Comodo blocking Internet access through internal net gateway machine

This should be an easy one to fix but I can’t figure it out.

I was running just fine on Windows XP with all systems go when I was connected directly to the Internet.

Now, I am running another machine as a gateway machine. This gateway machine accesses the Internet and acts as a DNS server, a DHCP server and a router, forwarding all Internet packets using NAT.

ipconfig on the Windows machine gives the gateway system correctly as the default gateway as does “route print”.

I can’t get any connectivity to the Internet to work at all if the Comodo firewall stays active on “custom policy” mode.

If I disable the firewall, it all works just great.

Since I am protected from incoming by the gateway machine’s firewall I am not all that worried about running with the Comodo firewall disabled, but it would be nice if I could continue to use it as a paranoid “belt and suspenders”.

I created a new trusted network but no help. It seems to be missing something about the default gateway.

Thanks in advance for any assistance; this feels like something really dumb that needs to be done here.

Hello, Is there anything in your Logs? Comodo → Firewall → Events

First, a basic question, can your Windows machine ping the gateway box?

What is the configuration of your gateway machine? It sounds like a Smoothwall or IPCop setup, or something very similar. If so, there is some checking that can be done there to verify things are working.

Probably the easiest way to find out what is going on, is to download Wireshark ( to your Windows machine, and see what the packets are on the wire. If something is being blocked, it should be fairly obvious with the network monitor.