redirecting outgoing traffic

[warlord at MIT.EDU (Derek Atkins)]

You cannot use IPCHains to forward from port A on machine A to port B
on machine B.  I recommend you use a 'tcpforward' application to perform
that task.  Yes, it means packets take longer, as they have to go up the
stack and then come down.  But it's a known-to-work solution.

Alternatively, you can try to use ssh's port-forwarding capabilities
to forward that port for you.

-derek

Kevin Falcone <kevinfal at seas.upenn.edu> writes:

> I am trying to configure the firewall machine on my network to
> redirect all outgoing traffic headed for port 25 on a remote machine
> to a different port.  Port 2525 is an ssh tunneled connection to the
> network with an smtp server that I relay off of.  I would like to
> redirect all of my outgoing to smtp traffic to that high port.  
> 
> I have tried variations on the following with no luck
> 
> /sbin/ipchains -A output -p tcp -j REDIRECT 25 -d localhost 2025
> 
> I am told that I can't redirect on output or forward.
> 
> Is there a way to do this, or am I stuck with my particularly hackish
> perl replacement for sendmail.
> 
> -kevin
> 
> -- 
> Kevin Falcone <kevinfal at seas.upenn.edu>
> 
> Give a man a fish and you feed him for a day; give him a freshly-charged
> Electric Eel and chances are he won't bother you for anything ever again
> -
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-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/      PP-ASEL      N1NWH
       warlord at MIT.EDU                        PGP key available
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