Configure Squid Proxy On Ubuntu 20.04

Accuracy note — 13 October 2026: Ubuntu 20.04 ended standard security maintenance in May 2025. Use a supported Ubuntu release for new installations, or confirm appropriate Ubuntu Pro coverage for an existing 20.04 system. See the Ubuntu release cycle. The access-control text below has been corrected; older screenshots may show the previous configuration.

Introduction: Squid Proxy

Configuring Squid Proxy on Ubuntu 20.04 is a straightforward process that can enhance your network’s performance and security. Begin by installing Squid with the command sudo apt-get install squid. Once installed, you can modify the Squid configuration file located at /etc/squid/squid.conf. This file allows you to set access control rules, cache settings, and network permissions. After making your adjustments, restart the Squid service with sudo systemctl restart squid to apply the changes. To ensure proper functionality, check the Squid status using sudo systemctl status squid. Properly configuring Squid Proxy can significantly improve your network’s efficiency and browsing experience.

Squid Proxy is a Linux-based application. This is a full-featured caching proxy supporting popular network protocols like HTTP, HTTPS, FTP, and more.

How to set up a Squid Proxy on Ubuntu 20.04

Now, let’s start with installing and configuring a squid proxy server on Ubuntu 20.04.

Update the repository and install the required packages.

apt update -y
apt install vim screen curl net-tools -y

install squid service

apt -y install squid

Squid service have installed succesfully you can check the status with the following command

systemctl status squid

you can manage the squid service with the following command.

systemctl start squid
systemctl stop squid
systemctl restart squid

Enable squid service so it’s run automatically after reboot

systemctl enable squid

If you want to disable the service then you can use this command

systemctl disable squid

now we are going to edit squid.conf so first take a backup for security

cp -rp /etc/squid/squid.conf /etc/squid/squid.conf-bkp

Open squid.conf file with your favorite editor

vim /etc/squid/squid.conf

Edit http_port with your choice, the default port is 3128

http_port 31428

Keep http_access deny all as the final access rule. Never replace it with an unrestricted allow rule: that creates an open proxy. Allow only trusted client addresses and authenticated users before the final deny, retain Squid’s default unsafe-port restrictions, and restrict the listening port with your firewall. See Squid access-control documentation.

http_access deny all

Add Squid ACL

acl trusted_clients src <trusted-client-IP-or-CIDR>

:wq! (save file)

Securing user authorization

Install necessary tools

apt install apache2-utils -y

create user authantication with following command

htpasswd -c /etc/squid/passwords testsquid

here testsquid is a user and passwords is a file there stores user authantication

now configure user details in squid.conf file
open squid.conf file then add following lines

vim /etc/squid/squid.conf

auth_param basic program /usr/lib/squid/basic_ncsa_auth /etc/squid/passwords
auth_param basic realm proxy
acl authenticated proxy_auth REQUIRED
# Keep the default Safe_ports and SSL_ports restrictions above these rules.
http_access allow trusted_clients authenticated
http_access deny all

then save and close the file

:wq! (save file)

sestart squid service

systemctl restart squid

test your setup with following command

curl --proxy http://<your-proxy-IP>:31428 --proxy-user testsquid https://example.com

Curl prompts for the password rather than embedding it in shell history. Basic proxy authentication does not encrypt credentials between the client and an HTTP proxy; use a trusted private network or an encrypted tunnel. Confirm the helper path with dpkg -L squid | grep basic_ncsa_auth, validate with squid -k parse, and test that requests from untrusted addresses and without valid credentials are denied. See the official NCSA authentication example.