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From: Ben <bench@silentmedia.com>
To: lartc@vger.kernel.org
Subject: Re: [LARTC] port forwarding to different servers with nat
Date: Thu, 04 Sep 2003 17:28:07 +0000	[thread overview]
Message-ID: <marc-lartc-106269660005719@msgid-missing> (raw)
In-Reply-To: <marc-lartc-106269521803965@msgid-missing>

Okay. So let's say it's fred and wilma, sharing the external dns name
"external". So I would forward to fred and wilma like so:

iptables -t nat -A PREROUTING -d external -p tcp --dport 80 -j DNAT --to fred
iptables -t nat -A PREROUTING -d external -p tcp --dport 8080 -j DNAT --to wilma

That makes sense to me. But how do the return packets get rewritten?

iptables -t nat -A POSTROUTING -s wilma -j SNAT --to external
iptables -t nat -A POSTROUTING -s fred -j SNAT --to external

...seems wrong. Or does it work just fine? (I can't test it right now, 
unfortuantely....)

On Thu, 4 Sep 2003, Lawrence MacIntyre wrote:

> So for example, you want one machine (call it fred) to have a web server
> on port 80, and another (call it wilma) to have a web server on port
> 8080?
> 
> Simply forward port 80 to fred:80 and port 8080 to wilma:80. 
> Alternately, you can run wilma's webserver on port 8080 and forward port
> 8080 to wilma:8080.
> 
> On Thu, 2003-09-04 at 13:05, Ben wrote:
> > Hey guys, here's a basic problem I cannot seem to figure out. I've got a 
> > box doing NAT for some servers and masquarading for a bunch of other 
> > desktops. The way I have it working, I need to the give my NAT box one 
> > IP number for the masquarding, and then one additional IP number for each 
> > server it NATs for. That's a waste; I'd like to give the NAT box one IP 
> > for all servers, and then forward to the correct server based on port. 
> > (Yes, that implies none of the servers can run services on the same port, 
> > and I'm fine with that.)
> > 
> > It seems like this should be a pretty common scenario, but I haven't been 
> > able to get it working and I haven't seen any examples online. I'm sure 
> > *somebody* has it working.... would that person please share the wealth?
> > 
> > 
> > _______________________________________________
> > LARTC mailing list / LARTC@mailman.ds9a.nl
> > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
> 


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/

  parent reply	other threads:[~2003-09-04 17:28 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-09-04 17:05 [LARTC] port forwarding to different servers with nat Ben
2003-09-04 17:16 ` Lawrence MacIntyre
2003-09-04 17:28 ` Ben [this message]
2003-09-04 22:35 ` trepo 
2003-09-05  6:58 ` Dancer Vesperman
2003-09-05 13:50 ` Lawrence MacIntyre

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