Transparent Proxy with Linux and Squid mini-HOWTO: Transparent Proxy With Bridging

7. Transparent Proxy With Bridging

Warning, this is really esoteric stuff. If you need it, you'll know. If not, skip this section. Thanks to Lewis Shobbrook (lshobbrook@fasttrack.net.au) for contributing to this section.

If you are trying to setup a transparent proxy on a Linux machine that has been configured as a bridge, you will need to add one additional command. Specifically, you need to explicitly allow connections to the machine on port 3128 (or any other port squid is listening on), otherwise the machine will just forward them over to the other interface like a good little bridge. Here's the magic words:

iptables -A INPUT -i interface -p tcp -d your_bridge_ip -s local-network --dport 3128 -m state --state NEW,ESTABLISHED -j ACCEPT

Replacing interface with the interface that corresponds to your_bridge_ip (typically eth0 or eth1). First time bridge users should also note that you'll probably want to repeat the same command with ``3128'' replaced by ``telnet'' if you want to administer your bridge remotely.

Next Previous Contents