Can anyone help. I am currently experiencing a problem with a web site. The setup is as follows:- an IIS server comunicates with an application server through a Firewall-1(Nokia 440) and a Sunsceen (E250). MTS is used and talks using DCOM which has been configured to talk high (62500-62600). The firewalls will only let this DCOM range through. Every now and then the application server tries to reply to the IIS box using a low port (3072) and this is blocked by the firewalls. Why is the application server transmitting outside of the configured DCOM port range?