From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnt Karlsen <arnt@c2i.net>
Subject: Re: port forwarding problem
Date: Wed, 29 Jan 2003 02:21:19 +0100
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On Tue, 28 Jan 2003 16:14:09 +0800 (PHT), 
<oarojo@intermediacorp.com> wrote in message 
<24307.192.168.0.1.1043741649.squirrel@mail.intermediacorp.com>:

> hello guys!!! Can someone help me on my problem regarding iptables???
> 
> This has been my problem a month now.. I'm running a redhat 7.3
> firewall server with two NICs; eth0 facing the internal network
> (192.168.0.x) and eth1 facing the internet (external network). Now I
> wish to forward all traffic on eth1, port 25 to another to my mail
> server (say, 192.168.0.2). I did something like:
> 
> iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -j MASQUERADE
> iptables -A FORWARD -p tcp --dport 25 -d 192.168.0.2 -j ACCEPT
> iptables -A PREROUTING -t nat -p tcp --dport 25 -d x.x.x.x -j DNAT
>  --to 192.168.0.2
> 
> Now when i used to test SMTP connection thru telnetting from another
> server... say:
> 
> #telnet xxx.xxx.xxx.xxx 25
> 
> It just stucked in there doesn't continue...
> 
> using nmap on my firewall:
> 
> #nmap xxx.xxx.xxx.xxx -p 25
> 
> it says that port 25 is filtered...
> 
> 
> Is there anything wrong with my iptable rules? I would really
> appreciate if you can send me your help... thanks!

..a stab in the dark: 'cat /proc/sys/net/ipv4/ip_forward' says?

-- 
..med vennlig hilsen = with Kind Regards from Arnt... ;-)
...with a number of polar bear hunters in his ancestry...
  Scenarios always come in sets of three: 
  best case, worst case, and just in case.