[Ntp] Antw: Re: Antw: Re: Antw: Re: Calls for Adoption -- NTP Extension Field drafts -- Four separate drafts

"Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de> Mon, 02 September 2019 10:39 UTC

Return-Path: <Ulrich.Windl@rz.uni-regensburg.de>
X-Original-To: ntp@ietfa.amsl.com
Delivered-To: ntp@ietfa.amsl.com
Received: from localhost (localhost []) by ietfa.amsl.com (Postfix) with ESMTP id E12EA120089 for <ntp@ietfa.amsl.com>; Mon, 2 Sep 2019 03:39:02 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.2
X-Spam-Status: No, score=-4.2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([]) by localhost (ietfa.amsl.com []) (amavisd-new, port 10024) with ESMTP id VIrp37B5-vga for <ntp@ietfa.amsl.com>; Mon, 2 Sep 2019 03:39:01 -0700 (PDT)
Received: from mx3.uni-regensburg.de (mx3.uni-regensburg.de []) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id D1BF112006B for <ntp@ietf.org>; Mon, 2 Sep 2019 03:39:00 -0700 (PDT)
Received: from mx3.uni-regensburg.de (localhost []) by localhost (Postfix) with SMTP id 60BC56000050 for <ntp@ietf.org>; Mon, 2 Sep 2019 12:38:58 +0200 (CEST)
Received: from gwsmtp.uni-regensburg.de (gwsmtp1.uni-regensburg.de []) by mx3.uni-regensburg.de (Postfix) with ESMTP id 478BF600004D for <ntp@ietf.org>; Mon, 2 Sep 2019 12:38:58 +0200 (CEST)
Received: from uni-regensburg-smtp1-MTA by gwsmtp.uni-regensburg.de with Novell_GroupWise; Mon, 02 Sep 2019 12:38:58 +0200
Message-Id: <5D6CF140020000A100033441@gwsmtp.uni-regensburg.de>
X-Mailer: Novell GroupWise Internet Agent 18.1.1
Date: Mon, 02 Sep 2019 12:38:56 +0200
From: "Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de>
To: "ntp@ietf.org" <ntp@ietf.org>,<mlichvar@redhat.com>
References: <Ulrich.Windl@rz.uni-regensburg.de> <5D6CB84E020000A100033405@gwsmtp.uni-regensburg.de> <20190902093750.DA05940605C@ip-64-139-1-69.sjc.megapath.net> <20190902095854.GC15024@localhost> <EC0267640200002C6A6A8CFC@gwsmtp.uni-regensburg.de> <A7C4D27502000083822C0D04@gwsmtp.uni-regensburg.de> <D5F28766020000316A6A8CFC@gwsmtp.uni-regensburg.de> <2E18D20E0200009A822C0D04@gwsmtp.uni-regensburg.de> <4B834D170200006586EDC2A6@gwsmtp.uni-regensburg.de> <831B91BE020000B87ED719BE@gwsmtp.uni-regensburg.de> <5D6CB84E020000A100033405@gwsmtp.uni-regensburg.de> <6A31A7C90200006043047E14@gwsmtp.uni-regensburg.de> <87F2C84C0200007A6A6A8CFC@gwsmtp.uni-regensburg.de>
In-Reply-To: <87F2C84C0200007A6A6A8CFC@gwsmtp.uni-regensburg.de>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Content-Disposition: inline
Archived-At: <https://mailarchive.ietf.org/arch/msg/ntp/TKGJuuHoXZHcXkSYTF1N8AsUOqg>
Subject: [Ntp] Antw: Re: Antw: Re: Antw: Re: Calls for Adoption -- NTP Extension Field drafts -- Four separate drafts
X-BeenThere: ntp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <ntp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ntp>, <mailto:ntp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ntp/>
List-Post: <mailto:ntp@ietf.org>
List-Help: <mailto:ntp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ntp>, <mailto:ntp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 02 Sep 2019 10:39:03 -0000

>>> Miroslav Lichvar <mlichvar@redhat.com> schrieb am 02.09.2019 um 11:58 in
Nachricht <20190902095854.GC15024@localhost>:
> On Mon, Sep 02, 2019 at 02:37:50AM ‑0700, Hal Murray wrote:
>> Ulrich.Windl@rz.uni‑regensburg.de said:
>> > But remember that a "node" is NOT "an IP address". With multi‑homed hosts

> you
>> > can have interesting synchronization loops... ;‑) 
>> Is there a problem with using an IPv6 address to identify a system?  (if
> are multi‑homed, just pick one)

So in principle that ID could change at a server restart?

> If the system has multiple addresses, its clients may not know all of
> them and may fail to detect loops. Addresses are no good.

Yes, especially if virtual IP addresses come and go.

> We need each server (or rather the clock) to have an ID and extend the
> protocol to exchange this ID so clients (that operate also as servers)
> can reliably detect 1‑degree loops. The suggested‑refid EF basically
> does that.


> ‑‑ 
> Miroslav Lichvar
> _______________________________________________
> ntp mailing list
> ntp@ietf.org 
> https://www.ietf.org/mailman/listinfo/ntp