From: "Rob Sterenborg" <rob@sterenborg.info>
To: 'iptables' <netfilter@lists.netfilter.org>
Subject: RE: State NEW and --syn flag
Date: Tue, 20 Jul 2004 20:47:49 +0200 [thread overview]
Message-ID: <20040720184750.0B34420AB@sterenborg.info> (raw)
In-Reply-To: <200407201038.42003.Antony@Soft-Solutions.co.uk>
> > If checking for state NEW, is there any reason to also check if the
> > --syn flag is set or is it enough to just rely on state NEW ?
>
> Depends on your degree of security paranoia :)
...
> If you let through NEW packets which do not have SYN (only)
> set, then the
> result depends on the O/S on the machine they get forwarded
> to. I suggest
> http://www.insecure.org as a source of data on what different
> systems do with
> different strange flag combinations in packets they receive.
>
> One thing is almost certain - letting through NEW packets
> which don't have SYN
> set is very unlikely to result in an ESTABLISHED connection
> being created.
Thanks !
I'll be paranoid ;-)..
Gr,
Rob
prev parent reply other threads:[~2004-07-20 18:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-07-20 9:15 State NEW and --syn flag Rob Sterenborg
2004-07-20 9:38 ` Antony Stone
2004-07-20 18:47 ` Rob Sterenborg [this message]
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=20040720184750.0B34420AB@sterenborg.info \
--to=rob@sterenborg.info \
--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