From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mr Ritter <netfilter@candlefire.org>
Subject: Re: Port forwarding question
Date: Thu, 21 Sep 2006 14:25:04 -0600
Message-ID: <4512F520.6010104@candlefire.org>
References: <200609211555.39634.dyioulos@firstbhph.com>
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To: Dimitri Yioulos <dyioulos@firstbhph.com>, netfilter@lists.netfilter.org

Greetings,

Dimitri Yioulos wrote:
> Noob, question:
> 
> I want to allow a vendor to access a piece of equipment on our LAN  
> (192.168.100.46) through port 4000 from outside via a server in our 
> DMZ (www.xxx.yyy.zzz).  While I should know how to do this, I'm not 
> 100% sure.  Can someone help?

DNAT.

for example:
iptables -t nat -A PREROUTING -d www.xxx.yyy.zzz -i eth1 -p tcp --dport 
4000 -j
DNAT --to 192.168.100.46
iptables -t filter -A INETIN -d 192.168.100.46 -p tcp --dport 4000 -j ACCEPT


> Oh, and separately, how would I allow that access only through the 
> vendor's ip address, if that were the way I decided to go?

for example:
iptables -t nat -A PREROUTING -s 1.2.3.4 -d www.xxx.yyy.zzz -i eth1 -p 
tcp --dport 4000 -j DNAT --to 192.168.100.46


Regards,

--
Ritter