netfilter.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: netfilter@buglecreek.com
To: Pascal Hambourg <pascal.mail@plouf.fr.eu.org>
Cc: netfilter@vger.kernel.org
Subject: Re: Correct Chains to Apply Rules
Date: Tue, 17 May 2011 15:50:45 -0600	[thread overview]
Message-ID: <1305669045.20717.1453045045@webmail.messagingengine.com> (raw)
In-Reply-To: <4DD2E89F.30801@plouf.fr.eu.org>

OK.  Thanks.  So to block/allow traffic from network A to/from network B
I would apply my rules to the FORWARD chain using a source/destination. 
The INPUT and OUTPUT chains on eth0 and eth1 are only for traffic bound
for the firewall/router box itself? 

On Tue, 17 May 2011 23:29 +0200, "Pascal Hambourg"
<pascal.mail@plouf.fr.eu.org> wrote:
> Hello,
> 
> netfilter@buglecreek.com a écrit :
> > 
> > In the following scenario.  Someone makes a new HTTP request from the
> > Internet that is allowed inbound on eth0 and goes out of the eth1
> > interface to the HTTP server in the server network. 
> > The HTTP server in the server network sends the response to the original
> > requester.  
> > 
> > Does the response ever hit the INPUT chain of ETH1?
> 
> No.
> 
> > Or does it immediately go to the FORWARD chain
> 
> Yes.
> 
> > and out the OUTPUT chain of eth0.  
> 
> No.
> The three filter chains are mutually exclusive : a packet can only go
> through one of them. Forwarded packets only go through the FORWARD chain.
> 

  reply	other threads:[~2011-05-17 21:50 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-17 21:14 Correct Chains to Apply Rules netfilter
2011-05-17 21:29 ` Pascal Hambourg
2011-05-17 21:50   ` netfilter [this message]
2011-05-17 22:06     ` Jorge Dávila
2011-05-17 22:19     ` Andrew Beverley

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=1305669045.20717.1453045045@webmail.messagingengine.com \
    --to=netfilter@buglecreek.com \
    --cc=netfilter@vger.kernel.org \
    --cc=pascal.mail@plouf.fr.eu.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;
as well as URLs for NNTP newsgroup(s).