From owner-freebsd-security@FreeBSD.ORG Wed Apr 21 17:30:55 2004 Return-Path: Delivered-To: freebsd-security@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 610C916A4CE for ; Wed, 21 Apr 2004 17:30:55 -0700 (PDT) Received: from smtp3.sentex.ca (smtp3.sentex.ca [64.7.153.18]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0E8CE43D2D for ; Wed, 21 Apr 2004 17:30:55 -0700 (PDT) (envelope-from mike@sentex.net) Received: from avscan2.sentex.ca (avscan2.sentex.ca [199.212.134.19]) by smtp3.sentex.ca (8.12.11/8.12.10) with ESMTP id i3M0UpSE095392; Wed, 21 Apr 2004 20:30:51 -0400 (EDT) (envelope-from mike@sentex.net) Received: from localhost (localhost [127.0.0.1]) by avscan2.sentex.ca (Postfix) with ESMTP id D7E2059C9A; Wed, 21 Apr 2004 20:30:52 -0400 (EDT) Received: from avscan2.sentex.ca ([127.0.0.1]) by localhost (avscan2.sentex.ca [127.0.0.1]) (amavisd-new, port 10024) with SMTP id 92108-12; Wed, 21 Apr 2004 20:30:52 -0400 (EDT) Received: from lava.sentex.ca (pyroxene.sentex.ca [199.212.134.18]) by avscan2.sentex.ca (Postfix) with ESMTP id C08D359C96; Wed, 21 Apr 2004 20:30:52 -0400 (EDT) Received: from simian.sentex.net (simeon.sentex.ca [192.168.43.27]) by lava.sentex.ca (8.12.11/8.12.11) with ESMTP id i3M0UpIq045972; Wed, 21 Apr 2004 20:30:52 -0400 (EDT) (envelope-from mike@sentex.net) Message-Id: <6.0.3.0.0.20040421202553.08107ad0@209.112.4.2> X-Sender: mdtpop@209.112.4.2 (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 6.0.3.0 Date: Wed, 21 Apr 2004 20:32:32 -0400 To: freebsd-security@freebsd.org From: Mike Tancsa In-Reply-To: <4086F156.7040808@comcast.net> References: <6.0.3.0.0.20040420144001.0723ab80@209.112.4.2> <200404201332.40827.dr@kyx.net> <20040421111003.GB19640@lum.celabo.org> <6.0.3.0.0.20040421121715.04547510@209.112.4.2> <20040421165454.GB20049@lum.celabo.org> <6.0.3.0.0.20040421132605.0901bb40@209.112.4.2> <48FCF8AA-93CF-11D8-9C50-000393C94468@sarenet.es> <6.0.3.0.0.20040421161217.05453308@209.112.4.2> <75226E9B-93D3-11D8-90F9-003065ABFD92@mac.com> <4086E522.7090303@comcast.net> <20040421214445.GX476@seekingfire.com> <4086EED7.3070808@comcast.net> <4086F156.7040808@comcast.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Virus-Scanned: by amavisd-new X-Virus-Scanned: by amavisd-new at (avscan2) sentex.ca Subject: Re: Other possible protection against RST/SYN attacks (was Re: TCP RST attack X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Security issues [members-only posting] List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Apr 2004 00:30:55 -0000 At 06:10 PM 21/04/2004, Gary Corcoran wrote: >>In any event, it still seems like a TTL of 255 is overkill for this >>application... > >Unless, of course, you want to only accept packets with TTL >of 255. This might be fine when both ends are setup to work >this way. Yes, but thats the whole point of it. By having the 2 BGP speakers *only* accept packets that have a TTL of 255, you are safe to bet it has not come across another router as no one has decremented the TTL value. ---Mike