Tag Name http_port
Usage http_port port
hostname: port
1.2.3.4 : port

Description
This tag name is used to specify the socket addresses where Squid will listen for HTTP client requests. Multiple socket addresses can be specified. There are three forms: port alone, hostname with port, and IP address with port. If hostname or IP address is specified, then Squid binds the socket to that specific address. This replaces the old “tcp_incoming_address” option. Most likely, there is no need to bind to a specific address, so the port number alone can be used. If Squid is to be run in accelerator mode, then it should listen on port 80 also, or instead.

Default http_port 3128

Example
Give the port number in which you want squid to listen to http client requests. Like…
http_port 8080
We can override the default port number by ‘-a ‘ command line option.
#/usr/local/squid/bin/squid -a 8080
This will start squid with port 8080, which overrides the port number in squid.conf. However this option cannot be used to override IP address

Caution
Before changing the port number, make sure no application in your box is running in the same port.

Note
http_port can be used to specify the tcp_incoming_address through which the cache listens to requests from other remote servers. http_port can be listed multiple times.