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From: Michael Vallaly <netfilter@nolatency.com>
To: GMail Isaac Gonzalez <isaak.gonzalez@gmail.com>
Cc: netfilter@vger.kernel.org
Subject: Re: POSTROUTING SNAT only reply packets
Date: Mon, 17 Jan 2011 17:07:52 -0600	[thread overview]
Message-ID: <20110117170752.a10b99de.netfilter@nolatency.com> (raw)
In-Reply-To: <4D341710.60509@gmail.com>


Have you tried the RAWNAT modules from xtables-addons? 

<snip>
iptables -A OUTPUT -s $ORIG_IP -j RAWSNAT --to-source $NEW_IP
</snip>

I've used RAWSNAT in the past, with fairly good success.

-Mike

On Mon, 17 Jan 2011 11:16:48 +0100
GMail Isaac Gonzalez <isaak.gonzalez@gmail.com> wrote:

> Hi,
> 
> I need to modify the reply packets of one web server to allow the 
> connections between a webserver and client using a load balancer.
> 
> The client connections goes to a load balancer, the load balancer 
> forwards the connection to a one web server changing the destination ip, 
> the web server anwser the client with it's own ip address without 
> passing again for the load balancer. In order to stablish the 
> connection, the client needs to receive the web server answer with the 
> correct ip address (in this case, the load balancer VIP address), in 
> other case it receives ACK that it doesn't know about it and the 
> connections is not ESTABLISHED.
> 
> I've doing some testing and seems that iptables only do SNAT on NEW 
> connections, and I need to change the ip address of replied packets. 
> Anybody know some workaround? If anobody do not know some workaround can 
> you confirm that it's not posible to do this with iptables?
> 
> I've tried the next ip tables rules and only work when I do NEW 
> connections from the web server.
> 
> -A POSTROUTING -o br0 -s WE_SERVER_ADDR -p tcp -m tcp --sport 80 --dport 
> 1024:65535 -j SNAT --to-source LOAD_BALANCER_ADDR
> 
> Thanks in advance.
> 
> Isaac González
> --
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-- 
Michael Vallaly <mvallaly@nolatency.com>

  parent reply	other threads:[~2011-01-17 23:07 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-17 10:16 POSTROUTING SNAT only reply packets GMail Isaac Gonzalez
2011-01-17 10:38 ` Gáspár Lajos
2011-01-17 10:51   ` GMail Isaac Gonzalez
2011-01-17 11:14     ` Amos Jeffries
2011-01-17 10:55   ` Giles Coochey
2011-01-17 11:07     ` GMail Isaac Gonzalez
2011-01-17 11:36     ` Jan Engelhardt
2011-01-17 11:41       ` Giles Coochey
2011-01-17 11:57         ` GMail Isaac Gonzalez
2011-01-17 12:10           ` Jan Engelhardt
2011-01-17 23:07 ` Michael Vallaly [this message]
  -- strict thread matches above, loose matches on Subject: below --
2011-01-17 10:15 Isaac González

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