Introduction
How to Install Squid Proxy Server on CentOS 7
1. Update the system:
sudo yum update
2. Install Squid:
sudo yum install squid
3. Start the Squid service:
sudo systemctl start squid
4. Enable the Squid service to start on boot:
sudo systemctl enable squid
5. Configure the Squid configuration file:
sudo vi /etc/squid/squid.conf
6. Restart the Squid service:
sudo systemctl restart squid
7. Allow the Squid port in the firewall:
sudo firewall-cmd –zone=public –add-port=3128/tcp –permanent
8. Reload the firewall:
sudo firewall-cmd –reload
Introduction
System administrators use the Squid Proxy to augment their content delivery. Squid Proxy specifically allows a server to cache frequently visited web pages.
How? When a user seeks a web page or file, the request goes to the proxy server — the intermediary device between the desktop computer and the internet. The proxy server pulls the resource and relays it to the user, by caching the new data and using it for future requests made to the same server.
In this guide, you will learn how to set up, configure, and install a Squid Proxy server on CentOS 7.
Prerequisites
Steps for Installing Squid Proxy on CentOS
Step 1: Refresh CentOS Software Repositories
Ensure that you are working with the latest software version by updating your repositories.
Launch a terminal window, and enter the following:
sudo yum -y updateStep 2: Install Squid Package on CentOS
To install Squid, type:
yum -y install squidNow start Squid by entering the following command:
systemctl start squidTo set up an automatic start at boot:
systemctl enable squidReview the status of the service, use:
systemctl status squidIn 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.conf2. 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 transparent3. 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 all4. Restart the Squid service by entering:
sudo systemctl restart squidConfigure Squid Client
The Squid proxy server is now configured. To configure the client server switch to your client machine and open your web browser.
If you’re using Firefox, you can find the proxy settings under:
Menu > Options > Network Settings > Settings
Select the radio button for Manual proxy configuration.
Use the IP address for the system hosting your Squid proxy.
To test, you can visit https://whatismyipaddress.com/ip-lookup. Your IP address appears as the proxy server’s IP address.
Create an Access Control List (ACL)
For connections outside the proxy server’s local network, you need to configure the Access Control Lists (ACL). This may be necessary if you get a ‘refused to connect’ error.
To solve this problem, simply add to your list of safe ports with a new ACL entry.
Note: After each of the following steps, you should save and exit, then restart the Squid service to apply the new configuration.
Edit the /etc/squid/squid.conf file once again. Add a new line as follows:
acl localnet src 192.166.0.10This will create a rule that only allows the system at this IP address to connect.
Comment the line to identify the rule. Text after the # sign is ignored by Squid.
acl localnet src 192.166.0.10 # test computerYou can specify a range of IP address as follows:
acl localnet src 192.166.0.10/30Open Squid Proxy Ports
To open a specific port, add the following:
acl Safe_ports port 123 # Custom portTo save changes, restart Squid:
systemctl restart squidSet Up Proxy Authentication
Squid offers basic authentication alongside supporting other types of authentication.
First, install httpd-tools with the following command:
yum -y install httpd-toolsWith the tool installed, create the new file:
touch /etc/squid/passwd && chown squid /etc/squid/passwdTo create the password, use this command:
htpasswd /etc/squid/passwd newuserExchange the ‘newuser‘ with your user name.
The system will prompt you to enter and confirm a password for ‘newuser.’
Restart the proxy service and re-open your browser by inserting:
systemctl restart squidEdit the /etc/squid/squid.conf file, and add the following command lines:
auth_param basic program /usr/lib64/squid/basic_ncsa_auth /etc/squid/passwd
auth_param basic children 5
auth_param basic realm Squid Basic Authentication
auth_param basic credentialsttl 2 hours
acl auth_users proxy_auth REQUIRED
http_access allow auth_usersFrom now on when you connect to the Linux proxy server, you will see a prompt for your username and password. Any unauthenticated person will be stopped by an error message.
How to Block Websites with Squid Proxy
1. Create and edit a new text file /etc/squid/blocked.acl by entering:
sudo vi /etc/squid/blocked.acl2. In this file, add the websites to be blocked, starting with a dot:
.facebook.com
.twitter.com
The dot specifies to block all subsites of the main site.
3. Open the /etc/squid/squid.conf file again:
sudo vi /etc/squid/squid.conf4. Add the following lines just above your ACL list:
acl blocked_websites dstdomain “/etc/squid/blocked.acl”http_access deny blocked_websitesConclusion
In this tutorial, you learned how to install, configure and secure a Squid HTTP Proxy server.
Squid improves processing time and streamlines bandwidth use quickly through its unique caching power. In its accelerator mode, your server can work with impressive speed. It significantly enhances your network’s performance, giving your system a competitive edge.
How to Install Squid Proxy Server on CentOS 7
Squid is a popular open source web proxy server that can be used for a variety of purposes such as speeding up web browsing, filtering web content, and providing secure access to the Internet. In this tutorial, we will show you how to install and configure Squid proxy server on CentOS 7.
Prerequisites
Before you begin with this guide, you should have a separate, non-root user account with sudo privileges set up on your server. You can learn how to set up such a user account by following our initial server setup guide for CentOS 7.
Step 1 — Installing Squid
The first step is to install Squid on your server. Squid is available in the default CentOS 7 repositories. To install it, type the following command:
sudo yum install squid
Once the installation is complete, you can start the Squid service and enable it to start at boot time with the following commands:
sudo systemctl start squid
sudo systemctl enable squid
Step 2 — Configuring Squid
The Squid configuration file is located at /etc/squid/squid.conf. Before making any changes to the configuration file, it is recommended to make a backup of the original file:
sudo cp /etc/squid/squid.conf /etc/squid/squid.conf.bak
Now, open the configuration file in your text editor:
sudo nano /etc/squid/squid.conf
The default configuration file is well commented and should be self-explanatory. You can modify the configuration according to your needs. For example, if you want to allow access to the proxy server from a specific IP address or subnet, you can add the following line:
acl allowed_hosts src 192.168.1.0/24
Once you have made the necessary changes, save and close the file. Then, restart the Squid service for the changes to take effect:
sudo systemctl restart squid
Step 3 — Testing Squid
At this point, Squid should be up and running. To test it, you can use the curl command to download a web page through the proxy server:
curl -x http://your_server_ip:3128 http://example.com
If everything is working correctly, you should see the HTML source code of the example.com web page in the terminal.
Conclusion
In this tutorial, you have learned how to install and configure Squid proxy server on CentOS 7. You can now use Squid to speed up web browsing, filter web content, and provide secure access to the Internet.
