I have a gateway box with two internet connections, eth0 and eth1, and a LAN connection eth2.
Currently eth1 is unused and eth2 LAN traffic is forwarded/masqueraded and sent to the internet via eth0.
What is the most straightforward way to send the eth2 LAN traffic to the internet via eth1? I want local traffic to still go via eth0.
(I am aware that I can tag packets in iptables, then route on the tag, but I was wondering whether I had missed a simpler solution.)