How to Setup Squid Proxy Server on Linux CentOS 6.3

This post describes the steps to setup a Squid 3 Proxy Server on CentOS6.3. Squid service plays two main roles which mainly act as a caching proxy server between the user and the web. Second role, squid also regularly used as a content accelerator, or reverse proxy, intercepting requests to a server and using a cached version of the page to serve the request. Follow below steps to install and configure squid.

1. Run yum install :

[root@centos63 ~]# yum install squid -y
Loaded plugins: fastestmirror, presto, priorities
Loading mirror speeds from cached hostfile
 * base: centos.ipserverone.com
 * extras: centos.ipserverone.com
 * updates: centos.ipserverone.com
CentOS6.3-Repository                                                         | 4.0 kB     00:00 ...
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package squid.i686 7:3.1.10-9.el6_3 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

====================================================================================================
 Package             Arch               Version                         Repository             Size
====================================================================================================
Installing:
 squid               i686               7:3.1.10-9.el6_3                updates               1.7 M

Transaction Summary
====================================================================================================
Install       1 Package(s)

Total download size: 1.7 M
Installed size: 5.7 M
Downloading Packages:
Setting up and reading Presto delta metadata
Processing delta metadata
Package(s) data still to download: 1.7 M
squid-3.1.10-9.el6_3.i686.rpm                                                | 1.7 MB     00:14
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : 7:squid-3.1.10-9.el6_3.i686                                                      1/1
  Verifying  : 7:squid-3.1.10-9.el6_3.i686                                                      1/1

Installed:
  squid.i686 7:3.1.10-9.el6_3

Complete!

2. Configure main squid configuration file. Use vi to edit :

[root@centos63 ~]# vi /etc/squid/squid.conf

3. Add internal network name into the IP networks list where browsing should be allowed. In this example, your internal network name is ehowstuff :

# Example rule allowing access from your local networks.
# Adapt to list your (internal) IP networks from where browsing
# should be allowed
acl localnet src 10.0.0.0/8     # RFC1918 possible internal network
acl localnet src 172.16.0.0/12  # RFC1918 possible internal network
acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
acl localnet src fc00::/7       # RFC 4193 local private network range
acl localnet src fe80::/10      # RFC 4291 link-local (directly plugged) machines
acl ehowstuff src 192.168.1.0/24    # Your internal network

4. Add ehowstuff network in the ACL section list IP networks where browsing should be allowed :

http_access allow localnet
http_access allow localhost
http_access allow ehowstuff

5. Make sure squid proxy port is uncomment. You can change the proxy port to any available port here. As an example, other available port is 8080.

# Squid normally listens to port 3128
http_port 3128

6. Start squid service :

[root@centos63 ~]# service squid start
Starting squid:                                            [  OK  ]

7. Configure at proxy setting at client’s browser as below :