I have all of the machines in office A on the 192.168.1.X network. We have a Netgear FVS318 VPN Router in both office A and office B, and office B is on the 192.168.3.X network. The VPN works perfectly with all of the hosts that are set up in both offices, and we've been using them for a few months now. I can ping between networks, ie the host 192.168.1.152 can ping 192.168.3.50 and vice versa. We have both Linux mahines and Windows machines on the .1.X and Windows machines on the .3.X. Every machine can ping, use SMB, VNC, and SSH (where servers apply) to every other machine.
I recently added a RHEL 2.1 host as 192.168.1.204 and it cannot see the 192.168.3.X. I also cannot see it from the .3.X. It and all of it's services work perfectly from .1.X but it doesn't exist from the .3.X network. I have 192.168.1.202 and 192.168.1.203 as Linux servers also, but didn't need to do anything funny to make them visible to the .3.X. I've checked the firewall/ipchains rules and nothing excludes that subnet. Anyone have any other ideas on what I should check?