How to install Squid Proxy server on CentOS 5 Linux server

Squid proxy server is primarily designed to run on Linux / Unix-like type systems. Squid is known ad high-performance proxy caching server for http Web clients, it is compatible with HTTP FTP, gopher, and HTTP data objects. Unlike other traditional caching servers or software, Squid can handles all requests in a single, non-blocking, I/O-driven process. Squid keeps especially hot objects store in CACHE MEMORY, caches DNS lookups, supports non-blocking DNS lookups, and implements negative caching of failed requests.




Install Squid proxy server on CentOS 5.X / RedHat 5



You can use yum command as follows for installing Squid Automatically from internet




# yum install squid



Output:




Loading "installonlyn" plugin
Setting up Install Process
Setting up repositories
Reading repository metadata in from local files
Parsing package install arguments
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Package squid.i386 7:2.6.STABLE6-4.el5 set to be updated
--> Running transaction check

Dependencies Resolved

=============================================================================
 Package                 Arch       Version          Repository        Size
=============================================================================
Installing:
 squid                   i386       7:2.6.STABLE6-4.el5  updates           1.2 M

Transaction Summary
=============================================================================
Install      1 Package(s)
Update       0 Package(s)
Remove       0 Package(s)        

Total download size: 1.2 M
Is this ok [y/N]: y
Downloading Packages:
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing: squid                        ######################### [1/1]

Installed: squid.i386 7:2.6.STABLE6-4.el5
Complete!


Basic Configuration of Squid:


Configuration file of Squid located at /etc/squid/squid.conf. Edit this  file using a text editor:


# vi /etc/squid/squid.conf


At least you need to modify or define ACL (access control list) to work with squid. Squid defaults port is TCP 3128. Following example ACL allowing access from your local networks 192.168.0.0/24 and 192.168.10.0/24(Change with your network). Make sure your  Local network is same as mentioned above otherwise edit it you’re your requirement :


acl our_networks src 192.168.o.0/24 192.168.10.0/24
http_access allow our_networks


Save and close the file. Start squid proxy server:

# chkconfig squid on

# /etc/init.d/squid start


Output:


init_cache_dir /var/spool/squid... Starting squid: .       [  OK  ]


Verify port 3128 is open:


# netstat -tulpn | grep 3128


Output:


tcp        0      0 0.0.0.0:3128                0.0.0.0:*                   LISTEN      2



Open TCP port 3128


Finally make sure iptables is allowing to access squid proxy server. Just open /etc/sysconfig/iptables file:


# vi /etc/sysconfig/iptables


Append configuration:


-A RH-Firewall-1-INPUT -m state --state NEW,ESTABLISHED,RELATED -m tcp -p tcp --dport 3128 -j ACCEPT


Restart iptables based firewall:


# /etc/init.d/iptables restart

Output:


Flushing firewall rules:                                   [  OK  ]

Setting chains to policy ACCEPT: filter                    [  OK  ]

Unloading iptables modules:                                [  OK  ]

Applying iptables firewall rules:                          [  OK  ]

Loading additional iptables modules: ip_conntrack_netbios_n[  OK  ]


Client configuration


Open a webbrowser > Tools > Internet option > Network settings > and setup Squid server IP address and port # 3128.