-servers 2001:0db8:1234:0001::1;
    allow unknown-clients;
  }
 
  subnet6 fde4:8dba:82e1:ffff::/64 {
    range6 fde4:8dba:82e1:ffff::10 fde4:8dba:82e1:ffff::240;
    range6 fde4:8dba:82e1:ffff:: temporary;
    option dhcp6.name-servers 2001:0db8:1234:0001::1;
    option dhcp6.sntp-servers 2001:0db8:1234:0001::1;
    ignore unknown-clients;
  }
}
 
host Gaming_Computer {
  hardware ethernet 00:53:00:FF:FF:11;;
  host-identifier option dhcp6.client-id <YOUR_DUID>;
  fixed-address6 2001:0db8:1234:0001::20;
  fixed-prefix6 2001:0db8:1234:0001::/64;
  option dhcp6.name-servers 2001:0db8:1234:0001::1;
  option dhcp6.sntp-servers 2001:0db8:1234:0001::1;
}
 
host Linux Workstation {
  hardware ethernet 00:53:00:FF:FF:22;;
  host-identifier option dhcp6.client-id <YOUR_DUID>;
  fixed-address6 fde4:8dba:82e1:ffff::21;
  fixed-prefix6 2001:0db8:1234:0001::/64;
  option dhcp6.name-servers 2001:0db8:1234:0001::1;
  option dhcp6.sntp-servers 2001:0db8:1234:0001::1;
}</pre>
 
=== /etc/radvd.conf ===
Finally you'll want to change add "AdvManagedFlag", and "AdvOtherConfigFlag". You will also want to toggle "AdvAutonomous" to off if you do not want IPs generated by SLAAC based on EUI.
 
<pre>interface eth0 {
 
  # We are sending advertisements (route)
  AdvSendAdvert on;
 
  # When set, host use the administered (stateful) protocol
  # for address autoconfiguration. The use of this flag is
  # described in RFC 4862
  AdvManagedFlag on;
 
  # When set, host use the administered (stateful) protocol
  # for address autoconfiguration. For other (non-address)
  # information.
  # The use of this flag is described in RFC 4862
  AdvOtherConfigFlag on;
 
  # Suggested Maximum Transmission setting for using the
  # Hurricane Electric Tunnel Broker.
  # AdvLinkMTU 1480;
 
  # We have native Dual Stack IPv6 so we can use the regular MTU
  # http://blogs.cisco.com/enterprise/ipv6-mtu-gotchas-and-other-icmp-issues
  AdvLinkMTU 1500;
 
  prefix 2001:0db8:1234:0001::/64 {
    AdvOnLink on;
    AdvAutonomous off;
    AdvRouterAddr on;
  };
 
  # RDNSS 2001:0db8:1234:0001::1 {
  # };
  # DNSSL example.id {
  # };
};</pre>
 
= Other Tips =
 
== Diagnosing firewall problems ==
 
=== netcat, netcat6 ===
Netcat can be useful for testing if a port is open or closed or filtered.
 
{{cmd|apk add netcat-openbsd}}
 
After installing netcat we can use it like this:
 
Say we wanted to test for IPv6, UDP, Port 547 we would do this on the router:
 
{{cmd|nc -6 -u -l 547}}
 
and then this on the client to connect to it:
 
{{cmd|nc -u -v -6 2001:0db8:1234:0001::1 547}}
 
=== tcpdump ===
 
tcpdump can also be useful for dumping the contents of packets coming in on an interface:
 
{{cmd|apk add tcpdump}}
 
Then we can run it. This example captures all DNS traffic originating from 192.168.2.20.
 
{{cmd|tcpdump -i eth0 udp and src 192.168.2.20 and port 53}}
 
You can write the file out with the -w option, and view it in Wireshark locally on your computer. You can increase the verbosity with the -v option. Using -vv will be even more verbose. -vvv will show even more.
 
== lbu cache ==
Configure lbu cache so that you don't need to download packages when you restart your router eg [[Local APK cache]]
 
This is particularly important as some of the images do not contain ppp-pppoe. This might mean you're unable to get an internet connection to download the other packages on boot.
 
== lbu encryption /etc/lbu/lbu.conf ==
In /etc/lbu/lbu.conf you might want to enable encryption to protect your VPN keys.
 
<pre># what cipher to use with -e option
DEFAULT_CIPHER=aes-256-cbc
 
# Uncomment the row below to encrypt config by default
ENCRYPTION=$DEFAULT_CIPHER
 
# Uncomment below to avoid <media> option to 'lbu commit'
# Can also be set to 'floppy'
LBU_MEDIA=mmcblk0p1
 
# Set the LBU_BACKUPDIR variable in case you prefer to save the apkovls
# in a normal directory instead of mounting an external media.
# LBU_BACKUPDIR=/root/config-backups
 
# Uncomment below to let lbu make up to 3 backups
# BACKUP_LIMIT=3</pre>
 
Remember to set a root password, by default Alpine Linux's root account is passwordless.
{{cmd|passwd root}}
 
== Backup apkprov ==
It's a good idea to back up your apk provision file. You can pull it off your router to your local workstation with:
 
{{cmd|scp -r root@192.168.2.1:/media/mmcblk0p1/<YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc ./}}
 
And decrypt it with:
{{cmd|openssl enc -d -aes-256-cbc -in <YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc -out <YOUR HOST NAME>.apkovl.tar.gz}}
 
It can be encrypted with:
{{cmd|openssl aes-256-cbc -salt -in <YOUR HOST NAME>.apkovl.tar.gz -out <YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc}}
 
== Harden SSH ==
 
=== Generate a SSH key ===
{{cmd|ssh-keygen -t rsa -b 4096}}
 
You will want to put the contents of id_rsa.pub in /etc/ssh/authorized_keys
 
You can put multiple public keys on multiple lines if more than one person has access to the router.
 
=== /etc/ssh/sshd_config ===
A couple of good options to set in here can be:
 
<pre>ListenAddress 192.168.1.1
ListenAddress 192.168.2.1</pre>
 
While this isn't usually a good idea, a router doesn't need more than one user.
<pre>PermitRootLogin yes</pre>
 
The most important options:
<pre>RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile  /etc/ssh/authorized_keys
PasswordAuthentication no
PermitEmptyPasswords no
AllowTcpForwarding no
X11Forwarding no</pre>
 
=== /etc/conf.d/sshd ===
You will want to add <pre>rc_need="net"</pre>
 
This instructs OpenRC to make sure the network is up before starting ssh.
 
Finally add sshd to the default run level
{{cmd|rc-update add sshd default}}


= References =
[[category: VPN]]
* https://wiki.gentoo.org/wiki/Home_Router
[[category: Raspberry]]
* https://help.ubuntu.com/community/ADSLPPPoE
* https://wiki.archlinux.org/index.php/Router
* https://wiki.gentoo.org/wiki/IPv6_router_guide
* [https://vk5tu.livejournal.com/37206.html IPv6 at home, under the hood with Debian Wheezy and Internode]
* [http://vk5tu.livejournal.com/43059.html Raspberry Pi random number generator]
* [https://www.raspberrypi.org/forums/viewtopic.php?f=56&t=60569 rng-tools post by ktb]

Revision as of 10:03, 25 February 2020

Rationale

This guide demonstrates how to set up a Linux router with a VPN tunnel. You will need a second ethernet adapter. If you are using a Raspberry Pi like I did, then you can use something like this Apple USB Ethernet Adapter as it contains a ASIX AX88772 which has good Linux support.

You may choose to also buy an RTC clock. If you don't have an RTC clock, the time is lost when your Pi is shut down. When it is rebooted, the time will be set back to Thursday, 1 January 1970. As this is earlier than the creation time of your VPN certificates OpenVPN will refuse to start, which may mean you cannot do DNS lookups over VPN.

For wireless, a separate access point was purchased (Ubiquiti UniFi AP) because it contains a Atheros AR9287 which is supported by ath9k.

I only chose a Raspberry Pi due to the fact it was inexpensive. My WAN link is pathetic so I was not concerned with getting high PPS (Packets Per Second). You could choose to use an old x86/amd64 system instead. If I had better internet I'd probably go with an offering from Soekris such as the net6501 as it would have a much lower power consumption than a generic x86_64 desktop processor.

If you want to route speeds above 100 Mbit/s you'll want to make use of hardware encryption like AES-NI. The Soekris offerings have the option of an additional hardware encryption module (vpn1411). Another option is to use a Mini ITX motherboard, with a managed switch. I chose the Ubiquiti ES-16-150W.

If you wish to use IPv6 you should consider looking at Linux Router with VPN on a Raspberry Pi (IPv6) as the implementation does differ slightly to this tutorial.

The network in this tutorial looks like this:

Network Diagram Single IPv4
Network Diagram Single IPv4

Installation

This guide assumes you're using Alpine Linux from a micro SD card in ramdisk mode. It assumes you've read the basics of how to use Alpine local backup. The Raspberry Pi article contains information on how to install Alpine Linux on a Raspberry Pi.

Modem in full bridge mode

This particular page uses an example where you have a modem that uses PPPoE. You will need to modify parts which do not apply to you.

In this example I have a modem which has been configured in full bridge mode. PPP sessions are initiated on the router.

The modem I am using is a Cisco 877 Integrated Services Router. It has no web interface and is controlled over SSH. More information can be found Configuring a Cisco 877 in full bridge mode.

Network

/etc/hostname

Set this to your hostname eg: 

<HOST_NAME>

/etc/hosts

Set your host and hostname 

127.0.0.1	<HOST_NAME> <HOST_NAME>.<DOMAIN_NAME>

::1		<HOST_NAME> ipv6-gateway ipv6-loopback
ff00::0		ipv6-localnet
ff00::0		ipv6-mcastprefix
ff02::1		ipv6-allnodes
ff02::2		ipv6-allrouters
ff02::3		ipv6-allhosts

/etc/network/interfaces

Configure your network interfaces. Change "yourISP" to the file name of the file in /etc/ppp/peers/yourISP 

#
# Network Interfaces
#

# Loopback interfaces
auto lo
iface lo inet loopback
  address 127.0.0.1
  netmask 255.0.0.0

# Internal Interface - facing LAN
auto eth0
iface eth0 inet static
  address 192.168.1.1
  netmask 255.255.255.0
  broadcast 192.168.1.255


PPP

Next up we need to configure our router to be able to dial a PPP connection with our modem.

If your ISP uses PPP you may need to configure it. See PPP.

You will want to make sure you set your WAN interface, in this example we used eth1. 

# External Interface - facing Modem
allow-hotplug eth1
auto eth1
iface eth1 inet static
  address 192.168.0.2
  netmask 255.255.255.252
  broadcast 192.168.0.3
  pre-up /sbin/ip link set eth1 up
  up ifup ppp0=yourISP
  down ifdown ppp0=yourISP
  post-down /sbin/ip link set eth1 up

# Link to ISP
iface yourISP inet ppp
  provider yourISP

IPoE

Alternatively it's quite common for ISPs to use IPoE. IPoE is much simpler and only runs DHCP on the external interface. It should look something like: 

# External interface to ISP
allow-hotplug eth1
auto eth1
iface eth1 inet dhcp

iface eth1 inet static
    address 192.168.0.2
    netmask 255.255.255.252
    broadcast 192.168.0.3

iface eth1 inet6 manual

DHCP from ISP

Above we set DHCP and we set a static IP. The purpose of this is so we can still forward packets through to the modem to be able to access the web interface or ssh.

We do still need DHCP to get an IP address form our ISP though. I like to use dhcpcd instead of udhcp (the default in Alpine Linux), because it allows for Prefix Delegation, which is used in IPv6 networks.

My /etc/dhcpcd.conf looks like this: 

# Enable extra debugging
# debug
# logfile /var/log/dhcpcd.log

# Allow users of this group to interact with dhcpcd via the control
# socket.
#controlgroup wheel

# Inform the DHCP server of our hostname for DDNS.
hostname gateway

# Use the hardware address of the interface for the Client ID.
# clientid
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as
# per RFC4361. Some non-RFC compliant DHCP servers do not reply with
# this set. In this case, comment out duid and enable clientid above.
duid

# Persist interface configuration when dhcpcd exits.
persistent

# Rapid commit support.
# Safe to enable by default because it requires the equivalent option
# set on the server to actually work.
option rapid_commit

# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes

# Most distributions have NTP support.
option ntp_servers

# Respect the network MTU.
# Some interface drivers reset when changing the MTU so disabled by
# default.
#option interface_mtu 1586

# A ServerID is required by RFC2131.
require dhcp_server_identifier

# Generate Stable Private IPv6 Addresses instead of hardware based
# ones
slaac private

# A hook script is provided to lookup the hostname if not set by the
# DHCP server, but it should not be run by default.
nohook lookup-hostname

# Disable solicitations on all interfaces
noipv6rs

# Wait for IP before forking to background
waitip 6

# Don't touch DNS
nohook resolv.conf

allowinterfaces eth1 eth0.2
# Use the interface connected to WAN
interface eth1
    waitip 4
    noipv4ll
    ipv6rs # enable routing solicitation get the default IPv6 route
    iaid 1
    ia_pd 1/::/56 eth0.2/2/64
    timeout 30

interface eth0.2
    ipv6only

Basic IPtables firewall with routing

This demonstrates how to set up basic routing with a permissive outgoing firewall. Incoming packets are blocked. The rest is commented in the rule set.

First install iptables:

apk add iptables ip6tables

#########################################################################
# Basic iptables IPv4 routing rule set
#
# 192.168.1.0/24 routed directly to PPP0 via NAT
# 
#########################################################################

#
# Mangle Table
# We leave this empty for the moment.
#
*mangle
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
COMMIT

#
# Filter Table
# This is where we decide to ACCEPT, DROP or REJECT things
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
*filter

# Create rule chain per input interface for forwarding packets
:FWD_ETH0 - [0:0]
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]

# Create rule chain per input interface for input packets (for host itself)
:IN_ETH0 - [0:0]
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]

# Create a log drop chain
:LOG_DROP - [0:0]

# Pass input packet to corresponding rule chain
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0

# Pass forwarded packet to corresponding rule chain
-A FORWARD -i eth0 -j FWD_ETH0
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0

# Forward LAN traffic out
-A FWD_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Forward SSH packets from network to modem
-A FWD_ETH1 -s 192.168.0.0/30 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Forward HTTP to modem's webserver
-A FWD_ETH1 -s 192.168.0.0/30 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Forward traffic to ISP
-A FWD_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

# SSH to Router
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# DNS to Router
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# FreeRadius Client (eg a UniFi AP)
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# NTP to Router
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Accept traffic
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# SSH To Modem from Router
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# HTTP to modem
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Accept incoming tracked PPP0 connection
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
COMMIT

#
# NAT Table
# This is where translation of packets happens and "forwarding" of ports
# to specific hosts.
#
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]

# Port forwarding for Bittorrent
-A PREROUTING -i ppp0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.1.20
-A PREROUTING -i ppp0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.1.20

# Allows routing to our modem subnet so we can access the web interface or SSH
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 22 -j MASQUERADE
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE

# Allows hosts of the network to use the PPP tunnel
-A POSTROUTING -s 192.168.1.0/24 -o ppp0 -j MASQUERADE
COMMIT

I'd also highly suggest reading these resources if you are new to iptables:

/etc/sysctl.d/local.conf

# Controls IP packet forwarding
net.ipv4.ip_forward = 1

# Needed to use fwmark, only required if you want to set up the VPN subnet later in this article
net.ipv4.conf.all.rp_filter = 2

# Disable IPv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

Note IPv6 is disabled here if you want that see the other tutorial Linux Router with VPN on a Raspberry Pi (IPv6). You may also wish to look at ip-sysctl.txt to read about the other keys.

DHCP

apk add dhcp

/etc/conf.d/dhcpd

Specify the configuration file location, interface to run on and that you want DHCPD to run in IPv4 mode. 

# /etc/conf.d/dhcpd: config file for /etc/init.d/dhcpd

# If you require more than one instance of dhcpd you can create symbolic
# links to dhcpd service like so
#   cd /etc/init.d
#   ln -s dhcpd dhcpd.foo
#   cd ../conf.d
#   cp dhcpd dhcpd.foo
# Now you can edit dhcpd.foo and specify a different configuration file.
# You'll also need to specify a pidfile in that dhcpd.conf file.
# See the pid-file-name option in the dhcpd.conf man page for details.

# If you wish to run dhcpd in a chroot, uncomment the following line
# DHCPD_CHROOT="/var/lib/dhcp/chroot"

# All file paths below are relative to the chroot.
# You can specify a different chroot directory but MAKE SURE it's empty.

# Specify a configuration file - the default is /etc/dhcp/dhcpd.conf
DHCPD_CONF="/etc/dhcp/dhcpd.conf"

# Configure which interface or interfaces to for dhcpd to listen on.
# List all interfaces space separated. If this is not specified then
# we listen on all interfaces.
DHCPD_IFACE="eth0"

# Insert any other dhcpd options - see the man page for a full list.
DHCPD_OPTS="-4"

/etc/dhcp/dhcpd.conf

Configure your DHCP configuration server. For my DHCP server I'm going to have three subnets. Each has a specific purpose. You may choose to have any number of subnets like below. The broadcast-address would be different if you used VLANs. However in this case we are not. 

authoritative;
ddns-update-style interim;

shared-network home {
  subnet 192.168.1.0 netmask 255.255.255.0 {
    range 192.168.1.10 192.168.1.240;
    option subnet-mask 255.255.255.0;
    option broadcast-address 192.168.1.255;
    option routers 192.168.1.1;
    option ntp-servers 192.168.1.1;
    option domain-name-servers 192.168.1.1;
    allow unknown-clients;
  }

  subnet 192.168.2.0 netmask 255.255.255.0 {
    range 192.168.2.10 192.168.2.240;
    option subnet-mask 255.255.255.0;
    option broadcast-address 192.168.2.255;
    option routers 192.168.2.1;
    option ntp-servers 192.168.2.1;
    option domain-name-servers 192.168.1.1;
    ignore unknown-clients;
  }

  subnet 192.168.3.0 netmask 255.255.255.0 {
    range 192.168.3.10 192.168.3.240;
    option subnet-mask 255.255.255.0;
    option broadcast-address 192.168.3.255;
    option routers 192.168.3.1;
    option ntp-servers 192.168.3.1;
    option domain-name-servers 192.168.1.1;
    ignore unknown-clients;
  }
}

host Gaming_Computer {
  hardware ethernet 00:53:00:FF:FF:11;
  fixed-address 192.168.1.20;
  option subnet-mask 255.255.255.0;
  option broadcast-address 192.168.1.255;
  option routers 192.168.1.1;
  option host-name "gaming_computer";
}

host Linux_Workstation {
  hardware ethernet 00:53:00:FF:FF:22;
  fixed-address 192.168.2.21;
  option subnet-mask 255.255.255.0;
  option broadcast-address 192.168.2.255;
  option routers 192.168.2.1;
  option host-name "linux_workstation";
}

host printer {
  hardware ethernet 00:53:00:FF:FF:33;
  fixed-address 192.168.3.9;
  option subnet-mask 255.255.255.0;
  option broadcast-address 192.168.3.255;
  option routers 192.168.3.1;
}

Make sure to add this to the default run level once configured:

rc-update add dhcpd default

Synchronizing the clock

You can choose to use BusyBox's ntpd or you can choose a more fully fledged option like OpenNTPD or Chrony

Busybox /etc/conf.d/ntpd

Allow clients to synchronize their clocks with the router. 

# By default ntpd runs as a client. Add -l to run as a server on port 123.
NTPD_OPTS="-l -N -p <REMOTE TIME SERVER>"

Make sure to add this to the default run level once configured:

rc-update add ntpd default

Or if you prefer to synchronize with multiple servers...

Chrony /etc/chrony.conf

apk add chrony

logdir /var/log/chrony
log measurements statistics tracking

allow 192.168.0.0/30
allow 192.168.1.0/24
allow 192.168.2.0/24
allow 192.168.3.0/24
allow 192.168.4.0/24
broadcast 30 192.168.0.3
broadcast 30 192.168.1.255
broadcast 30 192.168.2.255
broadcast 30 192.168.3.255
broadcast 30 192.168.4.255

server 0.pool.ntp.org iburst
server 1.pool.ntp.org iburst
server 2.pool.ntp.org iburst
server 3.pool.ntp.org iburst

initstepslew 10 pool.ntp.org
driftfile /var/lib/chrony/chrony.drift
hwclockfile /etc/adjtime
rtcdevice /dev/rtc0
rtcsync

OpenNTPD /etc/ntpd.conf

Install OpenNTPD

apk add openntpd

Add to default run level.

rc-update add openntpd default

/etc/ntpd.conf

# sample ntpd configuration file, see ntpd.conf(5)

# Addresses to listen on (ntpd does not listen by default)
listen on 192.168.1.1
listen on 192.168.2.1

# sync to a single server
#server ntp.example.org

# use a random selection of NTP Pool Time Servers
# see http://support.ntp.org/bin/view/Servers/NTPPoolServers
server 0.pool.ntp.org
server 1.pool.ntp.org
server 2.pool.ntp.org
server 3.pool.ntp.org

tlsdate

The time can also be extracted from a https handshake. If the certificate is self-signed you will need to use skip-verification:

apk add tlsdate

tlsdate -V --skip-verification -p 80 -H example.com

timezone

You might also want to set a timezone, see Setting the timezone.

Saving Time

There are two ways to do this. If you didn't buy an RTC clock see Saving time with Software Clock. If you did like the PiFace Real Time Clock see Saving time with Hardware Clock

Unbound DNS forwarder with dnscrypt

We want to be able to do our lookups using dnscrypt without installing DNSCrypt on every client on the network. DNSCrypt can use it's own protocol or DNS over HTTPS.

The router will also run a DNS forwarder and request unknown domains over DNSCrypt for our clients. Borrowed from the ArchLinux wiki article on dnscrypt-proxy.

Unbound

First install

apk add unbound

/etc/unbound/unbound.conf

server:
    # Use this to include other text into the file.
    include: "/etc/unbound/filter.conf"

    # verbosity number, 0 is least verbose. 1 is default.
    verbosity: 1

    # specify the interfaces to answer queries from by ip-address.
    # The default is to listen to localhost (127.0.0.1 and ::1).
    # specify 0.0.0.0 and ::0 to bind to all available interfaces.
    # specify every interface[@port] on a new 'interface:' labelled line.
    # The listen interfaces are not changed on reload, only on restart.
    interface: 192.168.2.1
    interface: 192.168.3.1

    # Enable IPv4, "yes" or "no".
    do-ip4: yes

    # Enable IPv6, "yes" or "no".
    do-ip6: yes

    # Enable UDP, "yes" or "no".
    do-udp: yes

    # Enable TCP, "yes" or "no".
    do-tcp: yes

    # control which clients are allowed to make (recursive) queries
    # to this server. Specify classless netblocks with /size and action.
    # By default everything is refused, except for localhost.
    # Choose deny (drop message), refuse (polite error reply),
    # allow (recursive ok), allow_setrd (recursive ok, rd bit is forced on),
    # allow_snoop (recursive and nonrecursive ok)
    # deny_non_local (drop queries unless can be answered from local-data)
    # refuse_non_local (like deny_non_local but polite error reply).
    # access-control: 0.0.0.0/0 refuse
    # access-control: 127.0.0.0/8 allow
    # access-control: ::0/0 refuse
    # access-control: ::1 allow
    # access-control: ::ffff:127.0.0.1 allow
    access-control: 192.168.1.0/24 allow
    access-control: 192.168.2.0/24 allow
    access-control: 192.168.3.0/24 allow

    # the log file, "" means log to stderr.
    # Use of this option sets use-syslog to "no".
    logfile: "/var/log/unbound/unbound.log"

    # Log to syslog(3) if yes. The log facility LOG_DAEMON is used to
    # log to. If yes, it overrides the logfile.
    use-syslog: no

    # print one line with time, IP, name, type, class for every query.
    # log-queries: no

    # print one line per reply, with time, IP, name, type, class, rcode,
    # timetoresolve, fromcache and responsesize.
    # log-replies: no

    # enable to not answer id.server and hostname.bind queries.
    hide-identity: yes

    # enable to not answer version.server and version.bind queries.
    # hide-version: yes

    # enable to not answer trustanchor.unbound queries.
    hide-trustanchor: yes


    # Harden against very small EDNS buffer sizes.
    harden-short-bufsize: yes

    # Harden against unseemly large queries.
    harden-large-queries: yes

    # Harden against out of zone rrsets, to avoid spoofing attempts.
    harden-glue: yes

    # Harden against receiving dnssec-stripped data. If you turn it
    # off, failing to validate dnskey data for a trustanchor will
    # trigger insecure mode for that zone (like without a trustanchor).
    # Default on, which insists on dnssec data for trust-anchored zones.
    harden-dnssec-stripped: yes

    # Harden against queries that fall under dnssec-signed nxdomain names.
    harden-below-nxdomain: yes

    # Harden the referral path by performing additional queries for
    # infrastructure data.  Validates the replies (if possible).
    # Default off, because the lookups burden the server.  Experimental
    # implementation of draft-wijngaards-dnsext-resolver-side-mitigation.
    # harden-referral-path: no

    # Harden against algorithm downgrade when multiple algorithms are
    # advertised in the DS record.  If no, allows the weakest algorithm
    # to validate the zone.
    harden-algo-downgrade: yes

    # Use 0x20-encoded random bits in the query to foil spoof attempts.
    # This feature is an experimental implementation of draft dns-0x20.
    use-caps-for-id: yes

    # Allow the domain (and its subdomains) to contain private addresses.
    # local-data statements are allowed to contain private addresses too.
    private-domain: "<HOSTNAME>"

    # if yes, the above default do-not-query-address entries are present.
    # if no, localhost can be queried (for testing and debugging).
    do-not-query-localhost: no

    # File with trusted keys, kept uptodate using RFC5011 probes,
    # initial file like trust-anchor-file, then it stores metadata.
    # Use several entries, one per domain name, to track multiple zones.
    #
    # If you want to perform DNSSEC validation, run unbound-anchor before
    # you start unbound (i.e. in the system boot scripts).  And enable:
    # Please note usage of unbound-anchor root anchor is at your own risk
    # and under the terms of our LICENSE (see that file in the source).
    # auto-trust-anchor-file: "@UNBOUND_ROOTKEY_FILE@"
    auto-trust-anchor-file: "/etc/unbound/root.key"

    # If unbound is running service for the local host then it is useful
    # to perform lan-wide lookups to the upstream, and unblock the
    # long list of local-zones above.  If this unbound is a dns server
    # for a network of computers, disabled is better and stops information
    # leakage of local lan information.
    unblock-lan-zones: no

    # If you configure local-data without specifying local-zone, by
    # default a transparent local-zone is created for the data.
    #
    # You can add locally served data with
    # local-zone: "local." static
    # local-data: "mycomputer.local. IN A 192.0.2.51"
    # local-data: 'mytext.local TXT "content of text record"'

    # request upstream over TLS (with plain DNS inside the TLS stream).
    # Default is no.  Can be turned on and off with unbound-control.
    # tls-upstream: no

    # Forward zones
    # Create entries like below, to make all queries for 'example.com' and
    # 'example.org' go to the given list of servers. These servers have to handle
    # recursion to other nameservers. List zero or more nameservers by hostname
    # or by ipaddress. Use an entry with name "." to forward all queries.
    # If you enable forward-first, it attempts without the forward if it fails.
    # forward-zone:
    #    name: "example.com"
    #    forward-addr: 192.0.2.68
    #    forward-addr: 192.0.2.73@5355  # forward to port 5355.
    #    forward-first: no
    #    forward-tls-upstream: no
    #    forward-no-cache: no
    # forward-zone:
    #    name: "example.org"
    #    forward-host: fwd.example.com

forward-zone:
    name: "."
    forward-addr: 172.16.32.1@53
    forward-addr: ::1@53000
    forward-addr: 127.0.0.1@53000

Blocking Microsoft Telemetry on the network by domain

Microsoft has added telemetry analytics to Windows which you may want to block at a network level. More information about that can be found here.

This script takes in a list of domains and produces a filter file. We are directing all lookups to "0.0.0.1" which is an invalid IP and should fail immediately, unlike localhost. There are lists of the addresses in various places such as the tools people use to do this locally on Windows, ie Destroy-Windows-10-Spying, DisableWinTracking, Debloat-Windows-10 and Dominator.Windows10. I have prepared the list further down: Linux Router with VPN on a Raspberry Pi#/etc/unbound/filter.conf.

You could also use this to block advertising, but that's probably easier to do in a web browser with something like uBlock Origin.

Another way is to disable this stuff with a group policy see Manage connections from Windows operating system components to Microsoft services only for Windows 10 Enterprise, version 1607 and newer and Windows Server 2016.

/etc/unbound/unbound.conf

In your main unbound configuration add 

include: /etc/unbound/filter.conf

Script to prepare/sort domains for Unbound

#!/bin/sh

##################################################
# Script taken from http://npr.me.uk/unbound.html
# Note you need GNU sed
##################################################

# Remove "#" comments
# Remove space and tab
# Remove blank lines
# Remove localhost and broadcasthost lines
# Keep just the hosts
# Remove leading and trailing space and tab (again)
# Make everything lower case

sed -e "s/#.*//" \
    -e "s/[ \x09]*$//"\
    -e "/^$/ d" \
    -e "/^.*local.*/ d" \
    -e "/^.*broadcasthost.*/ d" \
    -e "s/\(^.*\) \([a-zA-Z0-9\.\-]*\)/\2/" \
    -e "s/^[ \x09]*//;s/[ \x09]*$//" $1 \
    -e "s/\(.*\)/\L\1/" hosts.txt > temp1.txt

# Remove any duplicate hosts

sort temp1.txt | uniq >temp2.txt

# Remove any hosts starting with "."
# Create the two required lines for each host.

sed -e "/^\..*/ d" \
    -e "s/\(^.*\)/local-zone: \x22\1\x22 redirect\nlocal-data: \x22\1 A 0.0.0.1\x22/" \
       temp2.txt > filter.conf

# Clean up
rm temp1.txt
rm temp2.txt

/etc/unbound/filter.conf

local-zone: "a-0001.a-msedge.net" redirect
local-data: "a-0001.a-msedge.net A 0.0.0.1"
local-zone: "a-0001.dc-msedge.net" redirect
local-data: "a-0001.dc-msedge.net A 0.0.0.1"
local-zone: "a-0002.a-msedge.net" redirect
local-data: "a-0002.a-msedge.net A 0.0.0.1"
local-zone: "a-0003.a-msedge.net" redirect
local-data: "a-0003.a-msedge.net A 0.0.0.1"
local-zone: "a-0004.a-msedge.net" redirect
local-data: "a-0004.a-msedge.net A 0.0.0.1"
local-zone: "a-0005.a-msedge.net" redirect
local-data: "a-0005.a-msedge.net A 0.0.0.1"
local-zone: "a-0006.a-msedge.net" redirect
local-data: "a-0006.a-msedge.net A 0.0.0.1"
local-zone: "a-0007.a-msedge.net" redirect
local-data: "a-0007.a-msedge.net A 0.0.0.1"
local-zone: "a-0008.a-msedge.net" redirect
local-data: "a-0008.a-msedge.net A 0.0.0.1"
local-zone: "a-0009.a-msedge.net" redirect
local-data: "a-0009.a-msedge.net A 0.0.0.1"
local-zone: "a-0010.a-msedge.net" redirect
local-data: "a-0010.a-msedge.net A 0.0.0.1"
local-zone: "a-0011.a-msedge.net" redirect
local-data: "a-0011.a-msedge.net A 0.0.0.1"
local-zone: "a-0012.a-msedge.net" redirect
local-data: "a-0012.a-msedge.net A 0.0.0.1"
local-zone: "a.ads1.msn.com" redirect
local-data: "a.ads1.msn.com A 0.0.0.1"
local-zone: "a.ads2.msads.net" redirect
local-data: "a.ads2.msads.net A 0.0.0.1"
local-zone: "a.ads2.msn.com" redirect
local-data: "a.ads2.msn.com A 0.0.0.1"
local-zone: "ac3.msn.com" redirect
local-data: "ac3.msn.com A 0.0.0.1"
local-zone: "activity.windows.com" redirect
local-data: "activity.windows.com A 0.0.0.1"
local-zone: "adnexus.net" redirect
local-data: "adnexus.net A 0.0.0.1"
local-zone: "adnxs.com" redirect
local-data: "adnxs.com A 0.0.0.1"
local-zone: "ads1.msads.net" redirect
local-data: "ads1.msads.net A 0.0.0.1"
local-zone: "ads1.msn.com" redirect
local-data: "ads1.msn.com A 0.0.0.1"
local-zone: "ads.msn.com" redirect
local-data: "ads.msn.com A 0.0.0.1"
local-zone: "aidps.atdmt.com" redirect
local-data: "aidps.atdmt.com A 0.0.0.1"
local-zone: "aka-cdn-ns.adtech.de" redirect
local-data: "aka-cdn-ns.adtech.de A 0.0.0.1"
local-zone: "a-msedge.net" redirect
local-data: "a-msedge.net A 0.0.0.1"
local-zone: "a.rad.msn.com" redirect
local-data: "a.rad.msn.com A 0.0.0.1"
local-zone: "array101-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array101-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array102-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array102-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array103-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array103-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array104-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array104-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array201-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array201-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array202-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array202-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array203-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array203-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array204-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array204-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array401-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array401-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array402-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array402-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array403-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array403-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array404-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array404-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array405-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array405-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array406-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array406-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array407-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array407-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "array408-prod.do.dsp.mp.microsoft.com" redirect
local-data: "array408-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "ars.smartscreen.microsoft.com" redirect
local-data: "ars.smartscreen.microsoft.com A 0.0.0.1"
local-zone: "az361816.vo.msecnd.net" redirect
local-data: "az361816.vo.msecnd.net A 0.0.0.1"
local-zone: "az512334.vo.msecnd.net" redirect
local-data: "az512334.vo.msecnd.net A 0.0.0.1"
local-zone: "b.ads1.msn.com" redirect
local-data: "b.ads1.msn.com A 0.0.0.1"
local-zone: "b.ads2.msads.net" redirect
local-data: "b.ads2.msads.net A 0.0.0.1"
local-zone: "bingads.microsoft.com" redirect
local-data: "bingads.microsoft.com A 0.0.0.1"
local-zone: "bl3301-a.1drv.com" redirect
local-data: "bl3301-a.1drv.com A 0.0.0.1"
local-zone: "bl3301-c.1drv.com" redirect
local-data: "bl3301-c.1drv.com A 0.0.0.1"
local-zone: "bl3301-g.1drv.com" redirect
local-data: "bl3301-g.1drv.com A 0.0.0.1"
local-zone: "blob.weather.microsoft.com" redirect
local-data: "blob.weather.microsoft.com A 0.0.0.1"
local-zone: "bn1304-e.1drv.com" redirect
local-data: "bn1304-e.1drv.com A 0.0.0.1"
local-zone: "bn1306-a.1drv.com" redirect
local-data: "bn1306-a.1drv.com A 0.0.0.1"
local-zone: "bn1306-e.1drv.com" redirect
local-data: "bn1306-e.1drv.com A 0.0.0.1"
local-zone: "bn1306-g.1drv.com" redirect
local-data: "bn1306-g.1drv.com A 0.0.0.1"
local-zone: "bn2b-cor001.api.p001.1drv.com" redirect
local-data: "bn2b-cor001.api.p001.1drv.com A 0.0.0.1"
local-zone: "bn2b-cor002.api.p001.1drv.com" redirect
local-data: "bn2b-cor002.api.p001.1drv.com A 0.0.0.1"
local-zone: "bn2b-cor003.api.p001.1drv.com" redirect
local-data: "bn2b-cor003.api.p001.1drv.com A 0.0.0.1"
local-zone: "bn2b-cor004.api.p001.1drv.com" redirect
local-data: "bn2b-cor004.api.p001.1drv.com A 0.0.0.1"
local-zone: "bn2wns1.wns.windows.com" redirect
local-data: "bn2wns1.wns.windows.com A 0.0.0.1"
local-zone: "bn3p-cor001.api.p001.1drv.com" redirect
local-data: "bn3p-cor001.api.p001.1drv.com A 0.0.0.1"
local-zone: "bn3sch020022328.wns.windows.com" redirect
local-data: "bn3sch020022328.wns.windows.com A 0.0.0.1"
local-zone: "b.rad.msn.com" redirect
local-data: "b.rad.msn.com A 0.0.0.1"
local-zone: "bs.serving-sys.com" redirect
local-data: "bs.serving-sys.com A 0.0.0.1"
local-zone: "by3301-a.1drv.com" redirect
local-data: "by3301-a.1drv.com A 0.0.0.1"
local-zone: "by3301-c.1drv.com" redirect
local-data: "by3301-c.1drv.com A 0.0.0.1"
local-zone: "by3301-e.1drv.com" redirect
local-data: "by3301-e.1drv.com A 0.0.0.1"
local-zone: "c-0001.dc-msedge.net" redirect
local-data: "c-0001.dc-msedge.net A 0.0.0.1"
local-zone: "cache.datamart.windows.com" redirect
local-data: "cache.datamart.windows.com A 0.0.0.1"
local-zone: "candycrushsoda.king.com" redirect
local-data: "candycrushsoda.king.com A 0.0.0.1"
local-zone: "c.atdmt.com" redirect
local-data: "c.atdmt.com A 0.0.0.1"
local-zone: "ca.telemetry.microsoft.com" redirect
local-data: "ca.telemetry.microsoft.com A 0.0.0.1"
local-zone: "cdn.atdmt.com" redirect
local-data: "cdn.atdmt.com A 0.0.0.1"
local-zone: "cdn.content.prod.cms.msn.com" redirect
local-data: "cdn.content.prod.cms.msn.com A 0.0.0.1"
local-zone: "cdn.onenote.net" redirect
local-data: "cdn.onenote.net A 0.0.0.1"
local-zone: "cds1204.lon.llnw.net" redirect
local-data: "cds1204.lon.llnw.net A 0.0.0.1"
local-zone: "cds1293.lon.llnw.net" redirect
local-data: "cds1293.lon.llnw.net A 0.0.0.1"
local-zone: "cds20417.lcy.llnw.net" redirect
local-data: "cds20417.lcy.llnw.net A 0.0.0.1"
local-zone: "cds20431.lcy.llnw.net" redirect
local-data: "cds20431.lcy.llnw.net A 0.0.0.1"
local-zone: "cds20450.lcy.llnw.net" redirect
local-data: "cds20450.lcy.llnw.net A 0.0.0.1"
local-zone: "cds20457.lcy.llnw.net" redirect
local-data: "cds20457.lcy.llnw.net A 0.0.0.1"
local-zone: "cds20475.lcy.llnw.net" redirect
local-data: "cds20475.lcy.llnw.net A 0.0.0.1"
local-zone: "cds21244.lon.llnw.net" redirect
local-data: "cds21244.lon.llnw.net A 0.0.0.1"
local-zone: "cds26.ams9.msecn.net" redirect
local-data: "cds26.ams9.msecn.net A 0.0.0.1"
local-zone: "cds425.lcy.llnw.net" redirect
local-data: "cds425.lcy.llnw.net A 0.0.0.1"
local-zone: "cds459.lcy.llnw.net" redirect
local-data: "cds459.lcy.llnw.net A 0.0.0.1"
local-zone: "cds494.lcy.llnw.net" redirect
local-data: "cds494.lcy.llnw.net A 0.0.0.1"
local-zone: "cds965.lon.llnw.net" redirect
local-data: "cds965.lon.llnw.net A 0.0.0.1"
local-zone: "ch1-cor001.api.p001.1drv.com" redirect
local-data: "ch1-cor001.api.p001.1drv.com A 0.0.0.1"
local-zone: "ch1-cor002.api.p001.1drv.com" redirect
local-data: "ch1-cor002.api.p001.1drv.com A 0.0.0.1"
local-zone: "ch3301-c.1drv.com" redirect
local-data: "ch3301-c.1drv.com A 0.0.0.1"
local-zone: "ch3301-e.1drv.com" redirect
local-data: "ch3301-e.1drv.com A 0.0.0.1"
local-zone: "ch3301-g.1drv.com" redirect
local-data: "ch3301-g.1drv.com A 0.0.0.1"
local-zone: "ch3302-c.1drv.com" redirect
local-data: "ch3302-c.1drv.com A 0.0.0.1"
local-zone: "ch3302-e.1drv.com" redirect
local-data: "ch3302-e.1drv.com A 0.0.0.1"
local-zone: "choice.microsoft.com" redirect
local-data: "choice.microsoft.com A 0.0.0.1"
local-zone: "choice.microsoft.com.nsatc.net" redirect
local-data: "choice.microsoft.com.nsatc.net A 0.0.0.1"
local-zone: "clientconfig.passport.net" redirect
local-data: "clientconfig.passport.net A 0.0.0.1"
local-zone: "client-s.gateway.messenger.live.com" redirect
local-data: "client-s.gateway.messenger.live.com A 0.0.0.1"
local-zone: "client.wns.windows.com" redirect
local-data: "client.wns.windows.com A 0.0.0.1"
local-zone: "c.msn.com" redirect
local-data: "c.msn.com A 0.0.0.1"
local-zone: "compatexchange1.trafficmanager.net" redirect
local-data: "compatexchange1.trafficmanager.net A 0.0.0.1"
local-zone: "compatexchange.cloudapp.net" redirect
local-data: "compatexchange.cloudapp.net A 0.0.0.1"
local-zone: "continuum.dds.microsoft.com" redirect
local-data: "continuum.dds.microsoft.com A 0.0.0.1"
local-zone: "corpext.msitadfs.glbdns2.microsoft.com" redirect
local-data: "corpext.msitadfs.glbdns2.microsoft.com A 0.0.0.1"
local-zone: "corp.sts.microsoft.com" redirect
local-data: "corp.sts.microsoft.com A 0.0.0.1"
local-zone: "cp101-prod.do.dsp.mp.microsoft.com" redirect
local-data: "cp101-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "cp201-prod.do.dsp.mp.microsoft.com" redirect
local-data: "cp201-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "cp401-prod.do.dsp.mp.microsoft.com" redirect
local-data: "cp401-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "cs1.wpc.v0cdn.net" redirect
local-data: "cs1.wpc.v0cdn.net A 0.0.0.1"
local-zone: "db3aqu.atdmt.com" redirect
local-data: "db3aqu.atdmt.com A 0.0.0.1"
local-zone: "db3wns2011111.wns.windows.com" redirect
local-data: "db3wns2011111.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101100122.wns.windows.com" redirect
local-data: "db5sch101100122.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101100127.wns.windows.com" redirect
local-data: "db5sch101100127.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101100831.wns.windows.com" redirect
local-data: "db5sch101100831.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101100835.wns.windows.com" redirect
local-data: "db5sch101100835.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101100917.wns.windows.com" redirect
local-data: "db5sch101100917.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101100925.wns.windows.com" redirect
local-data: "db5sch101100925.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101100928.wns.windows.com" redirect
local-data: "db5sch101100928.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101100938.wns.windows.com" redirect
local-data: "db5sch101100938.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101001.wns.windows.com" redirect
local-data: "db5sch101101001.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101022.wns.windows.com" redirect
local-data: "db5sch101101022.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101024.wns.windows.com" redirect
local-data: "db5sch101101024.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101031.wns.windows.com" redirect
local-data: "db5sch101101031.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101034.wns.windows.com" redirect
local-data: "db5sch101101034.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101042.wns.windows.com" redirect
local-data: "db5sch101101042.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101044.wns.windows.com" redirect
local-data: "db5sch101101044.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101122.wns.windows.com" redirect
local-data: "db5sch101101122.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101123.wns.windows.com" redirect
local-data: "db5sch101101123.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101125.wns.windows.com" redirect
local-data: "db5sch101101125.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101128.wns.windows.com" redirect
local-data: "db5sch101101128.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101129.wns.windows.com" redirect
local-data: "db5sch101101129.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101133.wns.windows.com" redirect
local-data: "db5sch101101133.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101145.wns.windows.com" redirect
local-data: "db5sch101101145.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101209.wns.windows.com" redirect
local-data: "db5sch101101209.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101221.wns.windows.com" redirect
local-data: "db5sch101101221.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101228.wns.windows.com" redirect
local-data: "db5sch101101228.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101231.wns.windows.com" redirect
local-data: "db5sch101101231.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101237.wns.windows.com" redirect
local-data: "db5sch101101237.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101317.wns.windows.com" redirect
local-data: "db5sch101101317.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101324.wns.windows.com" redirect
local-data: "db5sch101101324.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101329.wns.windows.com" redirect
local-data: "db5sch101101329.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101333.wns.windows.com" redirect
local-data: "db5sch101101333.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101334.wns.windows.com" redirect
local-data: "db5sch101101334.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101338.wns.windows.com" redirect
local-data: "db5sch101101338.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101419.wns.windows.com" redirect
local-data: "db5sch101101419.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101424.wns.windows.com" redirect
local-data: "db5sch101101424.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101426.wns.windows.com" redirect
local-data: "db5sch101101426.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101427.wns.windows.com" redirect
local-data: "db5sch101101427.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101430.wns.windows.com" redirect
local-data: "db5sch101101430.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101445.wns.windows.com" redirect
local-data: "db5sch101101445.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101511.wns.windows.com" redirect
local-data: "db5sch101101511.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101519.wns.windows.com" redirect
local-data: "db5sch101101519.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101529.wns.windows.com" redirect
local-data: "db5sch101101529.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101535.wns.windows.com" redirect
local-data: "db5sch101101535.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101541.wns.windows.com" redirect
local-data: "db5sch101101541.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101543.wns.windows.com" redirect
local-data: "db5sch101101543.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101608.wns.windows.com" redirect
local-data: "db5sch101101608.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101618.wns.windows.com" redirect
local-data: "db5sch101101618.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101629.wns.windows.com" redirect
local-data: "db5sch101101629.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101631.wns.windows.com" redirect
local-data: "db5sch101101631.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101633.wns.windows.com" redirect
local-data: "db5sch101101633.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101640.wns.windows.com" redirect
local-data: "db5sch101101640.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101711.wns.windows.com" redirect
local-data: "db5sch101101711.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101722.wns.windows.com" redirect
local-data: "db5sch101101722.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101739.wns.windows.com" redirect
local-data: "db5sch101101739.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101745.wns.windows.com" redirect
local-data: "db5sch101101745.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101813.wns.windows.com" redirect
local-data: "db5sch101101813.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101820.wns.windows.com" redirect
local-data: "db5sch101101820.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101826.wns.windows.com" redirect
local-data: "db5sch101101826.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101835.wns.windows.com" redirect
local-data: "db5sch101101835.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101837.wns.windows.com" redirect
local-data: "db5sch101101837.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101844.wns.windows.com" redirect
local-data: "db5sch101101844.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101907.wns.windows.com" redirect
local-data: "db5sch101101907.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101914.wns.windows.com" redirect
local-data: "db5sch101101914.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101929.wns.windows.com" redirect
local-data: "db5sch101101929.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101939.wns.windows.com" redirect
local-data: "db5sch101101939.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101101941.wns.windows.com" redirect
local-data: "db5sch101101941.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101102015.wns.windows.com" redirect
local-data: "db5sch101102015.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101102017.wns.windows.com" redirect
local-data: "db5sch101102017.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101102019.wns.windows.com" redirect
local-data: "db5sch101102019.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101102023.wns.windows.com" redirect
local-data: "db5sch101102023.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101102025.wns.windows.com" redirect
local-data: "db5sch101102025.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101102032.wns.windows.com" redirect
local-data: "db5sch101102032.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101102033.wns.windows.com" redirect
local-data: "db5sch101102033.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110108.wns.windows.com" redirect
local-data: "db5sch101110108.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110109.wns.windows.com" redirect
local-data: "db5sch101110109.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110114.wns.windows.com" redirect
local-data: "db5sch101110114.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110135.wns.windows.com" redirect
local-data: "db5sch101110135.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110142.wns.windows.com" redirect
local-data: "db5sch101110142.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110204.wns.windows.com" redirect
local-data: "db5sch101110204.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110206.wns.windows.com" redirect
local-data: "db5sch101110206.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110214.wns.windows.com" redirect
local-data: "db5sch101110214.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110225.wns.windows.com" redirect
local-data: "db5sch101110225.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110232.wns.windows.com" redirect
local-data: "db5sch101110232.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110245.wns.windows.com" redirect
local-data: "db5sch101110245.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110315.wns.windows.com" redirect
local-data: "db5sch101110315.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110323.wns.windows.com" redirect
local-data: "db5sch101110323.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110325.wns.windows.com" redirect
local-data: "db5sch101110325.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110328.wns.windows.com" redirect
local-data: "db5sch101110328.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110331.wns.windows.com" redirect
local-data: "db5sch101110331.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110341.wns.windows.com" redirect
local-data: "db5sch101110341.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110343.wns.windows.com" redirect
local-data: "db5sch101110343.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110345.wns.windows.com" redirect
local-data: "db5sch101110345.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110403.wns.windows.com" redirect
local-data: "db5sch101110403.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110419.wns.windows.com" redirect
local-data: "db5sch101110419.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110438.wns.windows.com" redirect
local-data: "db5sch101110438.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110442.wns.windows.com" redirect
local-data: "db5sch101110442.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110501.wns.windows.com" redirect
local-data: "db5sch101110501.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110527.wns.windows.com" redirect
local-data: "db5sch101110527.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110533.wns.windows.com" redirect
local-data: "db5sch101110533.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110618.wns.windows.com" redirect
local-data: "db5sch101110618.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110622.wns.windows.com" redirect
local-data: "db5sch101110622.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110624.wns.windows.com" redirect
local-data: "db5sch101110624.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110626.wns.windows.com" redirect
local-data: "db5sch101110626.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110634.wns.windows.com" redirect
local-data: "db5sch101110634.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110705.wns.windows.com" redirect
local-data: "db5sch101110705.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110724.wns.windows.com" redirect
local-data: "db5sch101110724.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110740.wns.windows.com" redirect
local-data: "db5sch101110740.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110810.wns.windows.com" redirect
local-data: "db5sch101110810.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110816.wns.windows.com" redirect
local-data: "db5sch101110816.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110821.wns.windows.com" redirect
local-data: "db5sch101110821.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110822.wns.windows.com" redirect
local-data: "db5sch101110822.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110825.wns.windows.com" redirect
local-data: "db5sch101110825.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110828.wns.windows.com" redirect
local-data: "db5sch101110828.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110835.wns.windows.com" redirect
local-data: "db5sch101110835.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110919.wns.windows.com" redirect
local-data: "db5sch101110919.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110921.wns.windows.com" redirect
local-data: "db5sch101110921.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110923.wns.windows.com" redirect
local-data: "db5sch101110923.wns.windows.com A 0.0.0.1"
local-zone: "db5sch101110929.wns.windows.com" redirect
local-data: "db5sch101110929.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103081814.wns.windows.com" redirect
local-data: "db5sch103081814.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082011.wns.windows.com" redirect
local-data: "db5sch103082011.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082111.wns.windows.com" redirect
local-data: "db5sch103082111.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082308.wns.windows.com" redirect
local-data: "db5sch103082308.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082406.wns.windows.com" redirect
local-data: "db5sch103082406.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082409.wns.windows.com" redirect
local-data: "db5sch103082409.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082609.wns.windows.com" redirect
local-data: "db5sch103082609.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082611.wns.windows.com" redirect
local-data: "db5sch103082611.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082709.wns.windows.com" redirect
local-data: "db5sch103082709.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082712.wns.windows.com" redirect
local-data: "db5sch103082712.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103082806.wns.windows.com" redirect
local-data: "db5sch103082806.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103090115.wns.windows.com" redirect
local-data: "db5sch103090115.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103090415.wns.windows.com" redirect
local-data: "db5sch103090415.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103090513.wns.windows.com" redirect
local-data: "db5sch103090513.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103090515.wns.windows.com" redirect
local-data: "db5sch103090515.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103090608.wns.windows.com" redirect
local-data: "db5sch103090608.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103090806.wns.windows.com" redirect
local-data: "db5sch103090806.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103090814.wns.windows.com" redirect
local-data: "db5sch103090814.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103090906.wns.windows.com" redirect
local-data: "db5sch103090906.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091011.wns.windows.com" redirect
local-data: "db5sch103091011.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091012.wns.windows.com" redirect
local-data: "db5sch103091012.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091106.wns.windows.com" redirect
local-data: "db5sch103091106.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091108.wns.windows.com" redirect
local-data: "db5sch103091108.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091212.wns.windows.com" redirect
local-data: "db5sch103091212.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091311.wns.windows.com" redirect
local-data: "db5sch103091311.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091414.wns.windows.com" redirect
local-data: "db5sch103091414.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091511.wns.windows.com" redirect
local-data: "db5sch103091511.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091617.wns.windows.com" redirect
local-data: "db5sch103091617.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091715.wns.windows.com" redirect
local-data: "db5sch103091715.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091817.wns.windows.com" redirect
local-data: "db5sch103091817.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091908.wns.windows.com" redirect
local-data: "db5sch103091908.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103091911.wns.windows.com" redirect
local-data: "db5sch103091911.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103092010.wns.windows.com" redirect
local-data: "db5sch103092010.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103092108.wns.windows.com" redirect
local-data: "db5sch103092108.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103092109.wns.windows.com" redirect
local-data: "db5sch103092109.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103092209.wns.windows.com" redirect
local-data: "db5sch103092209.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103092210.wns.windows.com" redirect
local-data: "db5sch103092210.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103092509.wns.windows.com" redirect
local-data: "db5sch103092509.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100117.wns.windows.com" redirect
local-data: "db5sch103100117.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100121.wns.windows.com" redirect
local-data: "db5sch103100121.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100221.wns.windows.com" redirect
local-data: "db5sch103100221.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100313.wns.windows.com" redirect
local-data: "db5sch103100313.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100314.wns.windows.com" redirect
local-data: "db5sch103100314.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100510.wns.windows.com" redirect
local-data: "db5sch103100510.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100511.wns.windows.com" redirect
local-data: "db5sch103100511.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100611.wns.windows.com" redirect
local-data: "db5sch103100611.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103100712.wns.windows.com" redirect
local-data: "db5sch103100712.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101105.wns.windows.com" redirect
local-data: "db5sch103101105.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101208.wns.windows.com" redirect
local-data: "db5sch103101208.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101212.wns.windows.com" redirect
local-data: "db5sch103101212.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101314.wns.windows.com" redirect
local-data: "db5sch103101314.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101411.wns.windows.com" redirect
local-data: "db5sch103101411.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101413.wns.windows.com" redirect
local-data: "db5sch103101413.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101513.wns.windows.com" redirect
local-data: "db5sch103101513.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101610.wns.windows.com" redirect
local-data: "db5sch103101610.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101611.wns.windows.com" redirect
local-data: "db5sch103101611.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101705.wns.windows.com" redirect
local-data: "db5sch103101705.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101711.wns.windows.com" redirect
local-data: "db5sch103101711.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101909.wns.windows.com" redirect
local-data: "db5sch103101909.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103101914.wns.windows.com" redirect
local-data: "db5sch103101914.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102009.wns.windows.com" redirect
local-data: "db5sch103102009.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102112.wns.windows.com" redirect
local-data: "db5sch103102112.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102203.wns.windows.com" redirect
local-data: "db5sch103102203.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102209.wns.windows.com" redirect
local-data: "db5sch103102209.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102310.wns.windows.com" redirect
local-data: "db5sch103102310.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102404.wns.windows.com" redirect
local-data: "db5sch103102404.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102609.wns.windows.com" redirect
local-data: "db5sch103102609.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102610.wns.windows.com" redirect
local-data: "db5sch103102610.wns.windows.com A 0.0.0.1"
local-zone: "db5sch103102805.wns.windows.com" redirect
local-data: "db5sch103102805.wns.windows.com A 0.0.0.1"
local-zone: "db5wns1d.wns.windows.com" redirect
local-data: "db5wns1d.wns.windows.com A 0.0.0.1"
local-zone: "db5.wns.windows.com" redirect
local-data: "db5.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090104.wns.windows.com" redirect
local-data: "db6sch102090104.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090112.wns.windows.com" redirect
local-data: "db6sch102090112.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090116.wns.windows.com" redirect
local-data: "db6sch102090116.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090122.wns.windows.com" redirect
local-data: "db6sch102090122.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090203.wns.windows.com" redirect
local-data: "db6sch102090203.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090206.wns.windows.com" redirect
local-data: "db6sch102090206.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090208.wns.windows.com" redirect
local-data: "db6sch102090208.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090209.wns.windows.com" redirect
local-data: "db6sch102090209.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090211.wns.windows.com" redirect
local-data: "db6sch102090211.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090305.wns.windows.com" redirect
local-data: "db6sch102090305.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090306.wns.windows.com" redirect
local-data: "db6sch102090306.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090308.wns.windows.com" redirect
local-data: "db6sch102090308.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090311.wns.windows.com" redirect
local-data: "db6sch102090311.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090313.wns.windows.com" redirect
local-data: "db6sch102090313.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090410.wns.windows.com" redirect
local-data: "db6sch102090410.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090412.wns.windows.com" redirect
local-data: "db6sch102090412.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090504.wns.windows.com" redirect
local-data: "db6sch102090504.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090510.wns.windows.com" redirect
local-data: "db6sch102090510.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090512.wns.windows.com" redirect
local-data: "db6sch102090512.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090513.wns.windows.com" redirect
local-data: "db6sch102090513.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090514.wns.windows.com" redirect
local-data: "db6sch102090514.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090519.wns.windows.com" redirect
local-data: "db6sch102090519.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090613.wns.windows.com" redirect
local-data: "db6sch102090613.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090619.wns.windows.com" redirect
local-data: "db6sch102090619.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090810.wns.windows.com" redirect
local-data: "db6sch102090810.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090811.wns.windows.com" redirect
local-data: "db6sch102090811.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090902.wns.windows.com" redirect
local-data: "db6sch102090902.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090905.wns.windows.com" redirect
local-data: "db6sch102090905.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090907.wns.windows.com" redirect
local-data: "db6sch102090907.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090908.wns.windows.com" redirect
local-data: "db6sch102090908.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090910.wns.windows.com" redirect
local-data: "db6sch102090910.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102090911.wns.windows.com" redirect
local-data: "db6sch102090911.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091003.wns.windows.com" redirect
local-data: "db6sch102091003.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091007.wns.windows.com" redirect
local-data: "db6sch102091007.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091008.wns.windows.com" redirect
local-data: "db6sch102091008.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091009.wns.windows.com" redirect
local-data: "db6sch102091009.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091011.wns.windows.com" redirect
local-data: "db6sch102091011.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091103.wns.windows.com" redirect
local-data: "db6sch102091103.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091105.wns.windows.com" redirect
local-data: "db6sch102091105.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091204.wns.windows.com" redirect
local-data: "db6sch102091204.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091209.wns.windows.com" redirect
local-data: "db6sch102091209.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091305.wns.windows.com" redirect
local-data: "db6sch102091305.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091307.wns.windows.com" redirect
local-data: "db6sch102091307.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091308.wns.windows.com" redirect
local-data: "db6sch102091308.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091309.wns.windows.com" redirect
local-data: "db6sch102091309.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091314.wns.windows.com" redirect
local-data: "db6sch102091314.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091412.wns.windows.com" redirect
local-data: "db6sch102091412.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091503.wns.windows.com" redirect
local-data: "db6sch102091503.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091507.wns.windows.com" redirect
local-data: "db6sch102091507.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091602.wns.windows.com" redirect
local-data: "db6sch102091602.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091603.wns.windows.com" redirect
local-data: "db6sch102091603.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091606.wns.windows.com" redirect
local-data: "db6sch102091606.wns.windows.com A 0.0.0.1"
local-zone: "db6sch102091607.wns.windows.com" redirect
local-data: "db6sch102091607.wns.windows.com A 0.0.0.1"
local-zone: "deploy.static.akamaitechnologies.com" redirect
local-data: "deploy.static.akamaitechnologies.com A 0.0.0.1"
local-zone: "device.auth.xboxlive.com" redirect
local-data: "device.auth.xboxlive.com A 0.0.0.1"
local-zone: "dev.virtualearth.net" redirect
local-data: "dev.virtualearth.net A 0.0.0.1"
local-zone: "df.telemetry.microsoft.com" redirect
local-data: "df.telemetry.microsoft.com A 0.0.0.1"
local-zone: "diagnostics.support.microsoft.com" redirect
local-data: "diagnostics.support.microsoft.com A 0.0.0.1"
local-zone: "disc101-prod.do.dsp.mp.microsoft.com" redirect
local-data: "disc101-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "disc201-prod.do.dsp.mp.microsoft.com" redirect
local-data: "disc201-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "disc401-prod.do.dsp.mp.microsoft.com" redirect
local-data: "disc401-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "dmd.metaservices.microsoft.com" redirect
local-data: "dmd.metaservices.microsoft.com A 0.0.0.1"
local-zone: "dns.msftncsi.com" redirect
local-data: "dns.msftncsi.com A 0.0.0.1"
local-zone: "ec.atdmt.com" redirect
local-data: "ec.atdmt.com A 0.0.0.1"
local-zone: "ecn.dev.virtualearth.net" redirect
local-data: "ecn.dev.virtualearth.net A 0.0.0.1"
local-zone: "eu.vortex.data.microsoft.com" redirect
local-data: "eu.vortex.data.microsoft.com A 0.0.0.1"
local-zone: "feedback.microsoft-hohm.com" redirect
local-data: "feedback.microsoft-hohm.com A 0.0.0.1"
local-zone: "feedback.search.microsoft.com" redirect
local-data: "feedback.search.microsoft.com A 0.0.0.1"
local-zone: "feedback.windows.com" redirect
local-data: "feedback.windows.com A 0.0.0.1"
local-zone: "flex.msn.com" redirect
local-data: "flex.msn.com A 0.0.0.1"
local-zone: "fs.microsoft.com" redirect
local-data: "fs.microsoft.com A 0.0.0.1"
local-zone: "geo-prod.do.dsp.mp.microsoft.com" redirect
local-data: "geo-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "geover-prod.do.dsp.mp.microsoft.com" redirect
local-data: "geover-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "g.msn.com" redirect
local-data: "g.msn.com A 0.0.0.1"
local-zone: "h1.msn.com" redirect
local-data: "h1.msn.com A 0.0.0.1"
local-zone: "h2.msn.com" redirect
local-data: "h2.msn.com A 0.0.0.1"
local-zone: "i1.services.social.microsoft.com" redirect
local-data: "i1.services.social.microsoft.com A 0.0.0.1"
local-zone: "i1.services.social.microsoft.com.nsatc.net" redirect
local-data: "i1.services.social.microsoft.com.nsatc.net A 0.0.0.1"
local-zone: "i-bl6p-cor001.api.p001.1drv.com" redirect
local-data: "i-bl6p-cor001.api.p001.1drv.com A 0.0.0.1"
local-zone: "i-by3p-cor001.api.p001.1drv.com" redirect
local-data: "i-by3p-cor001.api.p001.1drv.com A 0.0.0.1"
local-zone: "i-by3p-cor002.api.p001.1drv.com" redirect
local-data: "i-by3p-cor002.api.p001.1drv.com A 0.0.0.1"
local-zone: "i-ch1-cor001.api.p001.1drv.com" redirect
local-data: "i-ch1-cor001.api.p001.1drv.com A 0.0.0.1"
local-zone: "i-ch1-cor002.api.p001.1drv.com" redirect
local-data: "i-ch1-cor002.api.p001.1drv.com A 0.0.0.1"
local-zone: "img-s-msn-com.akamaized.net" redirect
local-data: "img-s-msn-com.akamaized.net A 0.0.0.1"
local-zone: "inference.location.live.net" redirect
local-data: "inference.location.live.net A 0.0.0.1"
local-zone: "insiderppe.cloudapp.net" redirect
local-data: "insiderppe.cloudapp.net A 0.0.0.1"
local-zone: "i-sn2-cor001.api.p001.1drv.com" redirect
local-data: "i-sn2-cor001.api.p001.1drv.com A 0.0.0.1"
local-zone: "i-sn2-cor002.api.p001.1drv.com" redirect
local-data: "i-sn2-cor002.api.p001.1drv.com A 0.0.0.1"
local-zone: "kv101-prod.do.dsp.mp.microsoft.com" redirect
local-data: "kv101-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "kv201-prod.do.dsp.mp.microsoft.com" redirect
local-data: "kv201-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "kv401-prod.do.dsp.mp.microsoft.com" redirect
local-data: "kv401-prod.do.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "lb1.www.ms.akadns.net" redirect
local-data: "lb1.www.ms.akadns.net A 0.0.0.1"
local-zone: "licensing.mp.microsoft.com" redirect
local-data: "licensing.mp.microsoft.com A 0.0.0.1"
local-zone: "live.rads.msn.com" redirect
local-data: "live.rads.msn.com A 0.0.0.1"
local-zone: "ls2web.redmond.corp.microsoft.com" redirect
local-data: "ls2web.redmond.corp.microsoft.com A 0.0.0.1"
local-zone: "m.adnxs.com" redirect
local-data: "m.adnxs.com A 0.0.0.1"
local-zone: "mediaredirect.microsoft.com" redirect
local-data: "mediaredirect.microsoft.com A 0.0.0.1"
local-zone: "mobile.pipe.aria.microsoft.com" redirect
local-data: "mobile.pipe.aria.microsoft.com A 0.0.0.1"
local-zone: "msedge.net" redirect
local-data: "msedge.net A 0.0.0.1"
local-zone: "msftncsi.com" redirect
local-data: "msftncsi.com A 0.0.0.1"
local-zone: "msntest.serving-sys.com" redirect
local-data: "msntest.serving-sys.com A 0.0.0.1"
local-zone: "oca.telemetry.microsoft.com" redirect
local-data: "oca.telemetry.microsoft.com A 0.0.0.1"
local-zone: "oca.telemetry.microsoft.com.nsatc.net" redirect
local-data: "oca.telemetry.microsoft.com.nsatc.net A 0.0.0.1"
local-zone: "officeclient.microsoft.com" redirect
local-data: "officeclient.microsoft.com A 0.0.0.1"
local-zone: "oneclient.sfx.ms" redirect
local-data: "oneclient.sfx.ms A 0.0.0.1"
local-zone: "pre.footprintpredict.com" redirect
local-data: "pre.footprintpredict.com A 0.0.0.1"
local-zone: "preview.msn.com" redirect
local-data: "preview.msn.com A 0.0.0.1"
local-zone: "pti.store.microsoft.com" redirect
local-data: "pti.store.microsoft.com A 0.0.0.1"
local-zone: "query.prod.cms.rt.microsoft.com" redirect
local-data: "query.prod.cms.rt.microsoft.com A 0.0.0.1"
local-zone: "rad.msn.com" redirect
local-data: "rad.msn.com A 0.0.0.1"
local-zone: "redir.metaservices.microsoft.com" redirect
local-data: "redir.metaservices.microsoft.com A 0.0.0.1"
local-zone: "register.cdpcs.microsoft.com" redirect
local-data: "register.cdpcs.microsoft.com A 0.0.0.1"
local-zone: "reports.wes.df.telemetry.microsoft.com" redirect
local-data: "reports.wes.df.telemetry.microsoft.com A 0.0.0.1"
local-zone: "s0.2mdn.net" redirect
local-data: "s0.2mdn.net A 0.0.0.1"
local-zone: "schemas.microsoft.akadns.net" redirect
local-data: "schemas.microsoft.akadns.net A 0.0.0.1"
local-zone: "search.msn.com" redirect
local-data: "search.msn.com A 0.0.0.1"
local-zone: "secure.adnxs.com" redirect
local-data: "secure.adnxs.com A 0.0.0.1"
local-zone: "secure.flashtalking.com" redirect
local-data: "secure.flashtalking.com A 0.0.0.1"
local-zone: "services.wes.df.telemetry.microsoft.com" redirect
local-data: "services.wes.df.telemetry.microsoft.com A 0.0.0.1"
local-zone: "settings.data.glbdns2.microsoft.com" redirect
local-data: "settings.data.glbdns2.microsoft.com A 0.0.0.1"
local-zone: "settings.data.microsoft.com" redirect
local-data: "settings.data.microsoft.com A 0.0.0.1"
local-zone: "settings-sandbox.data.microsoft.com" redirect
local-data: "settings-sandbox.data.microsoft.com A 0.0.0.1"
local-zone: "settings-ssl.xboxlive.com" redirect
local-data: "settings-ssl.xboxlive.com A 0.0.0.1"
local-zone: "settings-win.data.microsoft.com" redirect
local-data: "settings-win.data.microsoft.com A 0.0.0.1"
local-zone: "settings-win-ppe.data.microsoft.com" redirect
local-data: "settings-win-ppe.data.microsoft.com A 0.0.0.1"
local-zone: "sn3301-c.1drv.com" redirect
local-data: "sn3301-c.1drv.com A 0.0.0.1"
local-zone: "sn3301-e.1drv.com" redirect
local-data: "sn3301-e.1drv.com A 0.0.0.1"
local-zone: "sn3301-g.1drv.com" redirect
local-data: "sn3301-g.1drv.com A 0.0.0.1"
local-zone: "so.2mdn.net" redirect
local-data: "so.2mdn.net A 0.0.0.1"
local-zone: "spynet2.microsoft.com" redirect
local-data: "spynet2.microsoft.com A 0.0.0.1"
local-zone: "spynetalt.microsoft.com" redirect
local-data: "spynetalt.microsoft.com A 0.0.0.1"
local-zone: "spyneteurope.microsoft.akadns.net" redirect
local-data: "spyneteurope.microsoft.akadns.net A 0.0.0.1"
local-zone: "sqm.df.telemetry.microsoft.com" redirect
local-data: "sqm.df.telemetry.microsoft.com A 0.0.0.1"
local-zone: "sqm.telemetry.microsoft.com" redirect
local-data: "sqm.telemetry.microsoft.com A 0.0.0.1"
local-zone: "sqm.telemetry.microsoft.com.nsatc.net" redirect
local-data: "sqm.telemetry.microsoft.com.nsatc.net A 0.0.0.1"
local-zone: "static.2mdn.net" redirect
local-data: "static.2mdn.net A 0.0.0.1"
local-zone: "storecatalogrevocation.storequality.microsoft.com" redirect
local-data: "storecatalogrevocation.storequality.microsoft.com A 0.0.0.1"
local-zone: "storeedgefd.dsx.mp.microsoft.com" redirect
local-data: "storeedgefd.dsx.mp.microsoft.com A 0.0.0.1"
local-zone: "store-images.s-microsoft.com" redirect
local-data: "store-images.s-microsoft.com A 0.0.0.1"
local-zone: "support.microsoft.com" redirect
local-data: "support.microsoft.com A 0.0.0.1"
local-zone: "survey.watson.microsoft.com" redirect
local-data: "survey.watson.microsoft.com A 0.0.0.1"
local-zone: "t0.ssl.ak.dynamic.tiles.virtualearth.net" redirect
local-data: "t0.ssl.ak.dynamic.tiles.virtualearth.net A 0.0.0.1"
local-zone: "t0.ssl.ak.tiles.virtualearth.net" redirect
local-data: "t0.ssl.ak.tiles.virtualearth.net A 0.0.0.1"
local-zone: "telecommand.telemetry.microsoft.com" redirect
local-data: "telecommand.telemetry.microsoft.com A 0.0.0.1"
local-zone: "telecommand.telemetry.microsoft.com.nsatc.net" redirect
local-data: "telecommand.telemetry.microsoft.com.nsatc.net A 0.0.0.1"
local-zone: "telemetry.appex.bing.net" redirect
local-data: "telemetry.appex.bing.net A 0.0.0.1"
local-zone: "telemetry.microsoft.com" redirect
local-data: "telemetry.microsoft.com A 0.0.0.1"
local-zone: "telemetry.urs.microsoft.com" redirect
local-data: "telemetry.urs.microsoft.com A 0.0.0.1"
local-zone: "test.activity.windows.com" redirect
local-data: "test.activity.windows.com A 0.0.0.1"
local-zone: "tile-service.weather.microsoft.com" redirect
local-data: "tile-service.weather.microsoft.com A 0.0.0.1"
local-zone: "time.windows.com" redirect
local-data: "time.windows.com A 0.0.0.1"
local-zone: "tk2.plt.msn.com" redirect
local-data: "tk2.plt.msn.com A 0.0.0.1"
local-zone: "tsfe.trafficshaping.dsp.mp.microsoft.com" redirect
local-data: "tsfe.trafficshaping.dsp.mp.microsoft.com A 0.0.0.1"
local-zone: "urs.smartscreen.microsoft.com" redirect
local-data: "urs.smartscreen.microsoft.com A 0.0.0.1"
local-zone: "v10.vortex-win.data.metron.live.com.nsatc.net" redirect
local-data: "v10.vortex-win.data.metron.live.com.nsatc.net A 0.0.0.1"
local-zone: "v10.vortex-win.data.microsoft.com" redirect
local-data: "v10.vortex-win.data.microsoft.com A 0.0.0.1"
local-zone: "version.hybrid.api.here.com" redirect
local-data: "version.hybrid.api.here.com A 0.0.0.1"
local-zone: "view.atdmt.com" redirect
local-data: "view.atdmt.com A 0.0.0.1"
local-zone: "vortex-bn2.metron.live.com.nsatc.net" redirect
local-data: "vortex-bn2.metron.live.com.nsatc.net A 0.0.0.1"
local-zone: "vortex-cy2.metron.live.com.nsatc.net" redirect
local-data: "vortex-cy2.metron.live.com.nsatc.net A 0.0.0.1"
local-zone: "vortex.data.glbdns2.microsoft.com" redirect
local-data: "vortex.data.glbdns2.microsoft.com A 0.0.0.1"
local-zone: "vortex.data.metron.live.com.nsatc.net" redirect
local-data: "vortex.data.metron.live.com.nsatc.net A 0.0.0.1"
local-zone: "vortex.data.microsoft.com" redirect
local-data: "vortex.data.microsoft.com A 0.0.0.1"
local-zone: "vortex-db5.metron.live.com.nsatc.net" redirect
local-data: "vortex-db5.metron.live.com.nsatc.net A 0.0.0.1"
local-zone: "vortex-hk2.metron.live.com.nsatc.net" redirect
local-data: "vortex-hk2.metron.live.com.nsatc.net A 0.0.0.1"
local-zone: "vortex-sandbox.data.microsoft.com" redirect
local-data: "vortex-sandbox.data.microsoft.com A 0.0.0.1"
local-zone: "vortex-win.data.metron.live.com.nsatc.net" redirect
local-data: "vortex-win.data.metron.live.com.nsatc.net A 0.0.0.1"
local-zone: "vortex-win.data.microsoft.com" redirect
local-data: "vortex-win.data.microsoft.com A 0.0.0.1"
local-zone: "watson.microsoft.com" redirect
local-data: "watson.microsoft.com A 0.0.0.1"
local-zone: "watson.ppe.telemetry.microsoft.com" redirect
local-data: "watson.ppe.telemetry.microsoft.com A 0.0.0.1"
local-zone: "watson.telemetry.microsoft.com" redirect
local-data: "watson.telemetry.microsoft.com A 0.0.0.1"
local-zone: "watson.telemetry.microsoft.com.nsatc.net" redirect
local-data: "watson.telemetry.microsoft.com.nsatc.net A 0.0.0.1"
local-zone: "wdcpalt.microsoft.com" redirect
local-data: "wdcpalt.microsoft.com A 0.0.0.1"
local-zone: "wdcp.microsoft.com" redirect
local-data: "wdcp.microsoft.com A 0.0.0.1"
local-zone: "web.vortex.data.microsoft.com" redirect
local-data: "web.vortex.data.microsoft.com A 0.0.0.1"
local-zone: "wes.df.telemetry.microsoft.com" redirect
local-data: "wes.df.telemetry.microsoft.com A 0.0.0.1"
local-zone: "win10.ipv6.microsoft.com" redirect
local-data: "win10.ipv6.microsoft.com A 0.0.0.1"
local-zone: "win10-trt.msedge.net" redirect
local-data: "win10-trt.msedge.net A 0.0.0.1"
local-zone: "win1710.ipv6.microsoft.com" redirect
local-data: "win1710.ipv6.microsoft.com A 0.0.0.1"
local-zone: "wscont.apps.microsoft.com" redirect
local-data: "wscont.apps.microsoft.com A 0.0.0.1"
local-zone: "www.msedge.net" redirect
local-data: "www.msedge.net A 0.0.0.1"
local-zone: "www.msftconnecttest.com" redirect
local-data: "www.msftconnecttest.com A 0.0.0.1"
local-zone: "www.msftncsi.com" redirect
local-data: "www.msftncsi.com A 0.0.0.1"

DNSCrypt

Configuring DNSCrypt to send it's lookups through the VPN and not directly out your ppp interface is done using a socks proxy.

You can test that you're not getting DNS leaks by using dnsleak.com or this one from GRC. Providers like CloudFlare and Google (1.1.1.1, 8.8.8.8) use anycast which should be pointing to a server located to where your VPN exits.

/etc/dnscrypt-proxy/dnscrypt-proxy.toml

Using the sample dnscrypt config is fine, you will need to make these changes: 

listen_addresses = ['127.0.0.1:53000', '[::1]:53000']
proxy = "socks5://127.0.0.1:1080"

Dante

First install dante, you'll need to pin the testing repository. See: Alpine Linux package management#Repository pinning.

apk add dante-server@testing

Configure it like so:

/etc/sockd.conf

logoutput: stderr
internal: 127.0.0.1 port = 1080
external: tun0
clientmethod: none
socksmethod: none
user.unprivileged: sockd

# Allow connections from localhost to any host
client pass {
        from: 127.0.0.1/8 to: 0.0.0.0/0
	log: error # connect/disconnect
}

# Generic pass statement - bind/outgoing traffic
socks pass {
        from: 0.0.0.0/0 to: 0.0.0.0/0
        command: bind connect udpassociate
        log: error # connect disconnect iooperation
}

# Generic pass statement for incoming connections/packets
socks pass {
        from: 0.0.0.0/0 to: 0.0.0.0/0
        command: bindreply udpreply
        log: error # connect disconnect iooperation
}

Finally the services to the the default run level:

rc-update add sockd default

rc-update add unbound default

rc-update add dnscrypt-proxy default

Random number generation

There are two ways to assist with random number generation Entropy and randomness. This can be particularly useful if you're generating your own Diffie-Hellman nonce file, used in the FreeRadius EAP-TLS configuration section. Or for that matter any process which requires lots of random number generation such as generating certificates or public private keys.

Haveged

Haveged is a great way to improve random number generation speed. It uses the unpredictable random number generator based upon an adaptation of the HAVEGE algorithm.

Install haveged:

apk add haveged

Start haveged service:

service haveged start

Add service to boot

rc-update add haveged default

Start rngd service:

service haveged start

Add service to boot:

rc-update add haveged default

rng-tools with bcm2708-rng

Pre Alpine Linux 3.8 (which includes rngd 5)

All Raspberry Pis come with the bcm2708-rng random number generator on board. If you are doing this project on a Raspberry Pi then you may choose to use this also.

Add the kernel module to /etc/modules:

echo "bcm2708-rng" > /etc/modules

Insert module:

modprobe bcm2708-rng

Install rng-tools:

apk add rng-tools

Set the random device (/dev/random) and rng device (/dev/hwrng) in /etc/conf.d/rngd

RNGD_OPTS="--no-drng=1 --no-tpm=1 -o /dev/random -r /dev/hwrng"

Post Alpine Linux 3.8 (which includes rngd 6)

With AlpineLinux 3.8 you don't have to insert the module as it is already built in the kernel.

Additionally the syntax has changed for rngd so for /etc/conf.d/rngd you'll need

RNGD_OPTS="-x1 -o /dev/random -r /dev/hwrng"

Start rngd service:

service rngd start

Add service to boot:

rc-update add rngd default

You can test it with:

cat /dev/hwrng | rngtest -c 1000

You should see something like: 

rngtest 5
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 1000
rngtest: FIPS 140-2 failures: 0
rngtest: FIPS 140-2(2001-10-10) Monobit: 0
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 0
rngtest: FIPS 140-2(2001-10-10) Long run: 0
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=117.709; avg=808.831; max=3255208.333)Kibits/s
rngtest: FIPS tests speed: (min=17.199; avg=22.207; max=22.653)Mibits/s
rngtest: Program run time: 25178079 microseconds

It's possible you might have a some failures. That's okay, two runs I did previously had a failure each.

WiFi 802.1x EAP and FreeRadius

A more secure way than using pre-shared keys (WPA2) is to use EAP-TLS and use separate certificates for each device. See FreeRadius EAP-TLS configuration

VPN Tunnel on specific subnet

As mentioned earlier in this article it might be useful to have a VPN subnet and a non-VPN subnet. Typically gaming consoles or computers might want low-latency connections. For this exercise we use fwmark.

We expand the network to look like this:

Network Diagram with IPv4 tunnel
Network Diagram with IPv4 tunnel

Install the necessary packages:

apk add openvpn iproute2 iputils

/etc/modules

You'll want to add the tun module 

tun

/etc/iproute2/rt_tables

Add the two routing tables to the bottom of rt_tables. It should look something like this: 

#
# reserved values
#
255	local
254	main
253	default
0	unspec
#
# local
#
#1	inr.ruhep
1 ISP
2 VPN

/etc/network/interfaces

Next up add the virtual interface (really just a IP address to eth0) eth0:2, just under eth0 will do. 

# Route to VPN subnet
auto eth0:2
iface eth0:2 inet static
  address 192.168.2.1
  netmask 255.255.255.0
  broadcast 192.168.2.255
  post-up /etc/network/fwmark_rules

/etc/sysctl.d/local.conf

If you want to use fwmark rules you need to change this setting. It causes the router to still do source validation. 

# Needed to use fwmark
net.ipv4.conf.all.rp_filter = 2

fwmark won't work if you have this set to 1.

/etc/network/fwmark_rules

In this file we want to put the fwmark rules and set the correct priorities. 

#!/bin/sh

# Normal packets to go direct out WAN
/sbin/ip rule add fwmark 1 table ISP prio 100

# Put packets destined into VPN when VPN is up
/sbin/ip rule add fwmark 2 table VPN prio 200

# Prevent packets from being routed out when VPN is down.
# This prevents packets from falling back to the main table
# that has a priority of 32766
/sbin/ip rule add prohibit fwmark 2 prio 300

/etc/ppp/ip-up

Next up we want to create the routes that should be run when PPP comes online. There are special hooks we can use in ip-up and ip-down to refer to the IP address, ppp man file - Scripts You can also read about them in your man file if you have ppp-doc installed. 

#!/bin/sh
#
# This script is run by pppd when there's a successful ppp connection.
#

# Flush out any old rules that might be there
/sbin/ip route flush table ISP

# Add route to table from subnets on LAN
/sbin/ip route add 192.168.1.0/24 dev eth0 table ISP
/sbin/ip route add 192.168.2.0/24 dev eth0 table ISP

# Add route from IP given by ISP to the table
/sbin/ip rule add from ${IPREMOTE} table ISP prio 100

# Add a default route
/sbin/ip route add table ISP default via ${IPREMOTE} dev ${IFNAME}

/etc/ppp/ip-down

#!/bin/sh
#
# This script is run by pppd after the connection has ended.
#

# Delete the rules when we take the interface down
/sbin/ip rule del from ${IPREMOTE} table ISP prio 100

/etc/openvpn/route-up-fwmark.sh

OpenVPN needs similar routing scripts and it also has it's own special hooks that allow you to specify particular values. A full list is here OpenVPN man file - Environmental Variables 

#!/bin/sh
#
# This script is run by OpenVPN when there's a successful VPN connection.
#

# Flush out any old rules that might be there
/sbin/ip route flush table VPN

# Add route to table from 192.168.2.0/24 subnet on LAN
/sbin/ip route add 192.168.2.0/24 dev eth0 table VPN

# Add route from VPN interface IP to the VPN table
/sbin/ip rule add from ${ifconfig_local} table VPN prio 200

# Add a default route
/sbin/ip route add default via ${ifconfig_local} dev ${dev} table VPN

/etc/openvpn/route-pre-down-fwmark.sh

#!/bin/sh
#
# This script is run by OpenVPN after the connection has ended
#

# Delete the rules when we take the interface down
/sbin/ip rule del from ${ifconfig_local} table VPN prio 200

What I did find was when starting and stopping the OpenVPN service if you used:

service openvpn stop

The rules in route-pre-down-fwmark.sh were not executed.

However:

/etc/init.d/openvpn stop

seemed to work correctly.

Advanced IPtables rules that allow us to route into our two routing tables

This is an expansion of the previous set of rules. It sets up NAT masquerading for the 192.168.2.0 to go through the VPN using marked packets.

I used these guides to write complete this: 

#########################################################################
# Advanced routing rule set
# Uses 192.168.1.0 via ISP
#      192.168.2.0 via VPN
#
# Packets to/from 192.168.1.0/24 are marked with 0x1 and routed to ISP
# Packets to/from 192.168.2.0/24 are marked with 0x2 and routed to VPN
#
#########################################################################

#
# NAT Table
# This is where translation of packets happens and "forwarding" of ports
# to specific hosts.
#
*nat

# Set default policies for table
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]

# Port forwarding for Bittorrent
-A PREROUTING -i tun0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20
-A PREROUTING -i tun0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20

# Allows routing to our modem subnet so we can access the web interface
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE
-A POSTROUTING -s 192.168.2.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE

# Allows hosts of the network to use the VPN tunnel
-A POSTROUTING -o tun0 -j MASQUERADE

# Allows hosts of the network to use the PPP tunnel
-A POSTROUTING -o ppp0 -j MASQUERADE
COMMIT

#
# Filter Table
# This is where we decide to ACCEPT, DROP or REJECT things
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]

# Create rule chain per input interface for forwarding packets
:FWD_ETH0 - [0:0]
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]
:FWD_TUN0 - [0:0]

# Create rule chain per input interface for input packets (for host itself)
:IN_ETH0 - [0:0]
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]
:IN_TUN0 - [0:0]

# Create a log drop chain
:LOG_DROP - [0:0]

# Create a reject chain
:LOG_REJECT - [0:0]

# Pass input packet to corresponding rule chain
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0
-A INPUT -i tun0 -j IN_TUN0

# Track forwarded packets
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

# Pass forwarded packet to corresponding rule chain
-A FORWARD -i eth0 -j FWD_ETH0
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0
-A FORWARD -i tun0 -j FWD_TUN0

# Forward traffic to ISP
-A FWD_ETH0 -s 192.168.1.0/24 -j ACCEPT

# Forward traffic to VPN
-A FWD_ETH0 -s 192.168.2.0/24 -j ACCEPT

# Allow excepted server to be FORWARD to ppp0
#-A FWD_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT

# Forward SSH packets from network to modem
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Forward HTTP packets from network to modem
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Forward Bittorrent Port to workstation
-A FWD_TUN0 -d 192.168.2.20/32 -p tcp -m tcp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_TUN0 -d 192.168.2.20/32 -p udp -m udp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# SSH to Router
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# DNS to Router
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT

# FreeRadius Client (eg a UniFi AP)
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Ubiquiti UAP Device Discovery Broadcast
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 10001 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# NTP to Router
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Accept traffic to router on both subnets
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Allow excepted server to be INPUT to eth0 from LAN
#-A IN_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT

# SSH To Modem from Router
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# HTTP To Modem from Router
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Accept incoming tracked PPP0 connection
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

# Log dropped packets coming in on PPP0
-A IN_PPP0 -j LOG --log-prefix "DROP:INPUT " --log-level 6
-A IN_PPP0 -j LOG_DROP

# Accept incoming tracked TUN0 connection
-A IN_TUN0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

# Log dropped packets coming in on TUN0
-A IN_TUN0 -j LOG --log-prefix "DROP:INPUT " --log-level 6
-A IN_TUN0 -j LOG_DROP
COMMIT

#
# Mangle Table
# This is the place where our markings happen, whether they be 0x1 or 0x2
#
*mangle

# Set default policies for table
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]

# Restore CONNMARK to the MARK (If one doesn't exist then no mark is set)
-A PREROUTING -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff

# If packet MARK is 2, then it means there is already a connection mark and the
# original packet came in on VPN
-A PREROUTING -s 192.168.2.0/24 -m mark --mark 0x2 -j ACCEPT

# Check exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) are 0x1
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -m mark --mark 0x1 -j ACCEPT

# Mark packets coming from 192.168.2.0/24 are 0x2
-A PREROUTING -s 192.168.2.0/24 -j MARK --set-xmark 0x2/0xffffffff

# If packet MARK is 1, then it means there is already a connection mark and the
# original packet came in on ISP
-A PREROUTING -s 192.168.1.0/24 -m mark --mark 0x1 -j ACCEPT

# Mark packets 192.168.1.0/24 are 0x1
-A PREROUTING -s 192.168.1.0/24 -j MARK --set-xmark 0x1/0xffffffff

# Mark exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) as 0x1
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -j MARK --set-xmark 0x1/0xffffffff

# Set mark to 0 - This is for the modem. Otherwise it will mark with 0x1 or 0x2
-A PREROUTING -d 192.168.0.1/32 -j MARK --set-xmark 0x0/0xffffffff

# Save MARK to CONNMARK (remember iproute can't see CONNMARKs)
-A PREROUTING -j CONNMARK --save-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT

You may want to delete certain rules here that do not apply to you, eg the FreeRadius rules. That is covered later in this article.

OpenVPN Routing

Usually when you connect with OpenVPN the remote VPN server will push routes down to your system. We don't want this as we still want to be able to access the internet without the VPN. We have also created our own routes that we want to use earlier in this guide.

You'll need to add this to the bottom of your OpenVPN configuration file: 

# Prevents default gateway from being set on the default routing table
route-noexec

# Allows route-up script to be executed
script-security 2

# Calls custom shell script after connection to add necessary routes
route-up /etc/openvpn/route-up-fwmark.sh
route-pre-down /etc/openvpn/route-pre-down-fwmark.sh

My VPNs are arranged like this in /etc/openvpn:

OpenVPN configuration file for that server: 

countrycode.serverNumber.openvpn.conf

OpenVPN certs for that server: 

countrycode.serverNumber.openvpn/countrycode.serverNumber.openvpn.crt
countrycode.serverNumber.openvpn/countrycode.serverNumber.openvpn.key
countrycode.serverNumber.openvpn/myKey.crt
countrycode.serverNumber.openvpn/myKey.key

So I use this helpful script to automate the process of changing between servers: 

#!/bin/sh

vpn_server_filename=$1

rm /etc/openvpn/openvpn.conf
ln -s $vpn_server_filename /etc/openvpn/openvpn.conf
chown -R openvpn:openvpn /etc/openvpn
chmod -R a=-rwx,u=+rX /etc/openvpn
chmod u=x /etc/openvpn/*.sh*

if grep -Fxq "#CustomStuffHere" openvpn.conf
then
    echo "Not adding custom routes, this server has been used previously"
else
    echo "Adding custom route rules"
cat <<EOF >> /etc/openvpn/openvpn.conf

#CustomStuffHere
# Prevents default gateway from being set on the default routing table
route-noexec

# Allows route-up script to be executed
script-security 2

# Calls custom shell script after connection to add necessary routes
route-up /etc/openvpn/route-up-fwmark.sh
route-pre-down /etc/openvpn/route-pre-down-fwmark.sh

# Logging of OpenVPN to file
#log /etc/openvpn/openvpn.log
EOF

fi
echo "Remember to set BitTorrent port forward in VPN control panel"

That way I can simply change between servers by running:

changevpn.sh countrycode.serverNumber.openvpn

and then restart openvpn. I am also reminded to put the port forward through on the VPN control panel so my BitTorrent client is connectable:

service openvpn restart

Finally add openvpn to the default run level

rc-update add openvpn default

Creating a LAN only Subnet

In this section, we'll be creating a LAN only subnet. This subnet will be 192.168.3.0/24. The idea of this subnet is nodes in it cannot have their packets forwarded to the Internet, however they can be accessed via the other LAN subnets 192.168.1.0/24 and 192.168.2.0/24. This approach doesn't use VLANs although that would be recommended if you had a managed switch. The idea of this subnet is for things like WiFi access points, IP Phones which contact a local Asterisk server and of course printers.

At the end of this section we will have something like:

Network Diagram LAN ONLY Route with IPv4
Network Diagram LAN ONLY Route with IPv4

/etc/iproute2/rt_tables

First up we'll add a third routing table: 

3 LAN

/etc/network/interfaces

Add a an extra virtual interface (really just a IP address to eth0). 

# LAN Only
auto eth0:3
iface eth0:3 inet static
  address 192.168.3.1
  netmask 255.255.255.0
  broadcast 192.168.3.255
  post-up /etc/network/route_LAN

/etc/network/route_LAN

This file will have our route added to it 

#!/bin/sh

# Add routes from ISP to LAN
/sbin/ip route add 192.168.1.0/24 dev eth0 table LAN

# Add route from VPN to LAN
/sbin/ip route add 192.168.2.0/24 dev eth0 table LAN

# Add route from LAN to it's own table
/sbin/ip route add 192.168.3.0/24 dev eth0 table LAN

/etc/ppp/ip-up

Append a route from the LAN subnet to the ISP table 

# Add route to LAN subnet
/sbin/ip route add 192.168.3.0/24 dev eth0 table ISP

/etc/openvpn/route-up-fwmark.sh

Append a route from the LAN subnet to the VPN table 

# Add route to LAN only subnet
/sbin/ip route add 192.168.3.0/24 dev eth0 table VPN

/etc/ntpd.conf

Add a listen address for ntp (OpenNTPD).

You should now have: 

# Addresses to listen on (ntpd does not listen by default)
listen on 192.168.1.1
listen on 192.168.2.1
listen on 192.168.3.1

Devices needing the correct time will need to use this NTP server because they will not be able to get it from the Internet.

Blocking bogons

Our LAN now has 4 subnets in total that are possible:

  • 192.168.0.0/30 (connection between modem and router)
  • 192.168.1.0/24 (ISP table, directly routed out WAN)
  • 192.168.2.0/24 (VPN table, routed out VPN)
  • 192.168.3.0/24 (Null routed subnet for LAN only hosts)
  • 172.16.32.0/20 (VPN provider's network, so we can access things on the VPN's network).

Everything else should be rejected. No packets should ever be forwarded on 192.168.5.2 or 10.0.0.5 for example.

Installing ipset

Install ipset:

apk add ipset

Add it to start up:

rc-update add ipset default

Now we need to load the lists of addresses into ipset Securing Your Server using IPset and Dynamic Blocklists mentions a script which was particularly useful. This script could be run on a cron job if you wanted to regularly update it and for the full bogon list you should as they change when that address space has been allocated.

For the purpose of this we will be using just the bogon-bn-nonagg.txt list. 

0.0.0.0/8
10.0.0.0/8
100.64.0.0/10
127.0.0.0/8
169.254.0.0/16
172.16.0.0/12
192.0.0.0/24
192.0.2.0/24
192.168.0.0/16
198.18.0.0/15
198.51.100.0/24
203.0.113.0/24
224.0.0.0/4
240.0.0.0/4

This is unlikely to change as it's the IPV4 Reserved IP addresses space. The script: 

#! /bin/bash

# /usr/local/sbin/fullbogons-ipv4
# BoneKracker
# Rev. 11 October 2012
# Tested with ipset 6.13

# Purpose: Periodically update an ipset used in a running firewall to block
# bogons. Bogons are addresses that nobody should be using on the public
# Internet because they are either private, not to be assigned, or have
# not yet been assigned.
#
# Notes: Call this from crontab. Feed updated every 4 hours.

# target="http://www.team-cymru.org/Services/Bogons/fullbogons-ipv4.txt"
# Use alternative URL from pfSense, due to 404 error with URL above
target="https://files.pfsense.org/lists/bogon-bn-nonagg.txt"
ipset_params="hash:net"

filename=$(basename ${target})
firewall_ipset=${filename%.*}           # ipset will be filename minus ext
data_dir="/var/tmp/${firewall_ipset}"   # data directory will be same
data_file="${data_dir}/${filename}"

# if data directory does not exist, create it
mkdir -pm 0750 ${data_dir}

# function to get modification time of the file in log-friendly format
get_timestamp() {
    date -r $1 +%m/%d' '%R
}

# file modification time on server is preserved during wget download
[ -w ${data_file} ] && old_timestamp=$(get_timestamp ${data_file})

# fetch file only if newer than the version we already have
wget -qNP ${data_dir} ${target}

if [ "$?" -ne "0" ]; then
    logger -p cron.err "IPSet: ${firewall_ipset} wget failed."
    exit 1
fi

timestamp=$(get_timestamp ${data_file})

# compare timestamps because wget returns success even if no newer file
if [ "${timestamp}" != "${old_timestamp}" ]; then

    temp_ipset="${firewall_ipset}_temp"
    ipset create ${temp_ipset} ${ipset_params}

    #sed -i '/^#/d' ${data_file}            # strip comments
    sed -ri '/^[#< \t]|^$/d' ${data_file}   # occasionally the file has been xhtml

    while read network; do
        ipset add ${temp_ipset} ${network}
    done < ${data_file}

    # if ipset does not exist, create it
    ipset create -exist ${firewall_ipset} ${ipset_params}

    # swap the temp ipset for the live one
    ipset swap ${temp_ipset} ${firewall_ipset}
    ipset destroy ${temp_ipset}

    # log the file modification time for use in minimizing lag in cron schedule
    logger -p cron.notice "IPSet: ${firewall_ipset} updated (as of: ${timestamp})."

fi

Now you should see the list loaded into memory when you do:

ipset list

We want to save it so our router can refer to it next time it starts up so for that:

/etc/init.d/ipset save

Adding our allowed networks

IPv4

ipset create allowed-nets-ipv4 hash:net,iface family inet

Then you can add each of your allowed networks: 

ipset add allowed-nets-ipv4 192.168.0.0/30,eth1
ipset add allowed-nets-ipv4 192.168.1.0/24,eth0
ipset add allowed-nets-ipv4 192.168.2.0/24,eth0
ipset add allowed-nets-ipv4 192.168.3.0/24,eth0
ipset add allowed-nets-ipv4 127.0.0.0/8,lo
ipset add allowed-nets-ipv4 172.16.32.0/20,tun0

IPv6

For IPv6 if you've got any Unique local address ranges you may choose to add them:

ipset create allowed-nets-ipv6 hash:net,iface family inet6

ipset add allowed-nets-ipv6 fde4:8dba:82e1::/48,tun0
ipset add allowed-nets-ipv6 fde4:8dba:82e1:ffff::/64,eth0


Finally save the sets with this command so they can be loaded next boot:

/etc/init.d/ipset save

Restricting our LAN subnet with iptables, and blocking the bogons

Finally we can apply our iptables rules, to filter both 192.168.3.0/24 and make sure that subnets like 192.168.5.0/24 are not forwarded or accessible by our router. You will need to review these rules, and remove the ones that do not apply to you.

Don't forget to change your RADIUS rules if you moved your WiFi APs into the 192.168.3.0/24 subnet. You'll also need to edit /etc/raddb/clients.conf

I used a new table here called "raw". This table is more primitive than the filter table. It cannot have FORWARD rules or INPUT rules. Therefore you will still need a FORWARD rule in your filter table to block bogons originating from your LAN.

The only kind of rules we may use here are PREROUTING and OUTPUT. The OUTPUT rules will only filter traffic originating from our router's local processes, such as if we ran the ping command to a bogon range on the router's command prompt.

Traffic passes over the raw table, before connecting marking as indicated by this packet flow map: Netfilter packet flow graph this means we don't have to strip the mark off the bogon range in the mangle table anymore. 

#########################################################################
# Advanced routing rule set
# Uses 192.168.1.0 via ISP
#      192.168.2.0 via VPN
#      192.168.3.0 via LAN
#
# Packets to/from 192.168.1.0/24 are marked with 0x1 and routed to ISP
# Packets to/from 192.168.2.0/24 are marked with 0x2 and routed to VPN
# Packets to/from 192.168.3.0/24 are routed to LAN and not forwarded onto
#                                    the internet
#
#########################################################################

#
# Raw Table
# This table is the place where we drop all illegal packets from networks that
# do not exist
#
*raw
:PREROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]

# Create a log drop chain
:LOG_DROP_BOGON - [0:0]

# Create an output chain
:OUT_PPP0 - [0:0]
:OUT_TUN0 - [0:0]

# Allows traffic from VPN tunnel
-A PREROUTING -s 172.16.32.0/20 -i tun0 -j ACCEPT

# Allows traffic to VPN tunnel
-A PREROUTING -d 172.16.32.0/20 -j ACCEPT

# Block specified bogons coming in from ISP and VPN
# (unlikely to happen as they filter them on their router)
-A PREROUTING -i ppp0 -m set --match-set bogon-bn-nonagg src -j LOG_DROP_BOGON
-A PREROUTING -i tun0 -m set --match-set bogon-bn-nonagg src -j LOG_DROP_BOGON

# Allows my excepted ranges.
-A PREROUTING -m set --match-set allowed-nets-ipv4 src,src -j ACCEPT

# Pass output interface to corresponding chain
-A OUTPUT -o ppp0 -j OUT_PPP0
-A OUTPUT -o tun0 -j OUT_TUN0

# Log drop chain
-A LOG_DROP_BOGON -j LOG --log-prefix "Dropped Bogon (ipv4) : " --log-level 6
-A LOG_DROP_BOGON -j DROP

# Block packets originating from the router destined to bogon ranges
-A OUT_PPP0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON

# Blocks packets originating from the router destined to bogon ranges
-A OUT_TUN0 -d 172.16.32.0/20 -j ACCEPT
-A OUT_TUN0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON
COMMIT

#
# NAT Table
# This is where translation of packets happens and "forwarding" of ports
# to specific hosts.
#
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]

# Port forwarding for Bittorrent
-A PREROUTING -i tun0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20
-A PREROUTING -i tun0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20

# Allows routing to our modem subnet so we can access the web interface
-A POSTROUTING -s 192.168.1.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE
-A POSTROUTING -s 192.168.2.0/24 -d 192.168.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -j MASQUERADE

# Allows hosts of the network to use the VPN tunnel
-A POSTROUTING -o tun0 -j MASQUERADE

# Allows hosts of the network to use the PPP tunnel
-A POSTROUTING -o ppp0 -j MASQUERADE
COMMIT

#
# Filter Table
# This is where we decide to ACCEPT, DROP or REJECT things
#
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]

# Create rule chain per input interface for forwarding packets
:FWD_ETH0 - [0:0]
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]
:FWD_TUN0 - [0:0]

# Create rule chain per input interface for input packets (for host itself)
:IN_ETH0 - [0:0]
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]
:IN_TUN0 - [0:0]

# Create a drop chain
:LOG_DROP - [0:0]

# Create a log drop chain
:LOG_DROP_BOGON - [0:0]

# Create a reject chain
:LOG_REJECT_LANONLY - [0:0]

# Create an output chain
:OUT_PPP0 - [0:0]
:OUT_TUN0 - [0:0]

# Pass input packet to corresponding rule chain
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0
-A INPUT -i tun0 -j IN_TUN0

# Track forwarded packets
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

# Pass forwarded packet to corresponding rule chain
-A FORWARD -i eth0 -j FWD_ETH0
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0
-A FORWARD -i tun0 -j FWD_TUN0

# Pass output interface to corresponding chain
-A OUTPUT -o ppp0 -j OUT_PPP0
-A OUTPUT -o tun0 -j OUT_TUN0

# Forward traffic to Modem
-A FWD_ETH0 -d 192.168.0.1/32 -j ACCEPT

# Allow routing to remote address on VPN
-A FWD_ETH0 -s 192.168.1.0/24 -d 172.16.32.1/32 -o tun0 -j ACCEPT
-A FWD_ETH0 -s 192.168.2.0/24 -d 172.16.32.1/32 -o tun0 -j ACCEPT

# Allow forwarding from LAN hosts to LAN ONLY subnet
-A FWD_ETH0 -s 192.168.1.0/24 -d 192.168.3.0/24 -j ACCEPT
-A FWD_ETH0 -s 192.168.2.0/24 -d 192.168.3.0/24 -j ACCEPT

# Allow LAN ONLY subnet to contact other LAN hosts
-A FWD_ETH0 -s 192.168.3.0/24 -d 192.168.1.0/24 -j ACCEPT
-A FWD_ETH0 -s 192.168.3.0/24 -d 192.168.2.0/24 -j ACCEPT

# Refuse to forward bogons to the internet!
-A FWD_ETH0 -m set --match-set bogon-bn-nonagg dst -j LOG_DROP_BOGON

# Forward traffic to ISP
-A FWD_ETH0 -s 192.168.1.0/24 -j ACCEPT

# Forward traffic to VPN
-A FWD_ETH0 -s 192.168.2.0/24 -j ACCEPT

# Prevent 192.168.3.0/24 from accessing internet
-A FWD_ETH0 -s 192.168.3.0/24 -j LOG_REJECT_LANONLY

# Allow excepted server to be FORWARD to ppp0
#-A FWD_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT

# Forward SSH packets from network to modem
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Forward HTTP packets from network to mode
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.1.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_ETH1 -s 192.168.0.1/32 -d 192.168.2.0/24 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Forward Bittorrent Port to workstation
-A FWD_TUN0 -d 192.168.2.20/32 -p tcp -m tcp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_TUN0 -d 192.168.2.20/32 -p udp -m udp --dport 6881:6889 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# SSH to Router
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# DNS to Router
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT

# FreeRadius Client (eg a UniFi AP)
-A IN_ETH0 -s 192.168.3.10/32 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.3.10/32 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Ubiquiti UAP Device Discovery Broadcast
-A IN_ETH0 -s 192.168.3.10/32 -p udp -m udp --dport 10001 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# NTP to Router
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.3.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Accept traffic to router on both subnets
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Allow excepted server to be INPUT to eth0 from LAN
#-A IN_ETH0 -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -o ppp0 -j ACCEPT

# SSH To Modem from Router
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# HTTP To Modem from Router
-A IN_ETH1 -s 192.168.0.1/32 -d 192.168.0.0/30 -p tcp -m tcp --sport 80 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

# Accept incoming tracked PPP0 connection
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

# Log dropped packets coming in on PPP0
-A IN_PPP0 -j LOG --log-prefix "DROP:INPUT (ipv4) " --log-level 6
-A IN_PPP0 -j LOG_DROP

# Accept incoming tracked TUN0 connection
-A IN_TUN0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

# Log dropped packets coming in on TUN0
-A IN_TUN0 -j LOG --log-prefix "DROP:INPUT (ipv4) " --log-level 6
-A IN_TUN0 -j LOG_DROP

# Log dropped bogons that never got forwarded
-A LOG_DROP_BOGON -j LOG --log-prefix "Dropped Bogon forward (ipv4) " --log-level 6
-A LOG_DROP_BOGON -j DROP

# Log rejected packets
-A LOG_REJECT_LANONLY -j LOG --log-prefix "Rejected packet from LAN only range : " --log-level 6
-A LOG_REJECT_LANONLY -j REJECT --reject-with icmp-port-unreachable
COMMIT

#
# Mangle Table
# This is the place where our markings happen, whether they be 0x1 or 0x2
#
*mangle

# Set default policies for table
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]

# Restore CONNMARK to the MARK (If one doesn't exist then no mark is set)
-A PREROUTING -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff

# If packet MARK is 2, then it means there is already a connection mark and the
# original packet came in on VPN
-A PREROUTING -s 192.168.2.0/24 -m mark --mark 0x2 -j ACCEPT

# Check exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) are 0x1
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -m mark --mark 0x1 -j ACCEPT

# Mark packets coming from 192.168.2.0/24 are 0x2
-A PREROUTING -s 192.168.2.0/24 -j MARK --set-xmark 0x2/0xffffffff

# If packet MARK is 1, then it means there is already a connection mark and the
# original packet came in on ISP
-A PREROUTING -s 192.168.1.0/24 -m mark --mark 0x1 -j ACCEPT

# Mark packets 192.168.1.0/24 are 0x1
-A PREROUTING -s 192.168.1.0/24 -j MARK --set-xmark 0x1/0xffffffff

# Mark exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) as 0x1
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -j MARK --set-xmark 0x1/0xffffff

# Strip mark if packet is destined for modem
-A PREROUTING -d 192.168.0.1/32 -j MARK --set-xmark 0x0/0xffffffff

# Save MARK to CONNMARK (remember iproute can't see CONNMARKs)
-A PREROUTING -j CONNMARK --save-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT

Other Tips

Diagnosing firewall problems

netcat, netcat6

Netcat can be useful for testing if a port is open or closed or filtered.

apk add netcat-openbsd

After installing netcat we can use it like this:

Say we wanted to test for IPv6, UDP, Port 547 we would do this on the router:

nc -6 -u -l 547

and then this on the client to connect to it:

nc -u -v -6 2001:0db8:1234:0001::1 547

tcpdump

tcpdump can also be useful for dumping the contents of packets coming in on an interface:

apk add tcpdump

Then we can run it. This example captures all DNS traffic originating from 192.168.2.20.

tcpdump -i eth0 udp and src 192.168.2.20 and port 53

You can write the file out with the -w option, and view it in Wireshark locally on your computer. You can increase the verbosity with the -v option. Using -vv will be even more verbose. -vvv will show even more.

lbu cache

Configure lbu cache so that you don't need to download packages when you restart your router eg Local APK cache

This is particularly important as some of the images do not contain ppp-pppoe. This might mean you're unable to get an internet connection to download the other packages on boot.

lbu encryption /etc/lbu/lbu.conf

In /etc/lbu/lbu.conf you might want to enable encryption to protect your VPN keys. 

# what cipher to use with -e option
DEFAULT_CIPHER=aes-256-cbc

# Uncomment the row below to encrypt config by default
ENCRYPTION=$DEFAULT_CIPHER

# Uncomment below to avoid <media> option to 'lbu commit'
# Can also be set to 'floppy'
LBU_MEDIA=mmcblk0p1

# Set the LBU_BACKUPDIR variable in case you prefer to save the apkovls
# in a normal directory instead of mounting an external media.
# LBU_BACKUPDIR=/root/config-backups

# Uncomment below to let lbu make up to 3 backups
# BACKUP_LIMIT=3

Remember to set a root password, by default Alpine Linux's root account is passwordless.

passwd root

Backup apkprov

It's a good idea to back up your apk provision file. You can pull it off your router to your local workstation with:

scp -r root@192.168.2.1:/media/mmcblk0p1/<YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc ./

And decrypt it with:

openssl enc -d -aes-256-cbc -in <YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc -out <YOUR HOST NAME>.apkovl.tar.gz

It can be encrypted with:

openssl aes-256-cbc -salt -in <YOUR HOST NAME>.apkovl.tar.gz -out <YOUR HOST NAME>.apkovl.tar.gz.aes-256-cbc

Harden SSH

Generate a SSH key

ssh-keygen -t rsa -b 4096

You will want to put the contents of id_rsa.pub in /etc/ssh/authorized_keys

You can put multiple public keys on multiple lines if more than one person has access to the router.

/etc/ssh/sshd_config

A couple of good options to set in here can be: 

ListenAddress 192.168.1.1
ListenAddress 192.168.2.1

While this isn't usually a good idea, a router doesn't need more than one user. 

PermitRootLogin yes

The most important options: 

RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile  /etc/ssh/authorized_keys
PasswordAuthentication no
PermitEmptyPasswords no
AllowTcpForwarding no
X11Forwarding no

/etc/conf.d/sshd

You will want to add 

rc_need="net"

This instructs OpenRC to make sure the network is up before starting ssh.

Finally add sshd to the default run level

rc-update add sshd default


Additionally you may want to look at Secure Secure Shell and tighten OpenSSH's cryptography options.

References

Retrieved from "https://wiki.alpinelinux.org/w/index.php?title=Linux_Router_with_VPN_on_a_Raspberry_Pi&oldid=16945"