From owner-freebsd-current@FreeBSD.ORG Thu May 6 12:22:10 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B6AF016A4DD; Thu, 6 May 2004 12:22:10 -0700 (PDT) Received: from gw.celabo.org (gw.celabo.org [208.42.49.153]) by mx1.FreeBSD.org (Postfix) with ESMTP id 08EAB43D31; Thu, 6 May 2004 12:22:10 -0700 (PDT) (envelope-from nectar@celabo.org) Received: from madman.celabo.org (madman.celabo.org [10.0.1.111]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "madman.celabo.org", Issuer "celabo.org CA" (not verified)) by gw.celabo.org (Postfix) with ESMTP id 97F0C54840; Thu, 6 May 2004 14:22:09 -0500 (CDT) Received: by madman.celabo.org (Postfix, from userid 1001) id 3DAD66FF36; Thu, 6 May 2004 14:22:09 -0500 (CDT) Date: Thu, 6 May 2004 14:22:09 -0500 From: "Jacques A. Vidrine" To: Andre Oppermann Message-ID: <20040506192209.GC1939@madman.celabo.org> Mail-Followup-To: "Jacques A. Vidrine" , Andre Oppermann , freebsd-current@freebsd.org, freebsd-net@freebsd.org References: <200405061846.i46Ik3Jc060969@repoman.freebsd.org> <409A8EF3.5825EF0C@freebsd.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <409A8EF3.5825EF0C@freebsd.org> X-Url: http://www.celabo.org/ User-Agent: Mutt/1.5.6i cc: freebsd-net@freebsd.org cc: freebsd-current@freebsd.org Subject: Re: Default behaviour of IP Options processing X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 May 2004 19:22:10 -0000 On Thu, May 06, 2004 at 09:16:03PM +0200, Andre Oppermann wrote: > I have just committed the attached change to ip_input() to control the > behaviour of IP Options processing. The default is the unchanged > current behaviour. > > However I want to propose to change the default from processing options > to ignoring options (or even stronger to reject them). > > The rationale is as follows. IP Options do not have any legitimate use > in todays Internet at all. For a long time now we have disabled source > routing. The remaining IP Options are RR (record route) and TS (time > stamp) which are both useless. For finding out which path a packet takes > we use traceroute instead of RR. Besides that RR is limited to the space > in the IP Options field and can possibly record only a few hops (9 IIRC). > Time stamp is useless for the same reason and since it doesn't have a > fixed and synchronized timebase it is even more so useless. > > Opinions? Discussion? Yes/Nay? Maybe you've already seen my reply to your commit, but: I would very much like to see the default be 1-ignore or 2-reject, preferably the latter. I believe your analysis is correct. I haven't been able to use record route for anything useful since around 1996--- this partially because networks became larger and partly because many systems started dropping packets with options :-) Timestamp is also somewhat esoteric. But the point is that enabling these options should require a concious decision by users. Those who want them can turn them on ... most users probably don't know these options even exist, and for them I think it is better to have them default off. Cheers, -- Jacques Vidrine / nectar@celabo.org / jvidrine@verio.net / nectar@freebsd.org