Designates the port number on which the client application communicates using TCP/IP.

Usage

TCP/IP (client side only)

Values

Integer

Default

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.

Remarks

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 parameter 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 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 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.

See also

• Host protocol option [IP]
• DoBroadcast protocol option [DOBROAD]
• ServerPort protocol option [PORT]
• Connecting across a firewall

Examples

The following connection string fragment makes 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 connection string fragment 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