I was assigned a.b.c.10/30 (Public IP) for my router and given a.b.c.9 as the gateway. I was also assigned x.y.z.128/25 (Public IP block) for my use. I want to setup a Linux router to handle this situation. My Linux box has 3 NICs, eth0 is a.b.c.10, eth1 I have assigned x.y.z.254, eth2 is unused at present.

I have eth1 connected to a network switch, and several devices connected. Let's say box A is x.y.z.129 with a gateway of x.y.z.254.

I have not connected to the network yet, as it is not live.

What settings do I need to make, beyond adding the 2 network definitions to the cards and having "route add default gw a.b.c.9 eth0"?

I may add a private 192.168.100.0/24 lan to eth2 later.