Hi Simon, If it works without the firewall client enabled, but it doesn't work when it is enabled, then I'd bet a dollar that it's a name resolution issue. HTH, Tom Thomas W Shinder www.isaserver.org/shinder ISA Server and Beyond: http://tinyurl.com/1jq1 Configuring ISA Server: http://tinyurl.com/1llp _____ From: Simon Weaver [mailto:Simon.Weaver@xxxxxxxx] Sent: Saturday, September 27, 2003 8:20 AM To: [ISAserver.org Discussion List] Subject: [isalist] Allow Port 319 through ISA http://www.ISAserver.org Hi everyone I think I am going completely mad!! I have a 3rd party application that communicates on Port 319 - If the users Win2k Workstations Firewall Client are enabled, the application does not respond. If they disable the firewall client, the program works fine. Can someone tell me where I need to enable port 319 through the firewall please? Thank you so much..... I think I am losing it :-( Sim