I've setup a Debian Sarge host that has two NICs - eth0 (WAN) and eth1 (LAN). My eth0 is getting a dynamic IP from Comcast and I'm able to ping the Internet while directly on the firewall.

The eth1 (LAN) interface has an address of 10.1.0.1 and is connected to a Linksys router, which uses a static IP of 10.1.0.2. The Linksys router has a local IP of 10.1.1.1 and distributes DHCP starting at 10.1.1.100.

While behind the Linksys router, I'm using my laptop (10.1.1.100) and can ping the following...

Linksys LAN (10.1.1.1)
Linksys WAN (10.1.0.2)

Linux LAN (10.1.0.1)
Linux WAN (67.183.x.x)

The problem is that I'm unable to ping anything past the Linux firewall's eth0 (WAN) interface.

I've added logging for all traffic in and out of the eth1 (LAN) interface. There is obviously log activity when pinging the above address, but the logs are silent when I try to ping the Internet. This leads me to believe that there is a problem with the settings for the Linksys router, but I have no idea what.

My Linux /etc/resolv.conf and Linksys DNS servers are both set to use 204.127.199.8 and 63.240.76.198.

Any ideas?