I installed Isa server behind a router Netopia that maps an public IP address with 4 Ip 192.168.0.1-4. The external NIC of isa is 192.168.1.1., the internal Nic is 10.0.0.65 with a publish internal web server. When I try to connect to Isa from Internet, it replay with a "no server found" and records "IP spoof" alert from Internet IP address. I think the problem is that packets arriving on the external interface but claiming to come from an internal IP (192.168.0.1). It's corrects? Only solution is to get for ISA external Nic a public IP? thanks mario tognetti