Linux Netfilter discussions
 help / color / mirror / Atom feed
From: Christian Seberino <seberino@spawar.navy.mil>
To: Patrick Schaaf <bof@bof.de>
Cc: netfilter@lists.samba.org
Subject: Re: how is this stuff getting thru default deny iptables firewall?....
Date: Thu, 27 Jun 2002 00:21:44 -0700	[thread overview]
Message-ID: <20020627002144.B13910@spawar.navy.mil> (raw)
In-Reply-To: <20020623095351.M5183@oknodo.bof.de>; from bof@bof.de on Sun, Jun 23, 2002 at 09:53:51AM +0200

Patrick

Wow, were getting into the deep nitty gritty now!...


> 	   The "nat" table is NOT consulted for "second or more"
> 	   packet of an existing conntrack.

I needed to sit down and get a glass of water for this one.
This is one to lose sleep over....

I thought /ALL/ packets first went thru -t nat PREROUTING
and then -t filter and then -t nat POSTROUTING.

"of an existing conntrack" seems to be the same
as an ESTABLISHED packet....

*If I did not explicitly allow ESTABLISHED & RELATED
packets thru FORWARD chain then how can they pass?!?*

It almost seems like there is some hard coded ACCEPT
rules implied in iptables that you can't turn off!?!???

Is this correct to summarize?

0. conntrack = ESTABLISHED 

1. ESTABLISHED packets don't have to deal with -t nat table.

2. Somehow I don't have to ACCEPT these ESTABLISHED packets
   for them to go thru?!?!?

Chris


-- 
_______________________________________

Dr. Christian Seberino
SPAWAR Systems Center San Diego
Code 2363
53560 Hull Street
San Diego, CA 92152-5001
U.S.A.

Phone: (619) 553-7940
Fax:   (619) 553-2836
Email: seberino@spawar.navy.mil
_______________________________________


  reply	other threads:[~2002-06-27  7:21 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-06-22 17:30 how is this stuff getting thru default deny iptables firewall? Christian Seberino
2002-06-22 17:38 ` Antony Stone
2002-06-23  7:13   ` Christian Seberino
2002-06-23  7:53     ` Patrick Schaaf
2002-06-27  7:21       ` Christian Seberino [this message]
2002-06-27  7:37         ` Patrick Schaaf
2002-07-09 19:08           ` Christian Seberino
2002-06-23  8:07     ` Antony Stone
2002-06-27  7:14       ` Christian Seberino
2002-06-27  7:28         ` Patrick Schaaf
  -- strict thread matches above, loose matches on Subject: below --
2002-06-22 21:43 James T. Moore
2002-06-23  7:13 ` Christian Seberino
2002-07-09 19:43 j davis
2002-07-09 21:41 ` Christian Seberino
2002-07-09 21:43 ` Christian Seberino
     [not found]   ` <Pine.LNX.4.33.0207101903030.1723-100000@dodobirdy.nestac.com>
2002-07-10 16:34     ` Christian Seberino

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=20020627002144.B13910@spawar.navy.mil \
    --to=seberino@spawar.navy.mil \
    --cc=bof@bof.de \
    --cc=netfilter@lists.samba.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