This may be simple ... or not.
I'd like to set up an iptables rule(s) to only permit connection by one or two specific IP addresses on eth0 and route valid connections to eth1. Assuming my public IP is 18.104.22.168, would that be something like:
iptables -A INPUT -i eth0 \! -s 22.214.171.124 -j DROP
and how about routing the traffic to eth1? Would that be:
iptables --table nat --append POSTROUTING --out-interface eth0 -j MASQUERADE
iptables --append FORWARD --in-interface eth1 -j ACCEPT
I'd like some advice before experimenting