From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH] Add IPv6 support to TCP SYN cookies Date: Wed, 6 Feb 2008 09:53:57 +0100 Message-ID: <20080206085357.GA1402@one.firstfloor.org> References: <47a79d64.16538c0a.5b6a.ffffb0fe@mx.google.com> <20080205155558.GA23145@one.firstfloor.org> <20080205192559.GA10573@kallisti.us> <20080205201106.GB26150@one.firstfloor.org> <20080205212335.GA11287@kallisti.us> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andi Kleen , Glenn Griffin , netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Ross Vandegrift Return-path: Received: from one.firstfloor.org ([213.235.205.2]:43314 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751187AbYBFITD (ORCPT ); Wed, 6 Feb 2008 03:19:03 -0500 Content-Disposition: inline In-Reply-To: <20080205212335.GA11287@kallisti.us> Sender: netdev-owner@vger.kernel.org List-ID: > I work at a hosting company and we see these kinds of issues in the > real world fairly frequently. I would guess maybe a monthly basis. > The servers where we have seen this are typically running RHEL 4 or 5 > kernels, so I can't really speak to how recent the kernel is in this > specific term. RHEL5 should be recent enough. > > If I can find a box that we could temporary get a kernel.org kernel > on, I'll see if I can get a real comparison together. We have > collected a few of the more effective attack tools that have been left > on compromised systems, so it wouldn't be too difficult to get some > numbers. That would be useful yes -- for different bandwidths. If the young/old heuristics do not work well enough anymore most likely we should try readding RED to the syn queue again. That used to be pretty effective in the early days. I don't quite remember why Linux didn't end up using it in fact. -Andi