How to Install Squid Proxy Server on CentOS

Prerequisites:

• CentOS operating system
• Access to a terminal window/command-line (Ctrl-Alt-T)
• A CentOS user with root or sudo priviledges
• The yum package installer, included by default
• A text editor, such as vim

Let’s begin the installation.

Login to your server via Putty.

Step 1: Refresh CentOS Software Repositories

 sudo yum -y update 

Step 2: Install Squid Package on CentOS

 yum -y install squid 

Now start Squid by entering the following command:

 systemctl start squid 

To set up an automatic start at boot:

 systemctl enable squid 

Review the status of the service, use:

 systemctl status squid 

In the example below, we see that the state is ‘Active.’

Configuring the Squid Proxy Server

The Squid configuration file is found at /etc/squid/squid.conf.

1. Open the file in your preferred text editor (vim was used in this example}:

 sudo vi /etc/squid/squid.conf 

2. Navigate to find the http_port option. Typically, this is set to listen on Port 3218. This port usually carries TCP traffic. If your system is configured for traffic on another port, change it here:

You may also set the proxy mode to transparent if you’d like to prevent Squid from modifying your requests and responses.

Change it as follows:

 http_port 1234 transparent 

3. Navigate to the http_acacess deny all option.

It is currently configured to block all HTTP traffic, and no web traffic is allowed as shown below.

Change this to the following:

 http_access allow all 

4. Restart the Squid service by entering:

 sudo systemctl restart squid 

Squid Proxy Server successfully installed.

Thank You!