Introduction

This wiki describes methods to bridge a wired and wireless interface to enable network communication between hosts reachable via either interface. This allows one or more wired hosts to share the wireless interface on the bridge host.

In my use case, I have a desk with a wired switch with multiple hosts connected. All wired devices on this switch can access my home wifi network via the bridge host's wireless interface.

I am only going to document the proxy ARP method as that's what I'm currently using. Please feel free to add additional methods and remove this section of the introduction.

Method 1: Proxy ARP

These steps result in a working solution where hosts on the wired side and hosts on the wireless side are all in the same ip network. There are no frills added, such as dhcp or automatic route entries for the wired hosts. Each wired host needs to have a manually configure IP address and an entry manually added to the bridge host's routing table.

Note: For your wired hosts, use IP addresses in the same IP range as the rest of your network but outside of the scope used by a local DHCP server, if applicable. You may need to reduce your DHCP scope to free up IP addresses for your wired bridge hosts.

Configure the network interfaces on your bridge host:

Contents of /etc/network/interfaces

auto lo
iface lo inet loopback

auto wlan0
iface wlan0 inet dhcp
	hostname wyse3030-3

auto eth0
iface eth0 inet manual
	pre-up ifconfig $IFACE up
	pre-down ifconfig $IFACE down

Notice that the wireless interface (wlan0) uses dhcp from the home network as usual and that an IP address is not used at all on the wired interface (eth0).

Enable and create a local start-up script to add route entries for your bridged wired hosts:

# rc-update add local default # touch /etc/local.d/RouteAdd.start # chmod +x /etc/local.d/RouteAdd.start

Add route statements for each bridged wired host:

Contents of /etc/local.d/RouteAdd.start

ip route add 10.0.0.51/32 dev eth0
ip route add 10.0.0.52/32 dev eth0
ip route add 10.0.0.53/32 dev eth0

Enable proxy arp:

Contents of /etc/sysctl.d/local.conf

{{{2}}}