Linux Netfilter discussions
 help / color / mirror / Atom feed
From: Willi Mann <newsletters@wm1.at>
To: netfilter@lists.netfilter.org, jal@mcs.le.ac.uk
Subject: Re: De-SNAT-ing and DNAT
Date: Tue, 25 Feb 2003 20:23:14 +0100	[thread overview]
Message-ID: <3E5BC2A2.50903@wm1.at> (raw)
In-Reply-To: <20030225180802.26030.80793.Mailman@kashyyyk>

I'm sure, but I would say based on my experience, that you will not see 
the packets that go into the other direction.
I haven't tried but maybe you can use the LOG-target in PRE/POSTROUTING. 
You will see which source and destination the packets have.


Willi

>--__--__--
>
>Message: 5
>Date: Tue, 25 Feb 2003 16:59:57 +0000 (GMT)
>From: "J. A. Landamore" <jal@mcs.le.ac.uk>
>Reply-To: "J. A. Landamore" <jal@mcs.le.ac.uk>
>Subject: De-SNAT-ing and DNAT
>To: netfilter@lists.netfilter.org
>
>Please excuse my ignorance with this, but I'm trying to pick the bones out of an 
>iptables configuration that has been dropped in my lap.
>
>I have a lan of machines on a 192.168. network with an iptables box to the real 
>world.  If I apply SNAT I can map all the internal addresses to the one real 
>world facing assigned address.  I assume that when packets come back they are 
>"de-SNAT"ed before passing back onto the private lan, and that this happens in 
>the "PREROUTING" path.  My question is, does the "de-SNAT" happen before or 
>after the "PREROUTING" DNAT?
>
>Why, because I need to make a DNAT decision based on the original _source_ 
>address, i.e. which machine originally sourced the packet.
>
>Thanks for your help
>
>John Landamore
>
>
>  
>



       reply	other threads:[~2003-02-25 19:23 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20030225180802.26030.80793.Mailman@kashyyyk>
2003-02-25 19:23 ` Willi Mann [this message]
2003-02-25 16:59 De-SNAT-ing and DNAT J. A. Landamore
2003-02-25 19:03 ` Cedric Blancher

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=3E5BC2A2.50903@wm1.at \
    --to=newsletters@wm1.at \
    --cc=jal@mcs.le.ac.uk \
    --cc=netfilter@lists.netfilter.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox