[SOLVED] iptables for transparent proxy

b56r1 · 10-28-2013, 04:52 AM

Hi all. I'm implementing transparent proxy in a Linux machine. I went through the Linux's documentation regarding Tproxy found in the Linux source folder (Linux/Documentation/networking/tproxy.txt).

What is the use of this iptable rule below having the socket option? What it really does? I read in some forums that this rule is to avoid sending the packets to tproxy twice. What it really means?

iptables -t mangle -A PREROUTING -p tcp -m socket -j DIVERT

Thank you.

Ser Olmy · 11-03-2013, 02:10 PM

The "socket" match looks for matching local sockets with the IP_TRANSPARENT option set for packets with non-local destination addresses.

Take a look at pages 4 and 5 of this PDF document.

b56r1 · 11-08-2013, 03:43 AM

Thanks for reply and pdf link Ser Olmy