Hi All, Sorry I sent it with wrong subject last time I have ISA server using as web proxy for my clients.... My clients deviced to categories: 1- Internal LAN with 10..x.x.x subnet mask 255.0.0.0 2- Wan and dialup users with 10.1.x.x subnet mask 255.255.0.0 Suddenly after two years of its working fine, yesterday the Wan user stopped browseing... they can ping the ISA server but they cannot use it for browseing the internet.... my Internal LAN users working fine.... When I troublshooting the problem I discovered that ISA server only works after I changer the port number from 8888 to 8585 but this not for long time... after 3 hours of working with the new port number it's stopped again.... All of these happened only for my Wan users IPs ... My lan IPs can work without facing any problem... Please help me to find out a solution fo this issue.. Awaiting for your reply.... Regards,, Magdy