Just stopped routing

[kareface]

I've had the server running with no problems for months on end.  No changes have been made, and everything was working fine till today.  It just stopped routing.  I can ping the server from the internal network, I can ping the clients from the server, I can ping google from the server.  All the settings are set the way the should be (afaik), but I can't resolve or ping anything on the wan from the client computers.  I have no idea what happened or why it's doing this.

[sai]

see anything on the console?