[Ntp] Antw: [EXT] Re: Last Call: <draft-ietf-ntp-using-nts-for-ntp-22.txt> (Network Time Security for the Network Time Protocol) to Proposed Standard

"Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de> Wed, 26 February 2020 08:39 UTC

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Date: Wed, 26 Feb 2020 09:39:15 +0100
From: "Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de>
To: "Steven Sommars" <stevesommarsntp@gmail.com>,<last-call@ietf.org>
Cc: <draft-ietf-ntp-using-nts-for-ntp@ietf.org>, <ietf-announce@ietf.org>,"ntp@ietf.org" <ntp@ietf.org>, "ntp-chairs@ietf.org" <ntp-chairs@ietf.org>, <odonoghue@isoc.org>, <suresh@kaloom.com>
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Subject: [Ntp] Antw: [EXT] Re: Last Call: <draft-ietf-ntp-using-nts-for-ntp-22.txt> (Network Time Security for the Network Time Protocol) to Proposed Standard
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>>> Steven Sommars <stevesommarsntp@gmail.com> schrieb am 24.02.2020 um 15:51 in
> There is substantial size-based blocking of UDP port 123 IPv4 packets by
> ISPs/IXPs.  From one NTP monitoring point I saw about one third of the NTP
> destinations unreachable (dropped en route) for  212-460 byte port 123
> UDP.  Another monitoring point experienced blocking for all NTP
> destinations when the size was greater than 428 bytes.  Size-based NTP
> blocking is not a secret; it was discussed on the NANOG mailing list in
> 2014 (see for example
> https://mailman.nanog.org/pipermail/nanog/2014-February/064634.html ).
> NTP requests can be dropped, so  section 9.3 of draft 22 does not address
> the problem.   While NTS will not be a DDoS amplification source, it will
> be affected by existing DDoS countermeasures.
> How will NTS work in today's UDP-unfriendly Internet?

Maybe a candidate for the best practices: "How to block unwanted NTP packets correctly?", "Should NTP packets be blocked?". Here I can't use any external NTP server, BTW. I feel safe ;-)

> On Fri, Feb 14, 2020 at 8:47 AM The IESG <iesg-secretary@ietf.org> wrote:
>> The IESG has received a request from the Network Time Protocol WG (ntp) to
>> consider the following document: - 'Network Time Security for the Network
>> Time Protocol'
>>   <draft-ietf-ntp-using-nts-for-ntp-22.txt> as Proposed Standard
>> The IESG plans to make a decision in the next few weeks, and solicits final
>> comments on this action. Please send substantive comments to the
>> last-call@ietf.org mailing lists by 2020-02-28. Exceptionally, comments
>> may
>> be sent to iesg@ietf.org instead. In either case, please retain the
>> beginning
>> of the Subject line to allow automated sorting.
>> Abstract
>>    This memo specifies Network Time Security (NTS), a mechanism for
>>    using Transport Layer Security (TLS) and Authenticated Encryption
>>    with Associated Data (AEAD) to provide cryptographic security for the
>>    client-server mode of the Network Time Protocol (NTP).
>>    NTS is structured as a suite of two loosely coupled sub-protocols.
>>    The first (NTS-KE) handles initial authentication and key
>>    establishment over TLS.  The second handles encryption and
>>    authentication during NTP time synchronization via extension fields
>>    in the NTP packets, and holds all required state only on the client
>>    via opaque cookies.
>> The file can be obtained via
>> https://datatracker.ietf.org/doc/draft-ietf-ntp-using-nts-for-ntp/ 
>> IESG discussion can be tracked via
>> https://datatracker.ietf.org/doc/draft-ietf-ntp-using-nts-for-ntp/ballot/ 
>> No IPR declarations have been submitted directly on this I-D.
>> The document contains these normative downward references.
>> See RFC 3967 for additional information:
>>     rfc5297: Synthetic Initialization Vector (SIV) Authenticated
>> Encryption Using the Advanced Encryption Standard (AES) (Informational -
>> IETF stream)
>> _______________________________________________
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