From owner-freebsd-security Fri Jul 5 21:44:19 2002 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 53E5737B400 for ; Fri, 5 Jul 2002 21:44:17 -0700 (PDT) Received: from wrath.cs.utah.edu (wrath.cs.utah.edu [155.99.198.100]) by mx1.FreeBSD.org (Postfix) with ESMTP id AC7F243E09 for ; Fri, 5 Jul 2002 21:44:16 -0700 (PDT) (envelope-from danderse@cs.utah.edu) Received: from famine.cs.utah.edu (famine.cs.utah.edu [155.99.198.114]) by wrath.cs.utah.edu (8.11.6/8.11.6) with ESMTP id g664i7D16705; Fri, 5 Jul 2002 22:44:07 -0600 (MDT) Received: by famine.cs.utah.edu (Postfix, from userid 2146) id 0138A23A77; Fri, 5 Jul 2002 22:44:06 -0600 (MDT) Date: Fri, 5 Jul 2002 22:44:06 -0600 From: "David G . Andersen" To: Ross Wheeler Cc: twig les , Brian Reichert , Kim Okasawa , _@r4k.net, freebsd-security@FreeBSD.ORG Subject: Re: NTP security - (was Any security issues with root's cron job?) Message-ID: <20020705224406.B23004@cs.utah.edu> References: <20020706032916.35363.qmail@web10105.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i In-Reply-To: ; from rossw@albury.net.au on Sat, Jul 06, 2002 at 01:52:13PM +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 Ross Wheeler just mooed: > > Whip over to ebay, buy a cheap second-hand GPS and cable, stick it into > one of your servers and presto - instant "stratum 1" time reference for One thing to note with this approach is that you have to pick your GPS carefully. Hand-helds often have really terrible time output; a friend of mine used his PCMCIA GPS and was getting worse-than-NTP time from it. If you can find it, look for a model that's optimized for time synch. Trimble, UT+, etc. There's a good list of them in the NTP faq at http://www.ntp.org/ > under a hundred bucks. Under your control (I can't see anyone taking over > or DoSing the whole of the GPS network any time soon, do you?) Certainly not to attack one internet site, at least. :) -Dave -- work: dga@lcs.mit.edu me: dga@pobox.com MIT Laboratory for Computer Science http://www.angio.net/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message