Transparent Proxy

For who are curious about transparent proxy….

What is transparent proxy?

Transparent proxy from the easy point perspective is a “hidden” proxy server. Users don’t know when they access the internet, all requests will be redirect to the proxy server first. After the requests pass on the proxy server, the requests will be directed to the original site, example when you access yahoo.com, gmail.com or whatever, the requests go through proxy so no need to go to the original site location. This method will save the bandiwth and faster.

How to set it up?

For the initial task, install squid on your server (proxy server usually included on most of linux distro). Then set this setting on your squid.conf:

httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on

Then set iptables:

iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128

Make sure to match the Ethernet card, if you have eth0 then use -o eth0, eth1 will be -o eth1, and so on.