Howto Block a Port in Squid Proxy , Ubuntu Linux

Here I will show you 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 (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 (192.168.0.101) try as follows:

acl block_port port 1234
acl no_block_port_ip src 192.168.1.5
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