FreeBSD is a powerful and flexible operating system that allows for advanced network routing configurations. One way to enhance this capability is by using Forwarding Information Bases (FIBs), which enable administrators to segregate network traffic and apply different routing rules to specific subsets of traffic. In this post, we will walk you through the process of adding FIBs to your FreeBSD system.

Add FIB

sysctl net.fibs=2
setfib 1 route add default 172.16.1.1

Make it Persistent

echo 'net.fibs=2' >> /etc/sysctl.conf

Jails

add in jail.conf:

exec.fib=1;

Change Interface FIB

ifconfig lo1 fib 1

Add Connected Routes To allfibs

The allfibs line is needed for FreeBSD 12+.

echo 'net.add_addr_allfibs=0' >> /boot/loader.conf