Introduction

Squid is a popular open-source caching proxy server application that helps to reduce bandwidth and improve response times by caching and reusing frequently-requested web pages. It’s a great tool for increasing the speed and security of a web server. 

The Squid proxy server can be installed on Linux, Windows, and Mac OS X systems. In this tutorial, we will show you how to install Squid proxy server on Ubuntu 20.04.

Prerequisites

Before you begin this guide, you will need the following:

• Ubuntu 20.04 installed on a server
• Non-root user with sudo privileges

Step 1 – Installing Squid Proxy

The first step is to install the Squid proxy server on your Ubuntu 20.04 system. You can install the Squid package with the following command:

sudo apt install squid

Once the installation is complete, you can start the Squid service with the following command:

sudo systemctl start squid

You can also enable the Squid service to start automatically on system boot with the following command:

sudo systemctl enable squid

Step 2 – Configuring Squid Proxy

Once the Squid proxy server is installed, you can configure it by editing the squid.conf file. You can open the squid.conf file in your text editor with the following command:

sudo nano /etc/squid/squid.conf

The first thing you will need to do is to enable the HTTP port for the Squid proxy server. By default, the Squid proxy listens on port 3128. You can enable the HTTP port by uncommenting the following line in the squid.conf file:

http_port 3128

You can also enable the HTTPS port for the Squid proxy server. To do this, you will need to uncomment the following line in the squid.conf file:

https_port 3129

Once you have enabled the HTTP and HTTPS ports, you can save and close the squid.conf file.

Step 3 – Configuring Access Control Lists

The next step is to configure the access control lists (ACLs) for the Squid proxy. ACLs are used to define which users can access the Squid proxy and what content they can access. You can configure the ACLs by editing the acl.conf file. You can open the acl.conf file in your text editor with the following command:

sudo nano /etc/squid/acl.conf

In this file, you will need to create a list of users that are allowed to access the Squid proxy. You can do this by adding the following lines:

acl allowed_users src [IP ADDRESS]
http_access allow allowed_users

Replace [IP ADDRESS] with the IP address of the users that you want to allow to access the Squid proxy.

Next, you will need to configure the Squid proxy to only allow access to certain websites. You can do this by adding the following lines:

acl allowed_websites dstdomain [WEBSITE]
http_access allow allowed_websites

Replace [WEBSITE] with the website that you want to allow access to.

Once you are finished configuring the ACLs, you can save and close the acl.conf file.

Step 4 – Restarting Squid Proxy

Once you have finished configuring the Squid proxy, you will need to restart the service for the changes to take effect. You can restart the Squid service with the following command:

sudo systemctl restart squid

Conclusion

In this tutorial, we have shown you how to install and configure the Squid proxy server on Ubuntu 20.04. We have also shown you how to configure the access control lists to control which users and websites can access the Squid proxy. Now you should be able to setup a secure and efficient proxy server for your network.