I havent got this setup but shouldnt your router get the IP Address dynamically from your ISP, not your Suse box?
then you would have the router run DHCP on the interface the Suse box is connected to. Or your Suse box could be assigned a static IP to match the interface you are using on the router, using the router interface IP as the gateway IP for the Suse machine.
You shouldnt be running dhcpd on your Suse Box because that is offering dhcp to the router (i think).
your internet might still work because maybe you are offering dhcp not recieving and your eth0 may have a static IP that allows connection to the router?
Check your ifcfg-eth0?
Just a thourght ???
My setup is a box running RH 7.3 with a modem connection to the internet and a LAN connection to another box running RH 8.0/WinXP
I run dhcpd on eth0 from the RH 7.3 box that is connected to the internet via ppp0. I configure the RH 8.0 box to get it's address from eth0 of the RH 7.3 box. Then the RH 7.3 box routes packets from eth0 to ppp0 when needed. ie RH 8.0 Machine requests something from the internet.
Kinda like this
internet-----ppp0<-RH 7.3->eth0(running dhcpd)-----RH 8.0(configured to get IP address dynamically)
Hope this helps