Internal service depends external conection

Hello guys, i have 2 servers here, one is the old server Suse 9.0 and the other is the new server OpenSuSE 10.3 with te same old server’s configuration. All have one problem with the conection. They have 2 interfaces eth0 external zone of net, the gateway, and eth1 the internal zone, the server provide services here.

Ok lets start if i remove the cable in eth0 (gateway) services like NFS, stop to atend the internal requisitions(eth1) of internal net, you know whats happening here?