ClientPort Communication Parameter [CPort]

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.

Usage

TCP/IP (client side only)

Default

Assigned dynamically per connection by the networking implementation. If you do not have firewall restrictions, do not use this parameter.

Description

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.

Specify a list or a range of port numbers to make multiple connections using a given data source or connect string. If you specify a single port number, your application can 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 or range of port numbers, the application keeps trying port numbers until it finds one to which it can successfully bind.

Examples

  • The following string 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 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