To start, I'v got 2 routers for DSL. One router is the ISP's that they sold me at sign up that they use for remote administration on my end. It's in bridge mode and also has the phone cord hooked into it. The 2nd router is mine, it's a cisco 806 that I'v configured to use NAT and has some firewall features turned on. I'v hooked the cisco into the rest of the 4 machines on my network. Works fine with windows.

I used the YAST configuration applet or whatever to put in all the values I need for the network; DNS, gateway, ip/subnet info. When I try to ping out to the cisco router I get network not reachable. The router itself and the card on the back of the machine both have on linklights, so I know they're working. I have an Abit NF7 and the port is autosensing, and I'v got 2 crossover cables hooked together with a coupler connecting them and it works fine but that might be causing an issue. When I ping loopback on the computer I get a response, so I know the card is good.

Actually, pinging the loopback adaptor doesn't necessarily mean the card is OK. Most kernels will send those packets to a psuedo device instead of to the card...

Any way, can you get the exact same machine to work in Windows? The whole crossover w/coupler thing sounds suspicious, I'm curious if you know for a fact that the same hardware setup does work in Windows.

Any way, you're routes are wrong, or you have a firewall (on the machine) blocking all outbound access. Unless you really screwed something up, I doubt it's the latter, so we'll work on the assumption that it's the former.

What is the output of
$ ifconfig -a
and
$ netstat -nra
?