From: Sumit <sumit@elitecore.com>
To: netfilter-devel@lists.netfilter.org
Subject: ipt_unclean query
Date: Sat, 08 Apr 2006 13:36:41 +0530 [thread overview]
Message-ID: <44376F11.4000804@elitecore.com> (raw)
Hi Devs,
After making an unclean DROP ruleset I got "not-working" complains form
some of my clients who using specific stock-trading application.
Simply looking to dmesg I found there are few message states that
ipt_unclean: TCP flags bad: 0x0015
This message mean unclean match is dropping tcp packet with ACK,RST,
and FIN flags. This I confirm with ipt_unclean.c code
As per RFC793 (TCP)
... ... ...
In all states except SYN-SENT, all reset (RST) segments are validated by
checking their SEQ-fields. A reset is valid if its sequence number is
in the window.
... ... ...
Then is there any significance of dropping ACK+RST+FIN combination?
Happy Netfiltering,
--
_____ __ __ ____ ____ __ ______
/\ ___\ /\ \ /\ \ /\ \ \/ /\ \ /\ \ /\__ _\
\ \ ____\ \ \ \\_| \\ \ \_ /\ \ \\ \ \\__ \ \/
\//\___ \ \ \______ / \ \__\ \ \__\\ \__\ \ \__\
\/_____/ \/_____ / \/__/ \/__/ \/__/ \/__/
next reply other threads:[~2006-04-08 8:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-04-08 8:06 Sumit [this message]
2006-04-08 16:44 ` ipt_unclean query Phil Oester
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