[3727] in linux-net channel archive
Re: TCP denial of service?
daemon@ATHENA.MIT.EDU (Alan Cox)
Tue Jul 16 18:24:21 1996
From: iialan@iifeak.swan.ac.uk (Alan Cox)
To: jlewis@inorganic5.fdt.net (Jon Lewis)
Date: Tue, 16 Jul 1996 09:34:35 +0100 (BST)
Cc: linux-net@vger.rutgers.edu
In-Reply-To: <Pine.LNX.3.91.960715182401.15516x-100000@inorganic5.chem.ufl.edu> from "Jon Lewis" at Jul 15, 96 06:52:05 pm
> I looked at netstat -tn, and saw lots of connections to :25 in TIME_WAIT,
> and about 10 in SYN_RECV. The ones in SYN_RECV were from another server
> of ours on another backbone providers net...and the routing was out, so
> that address was unreachable. When the routing returned, the SYN_RECV's
> went away, and sendmail was able to receive connections again. Is it
> possible to increase the number of SYN_RECV's that can stack up before
> connections start to hang?
Change the number specified in the listen() system call sendmail makes.
Alan
