From owner-freebsd-security Mon Jul 16 7:56:40 2001 Delivered-To: freebsd-security@freebsd.org Received: from whale.sunbay.crimea.ua (whale.sunbay.crimea.ua [212.110.138.65]) by hub.freebsd.org (Postfix) with ESMTP id 83EC437B401 for ; Mon, 16 Jul 2001 07:56:16 -0700 (PDT) (envelope-from ru@whale.sunbay.crimea.ua) Received: (from ru@localhost) by whale.sunbay.crimea.ua (8.11.2/8.11.2) id f6GEtTa60010; Mon, 16 Jul 2001 17:55:29 +0300 (EEST) (envelope-from ru) Date: Mon, 16 Jul 2001 17:55:29 +0300 From: Ruslan Ermilov To: Darren Reed Cc: Crist Clark , freebsd-security@FreeBSD.ORG Subject: Re: FW: Small TCP packets == very large overhead == DoS? Message-ID: <20010716175529.A51681@sunbay.com> Mail-Followup-To: Darren Reed , Crist Clark , freebsd-security@FreeBSD.ORG References: <3B4A53D7.287F47AF@globalstar.com> <200107100938.TAA13064@caligula.anu.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200107100938.TAA13064@caligula.anu.edu.au>; from avalon@coombs.anu.edu.au on Tue, Jul 10, 2001 at 07:38:59PM +1000 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Tue, Jul 10, 2001 at 07:38:59PM +1000, Darren Reed wrote: > In some mail from Crist Clark, sie said: > > > > The TCP segment is everything in the IP payload. An SYN segment is a > > TCP segment, but it carries no data and has a segment length of one (whee!). > > I can see that clearly in the RFC, and I think we all cab agree on that. > > However, I think that a SYN segment, which is all header, has a size greater > > than one. It looks more like 24-or-so bytes typically... or maybe it does not. > > I am looking for where (if anywhere) the specification comes out and says > > that segment "size" is the same as "length." Why isn't the MSS called the MSL > > after the RFC has gone to such pains to define "length?" > > Why can't a SYN segment be a TCP segment of length 0 ? > (with one phantom byte) > Because it is acknowledged by the other side. -- Ruslan Ermilov Oracle Developer/DBA, ru@sunbay.com Sunbay Software AG, ru@FreeBSD.org FreeBSD committer, +380.652.512.251 Simferopol, Ukraine http://www.FreeBSD.org The Power To Serve http://www.oracle.com Enabling The Information Age To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message