I am using ISA server SP1, I have noticed that some of my ip addresses are unable to browse the internet. These are not Secure NAT clients just using the ISA server firewall as the router. The interesting thing is that most ip addresses work but a small block maybe 20 are unable to surf at all. If I change my DHCP to go straight to the router by passing the ISA Server the same IP addreses that didn't work now work. This problem was also there before I upgraded to SP2 Any ideas?? Keyth