public inbox for netdev@vger.kernel.org
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Denys Fedoryshchenko <denys@visp.net.lb>
Cc: netdev@vger.kernel.org, netfilter@vger.kernel.org
Subject: Re: conntrack, NAT and icmp echo reply
Date: Thu, 11 Oct 2012 11:57:10 +0200	[thread overview]
Message-ID: <1349949430.21172.8435.camel@edumazet-glaptop> (raw)
In-Reply-To: <e457eb3b6f3e357c3681c7af5f504161@visp.net.lb>

On Thu, 2012-10-11 at 12:41 +0300, Denys Fedoryshchenko wrote:
> Hi all
> 
> I have NAT box, with very simple rule
> iptables -t nat -I POSTROUTING -s 10.0.0.0/8 -j MASQUERADE
> It can be SNAT also, and it works fine, as NAT.
> 
> When i generate icmp _reply_ packet, to some host
> hping -I ppp0 -1 --icmptype 0 8.8.8.8
> 
> It will pass the box, and will exit it without NAT, e.g. with original 
> IP 10.x.x.x
> on outgoing interface, which is not expected behavior IMHO.
> Is it a bug or feature?
> 

It depends, -s 10.0.0.0/8 wont match the rule if the source address
should be 198.23.44.55 I guess ?

I would try the more obvious

iptables -t nat -I POSTROUTING -o device -j MASQUERADE




  reply	other threads:[~2012-10-11  9:57 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-11  9:41 conntrack, NAT and icmp echo reply Denys Fedoryshchenko
2012-10-11  9:57 ` Eric Dumazet [this message]
2012-10-11 10:02   ` Denys Fedoryshchenko
2012-10-12  5:13     ` Vigneswaran R
2012-10-12  6:59       ` Denys Fedoryshchenko
2012-10-12 12:41         ` Jozsef Kadlecsik

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=1349949430.21172.8435.camel@edumazet-glaptop \
    --to=eric.dumazet@gmail.com \
    --cc=denys@visp.net.lb \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter@vger.kernel.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