Hi Simon, Do any Winsock applications on the machine work correctly when the firewall client is enabled? Is the machine configured as a SecureNAT client too? I assume that the client side of the client/server app is not using HTTP/SSL. Thanks! Tom Thomas W Shinder www.isaserver.org/shinder <http://www.isaserver.org/shinder> ISA Server and Beyond: http://tinyurl.com/1jq1 Configuring ISA Server: http://tinyurl.com/1llp <http://tinyurl.com/1llp> -----Original Message----- From: Simon Weaver [mailto:Simon.Weaver@xxxxxxxx] Sent: Monday, October 13, 2003 7:41 AM To: [ISAserver.org Discussion List] Subject: [isalist] RE: Troubleshooting F/Wall Client Issues AD: Get Thawte's New Step-by-Step SSL Guide for MSIIS: http://www.isaserver.org/thawte/ Hi tom This application talks to a central server on the Internet - IT talks on a specific port number, which I have not created any rules for as of yet! I can use IE with or without the firewall client enabled. Just not this one application. If they turn off the firewall client, it works fine! Simon Weaver Technical Consultant MCSE+Internet / MCSE Windows 2000 Integrated Solutions Corp. Ltd http://www.iscl.net <http://www.iscl.net/>