IETF Logo Mail Archive

[Ntp] Antw: [EXT] Re: [tsvwg] [Tsv‑art] Tsvart early review of draft‑ietf‑ntp‑alternative‑port‑02

Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de> Wed, 08 December 2021 07:37 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 [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 872243A0B4F; Tue, 7 Dec 2021 23:37:43 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id H-HIHMialgjL; Tue, 7 Dec 2021 23:37:41 -0800 (PST)
Received: from mx2.uni-regensburg.de (mx2.uni-regensburg.de [IPv6:2001:638:a05:137:165:0:3:bdf8]) (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 4573B3A0B4D; Tue, 7 Dec 2021 23:37:39 -0800 (PST)
Received: from mx2.uni-regensburg.de (localhost [127.0.0.1]) by localhost (Postfix) with SMTP id 035D56000053; Wed, 8 Dec 2021 08:37:35 +0100 (CET)
Received: from gwsmtp.uni-regensburg.de (gwsmtp1.uni-regensburg.de [132.199.5.51]) by mx2.uni-regensburg.de (Postfix) with ESMTP id DE0BB6000052; Wed, 8 Dec 2021 08:37:32 +0100 (CET)
Received: from uni-regensburg-smtp1-MTA by gwsmtp.uni-regensburg.de with Novell_GroupWise; Wed, 08 Dec 2021 08:37:32 +0100
Message-Id: <61B060BA020000A1000461F2@gwsmtp.uni-regensburg.de>
X-Mailer: Novell GroupWise Internet Agent 18.3.1
Date: Wed, 08 Dec 2021 08:37:30 +0100
From: Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
To: mayer@pdmconsulting.net, mlichvar@redhat.com
Cc: magnus.westerlund@ericsson.com, Steven Sommars <stevesommarsntp@gmail.com>, iana-port-experts@icann.org, draft-ietf-ntp-alternative-port.all@ietf.org, "ntp@ietf.org" <ntp@ietf.org>, tsv-art@ietf.org, tsvwg@ietf.org, stenn@nwtime.org, heard@pobox.com, halmurray@sonic.net, touch@strayalpha.com
References: <20211204231206.A534228C17A@107-137-68-211.lightspeed.sntcca.sbcglobal.net> <A803AF18-2BBD-4A54-9802-3EF693066E6C@strayalpha.com> <CAD4huA7RhF3xZJkdghz4yx3qk8uBjkfJv7Y_hDCvX1a=wATBkg@mail.gmail.com> <CACL_3VENkyebRf25W6EpW0yZY6ELYS41A4D_i+RnQE1M21P2hg@mail.gmail.com> <Ya3fLJCHUsm1wE28@localhost> <90723c26-0352-a4d1-f765-eb26b1522954@pdmconsulting.net> <Ya8bcmEO04g1TCzB@localhost>
In-Reply-To: <Ya8bcmEO04g1TCzB@localhost>
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/ZHn3MNZVjtPpwiFXzRkV0Lqczeg>
X-Mailman-Approved-At: Wed, 08 Dec 2021 07:08:57 -0800
Subject: [Ntp] Antw: [EXT] Re: [tsvwg] [Tsv‑art] Tsvart early review of draft‑ietf‑ntp‑alternative‑port‑02
X-BeenThere: ntp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Network Time Protocol <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: Wed, 08 Dec 2021 07:37:44 -0000

>>> Miroslav Lichvar <mlichvar@redhat.com> schrieb am 07.12.2021 um 09:29 in
Nachricht <Ya8bcmEO04g1TCzB@localhost>:
...
> The problematic middleboxes don't block other ports. They specifically
> block or rate limit packets on the port 123 as a mitigation for the
> amplification attacks. If a non‑amplifying subset of NTP moves to
> another port, they will have no reason to block it.

But when noticing that NTP uses a different port, they could also notice how
to fix their servers (regarding mode 6 and mode 7). Autokey shouldn't be a
common problem I guess.

...

Regards,
Ulrich

v2.23.0 | Report a Bug | By Email