I have a server 128.187.2.0/16 and 128.187.1.0/16 that was setup by a vendor. I have a host on 128.187.2.1 and 128.187.1.1 side with the following eth1: 128.187.3.1/24 and eth2: 128.187.4.1/24 each side to talk to the other in the event that one of the network card goes down. I have a firewall setup like the following. eth1: 128.187.3.1/24 and eth2: 128.187.4.1/24 - with clients on each side of the lan with default gateway being the interface that it is connected to. The 128.187.2.1 is on the hub that eth2 is connected to and 128.187.1.1 is on the hub that eth1 is connected to. I have done the following: echo 1 > /proc/sys/net/ipv4/ip_forward ip route replace 128.187.1.1 dev eth1 ip route replace 128.187.2.1 dev eth2 From the firewall I can ping 128.187.1.1 & 128.187.2.1. clients from the 128.187.3.0 side can''t ping 128.187.2.1 and clients from the 128.187.4.0 side can''t ping 128.187.1.1. How can I allow hosts on the eth1: 128.187.3.1/24 to ping 128.187.2.1 and hosts on eth2: 128.187.4.1/24 to ping 128.187.1.1. Thanks in Advance.