A made a little patch to make Pound capable of transparent
proxying under Linux 2.6.
Web servers on backends can log the original IP and/port of
clients without the need to parse X-Forwarded-for headers.
It can be a solution for you, if you want to restrict
clients by IP and header parsing is not applicable for any
reason, and you want to increase security by checking http
stream with a proxy.
If transparent proxying is enabled in Pound backends believe
that they are communicating directly with clients.
More information is available at http://poundtp.freeweb.hu