On the module's main page, click on the Ports and Networking icon to bring up the form shown in Figure 44.2.

In the Proxy addresses and ports table, select the Listed below option. In the table provided, each row defines a listening port and an optional address to which to bind. Any existing ports and addresses will be listed, followed by a single blank row for adding a new one. In the first empty field in the Port column, enter a port number like 8000 or 8080. In the Hostname/IP address column, either select All to accept connections on any of your system's interfaces or select the second option to enter an IP address in the adjacent text box.

Using this table, Squid can be configured to listen on as many ports as you like. Because only one blank row appears at a time, however, you will need to save and reopen the form to add more than one new port.

ICP is a protocol used by Squid to communicate with other proxies in a cluster. Fill in the ICP port field to listen on a port other than the default of 3130 for ICP. This is not generally necessary, however, as only other proxies ever use this protocol.

Squid will normally accept ICP connections on any IP address. To change this, select the second radio button in the Incoming UDP address field and enter one of your system's interface IPs into its text field. This can be useful if all of the other proxies that your server might want to communicate with are on a single internal LAN.

Hit the Save button at the bottom of the page to update the configuration file with your new settings, then hit the Apply Changes link back on the main page to activate them.