[Ntp] NTP errors

Hal Murray <hmurray@megapathdsl.net> Mon, 09 September 2019 20:29 UTC

Return-Path: <hmurray@megapathdsl.net>
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 92D261200B8 for <ntp@ietfa.amsl.com>; Mon, 9 Sep 2019 13:29:02 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 1.035
X-Spam-Level: *
X-Spam-Status: No, score=1.035 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HELO_DYNAMIC_IPADDR=1.951, RDNS_DYNAMIC=0.982, SPF_HELO_NONE=0.001, SPF_NONE=0.001] autolearn=no 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 NO0mNmmah2gT for <ntp@ietfa.amsl.com>; Mon, 9 Sep 2019 13:28:58 -0700 (PDT)
Received: from ip-64-139-1-69.sjc.megapath.net (ip-64-139-1-69.sjc.megapath.net [64.139.1.69]) by ietfa.amsl.com (Postfix) with ESMTP id 4D845120048 for <ntp@ietf.org>; Mon, 9 Sep 2019 13:28:58 -0700 (PDT)
Received: from shuksan (localhost [127.0.0.1]) by ip-64-139-1-69.sjc.megapath.net (Postfix) with ESMTP id DD72140605C; Mon, 9 Sep 2019 13:28:57 -0700 (PDT)
X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.3
To: "ntp@ietf.org" <ntp@ietf.org>
cc: Hal Murray <hmurray@megapathdsl.net>
From: Hal Murray <hmurray@megapathdsl.net>
In-Reply-To: Message from Daniel Franke <dfoxfranke@gmail.com> of "Mon, 09 Sep 2019 12:18:01 EDT." <CAJm83bC81BWxGPmGbaTgxU6vmKtWF_-j5oMohyU9M5YX9HqbYQ@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Mon, 09 Sep 2019 13:28:57 -0700
Message-Id: <20190909202857.DD72140605C@ip-64-139-1-69.sjc.megapath.net>
Archived-At: <https://mailarchive.ietf.org/arch/msg/ntp/J9nHdTUDIdKoychmfcHVpg8L8XA>
Subject: [Ntp] NTP errors
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, 09 Sep 2019 20:29:03 -0000

dfoxfranke@gmail.com said:
> But it's really silly for a v4 server to attempt to reply to a v5 request
> with anything but an error.

Agreed, but it's more complicated than that.  Error replies can be forged.

I think error handling needs more thought.

Another tangle in this area is rate-limiting.  With NAT, you can get 
legitimate traffic from many hosts funneled through one IPv4 address.

Are there any error-cases where the client should do something because the 
amount of trouble from not doing anything is higher than the amount of trouble 
from processing a forged packet?

"Amount of trouble" probably depends on whether you are the server or client.  
How should we think about that?



-- 
These are my opinions.  I hate spam.