How to install Squid Proxy Server on CentOS 6.3/Redhat

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.
Step 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!

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

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

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

# 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 howtolinux src 192.168.1.0/24    # Your internal network

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

http_access allow localnet
http_access allow localhost
http_access allow howtolinux

Step 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

Step 6. Start squid service :

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

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