Squid is basically internet connection sharing server as well we can monitor the net access and control also.

  It does require at least 2 Ethernet card.

      Ex:       eth0: 122.169.108.70  (ISP )

                     255.255.255.0

                     122.169.108.1

                     59.144.127.16

                     59.144.127.17

                eth1: 192.168.30.1     (Local Network)

                     255.255.255.0

  # packages required

     # rpm –qa squid

    # vi /etc/squid/squid.conf

    Remove comment “#” from below lines.

    http_port 3128

     or

    http_port 3128 transparent

  (if you wish to add rule for redirecton of all clients ports no 80)

   cache_dir ufs /var/spool/squid 100 16 256  (LINE NO 993)

   Access_log /var/log/squid/access.log   ( Line no 1079)

   cache_log /var/log/squid/cache.log    ( Line no 1087)

   acl our_networs src 192.168.0.0/21  (as per your enviourment)

   http_access allow our_networks  (line no 2524)

   visible_hostname  stn2  (not required in new squid version)

   (line no 2843)

   :wq

   # vi /etc/sysctl.conf

    net.ipv4.ipforward = 1

   (By default its 0)

  (to enable swap directory)

 # squid –z

 After small changes in squid.conf file read the kernel

# squid –k reconfigure

# sysctle –p

# service squid restart