{ ClientPort | CPORT }=port-number

TCP/IP (client side only)

Assigned dynamically per connection by the networking implementation. If you do not have firewall restrictions, it is recommended that you do not use this protocol option.

This option is provided for connections across firewalls, as firewall software filters according to TCP/UDP port. It is recommended that you do not use this protocol option unless you need to for firewall reasons.

The ClientPort option designates the port number on which the client application communicates using TCP/IP. You can specify a single port number, or a combination of individual port numbers and ranges of port numbers. For example:

It is best to specify a list or a range of port numbers if you want to make multiple connections using a given Data Source or a given connection 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 several minute 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.

• Host (IP) protocol option (client side only)
• DoBroadcast (DOBROAD) protocol option
• ServerPort (PORT) protocol option
• Communication protocols
• Connecting across a firewall

The following connection string fragment makes a connection from an application using port 6000 to a database server named my-server using port 5000:

CommLinks=tcpip(ClientPort=6000;ServerPort=5000);ServerName=my-server

The following connection string fragment makes a connection from an application that can uses the specified ports for communicating with a database server named my-server using the default server port:

CommLinks=tcpip(ClientPort=5040,5050-5060,5070);
ServerName=my-server