The OpenEdge RDBMS allows you to use the Minimum Dynamic Server Port (-minport) and the Maximum Dynamic Server Port (-maxport) server startup parameters to provide client access to a server that is behind a firewall. This communication is possible only when access to the server can be limited. You supply this limit when you specify a group of port numbers with the -minport and -maxport parameters.

For example, suppose you start the following two login brokers:

A client requesting a connection from the first broker, demosv1, is assigned a port number in the range of 4000 to 4040. The 4000-to-4040 range limits access to the server by limiting communication to just 41 ports.

The default for -minport is 1025 for all platforms. Ports lower than 1025 are usually reserved for system TCP and UDP. The default for -maxport is 2000 for all platforms. Remember that some operating systems choose transient client ports in the 32,768-to-65,535 range. Choosing a port in this range might produce unwanted results.