This setting in the ColdFusion Administrator enables line debugging in ColdFusion. We advise leaving this disabled in your production environment, and also if you do not intend to use line debugging.

The debugger server listens for commands from the ColdFusion Builder client on a random available port. This could be a problem if ColdFusion (and hence the debugger server) is behind a firewall. As a workaround, you can specify a fixed debugger server port number and allow this port through the firewall. To set a fixed debugger server port number, specify the following JVM argument on the Java and JVM page of the ColdFusion Administrator (or the appropriate place for your JEEE Application Server), replacing portNumber with the port you want to use. You can also edit this directly in the jvm.config file:

-DDEBUGGER_SERVER_PORT={portNumber} (where {portNumber} is the port you wish to use).

ColdFusion Debugger