How to Block a Port in Squid Proxy in Ubuntu Linux

Here I will explain how to block a port using squid proxy server and open this port for a selected user.

First you have to open squid configuration
File /etc/squid/squid.conf

#vi /etc/squid/squid.conf

Locate your Access Control List (ACL) section in the file and add the following lines:

acl block_port port 1234
http_access deny block_port
http_access allow all

If you just want to skip a particular IP (192.168.0.100) try as follows:

acl block_port port 1234
acl no_block_port_ip src 192.168.0.200
http_access deny block_port! no_block_port_ip
http_access allow all

Close and save the file.

Restart your Squid Proxy Server:

# /etc/init.d/squid restart