Designates the port number on which the client application communicates using TCP/IP. You may specify a single port number, or a combination of individual port numbers and ranges of port numbers.
Assigned dynamically per-connection by the networking implementation. If you do not have firewall restrictions, it is recommended that you do not use this parameter.
This option is provided for connections across firewalls, as firewall software filters according to TCP/UDP port. Do not use this parameter unless you need to for firewall reasons.
It is best to specify a list or a range of port numbers if you wish to make multiple connections using a given Data Source or given connect string. If you specify a single port number, then your application will be able to maintain only one connection at a time. In fact, even after closing the one connection, there is a short timeout period during which no new connection can be made using the specified port. When you specify a list and/or range of port numbers, the application keeps trying port numbers until it finds one to which it can successfully bind.
The following string make a connection from an application using port 6000 to a server named my_server using port 5000:
CommLinks=tcpip{ClientPort=6000;ServerPort=5000}; ServerName=my_server
The following string makes a connection from an application that can use ports 5050 through 5060, as well as ports 5040 and 5070, for communicating with a server named my_server using the default server port:
CommLinks=tcpip{ClientPort=5040,5050-5060,5070};ServerName=my_server