VRF or Virtual Routing and Forwarding (or perhaps Virtual Routing Functions) provide virtualization of the routing table. They are useful for isolating services and entire networks from each other while avoiding the complexity of network namespaces.
To make use of VRFs, you will need `iproute2` and a kernel that is capable of using eBPF installed. Kernel 5.4.19-r1 and later are capable of using eBPF.
The easiest way to define VRFs is to add them to /etc/network/interfaces:
auto vrf-mgmt iface vrf-mgmt inet manual pre-up ip link add vrf-mgmt type vrf table 42
You can then associate specific interfaces with VRFs using pre-up commands:
auto eth0 iface eth0 inet static address 220.127.116.11 netmask 255.255.255.0 gateway 18.104.22.168 pre-up ip link set eth0 master vrf-mgmt
VRF-based Service Isolation
Services can be isolated to specific VRFs when running OpenRC 0.42.1-r4 or newer. You can set the
$vrf variable in an
/etc/conf.d file for a service to isolate it in most cases.
For example, with sshd:
# echo 'vrf="vrf-mgmt"' >> /etc/conf.d/sshd # rc-service sshd restart