RE: [EXTERNAL] Re: I-D Action: draft-templin-duid-ipv6-01.txt

["Templin (US), Fred L" <[e-mail]>]

Bob, I have been offline until just now due to windstorms that knocked out power
and Internet access in the Seattle area over the past couple of days. I will reply to
your question shortly.

Fred

> -----Original Message-----
> From: Bob Hinden [mailto:[e-mail]]
> Sent: Tuesday, January 12, 2021 4:43 PM
> To: Templin (US), Fred L <[e-mail]>
> Cc: Bob Hinden <[e-mail]>; Ole Trøan <[e-mail]>; dhcwg <[e-mail]>; IPv6 List <[e-mail]>;
> Dickson (US), Sean M <[e-mail]>
> Subject: Re: I-D Action: draft-templin-duid-ipv6-01.txt
> 
> Fred,
> 
> > On Jan 12, 2021, at 3:05 PM, Templin (US), Fred L <[e-mail]> wrote:
> >
> > Ole,
> >
> >> -----Original Message-----
> >> From: [e-mail] [mailto:[e-mail]]
> >> Sent: Tuesday, January 12, 2021 1:34 PM
> >> To: Templin (US), Fred L <[e-mail]>
> >> Cc: Bob Hinden <[e-mail]>; dhcwg <[e-mail]>; 6man WG <[e-mail]>; Dickson (US), Sean M
> >> <[e-mail]>
> >> Subject: [EXTERNAL] Re: I-D Action: draft-templin-duid-ipv6-01.txt
> >>
> >> Fred,
> >>
> >> It's unclear to me what the purpose of putting an IPv6 address in the DUID is. Would you mind clarifying that?
> >
> > I will add words to the next draft version.
> 
> How about telling us now.
> 
> Bob
> 
> 
> >
> >> Are you also aware of the following restriction in RFC8415:
> >>   "Clients and servers MUST treat DUIDs as opaque values and MUST only
> >>   compare DUIDs for equality.  Clients and servers SHOULD NOT in any
> >>   other way interpret DUIDs."
> >
> > Yes, but then what is the reason why we currently have 4 DUID types instead
> > of just 1? If the text you quoted above is all there was to it, and end of story,
> > there would never be a need to differentiate DUID-LL from DUID-LLA from
> > DUID-EN from DUID-UUID. So, this suggests there is more to the story than
> > just the short text you quoted above. And, the community has supported the
> > definition of new DUIDs in the past (e.g., DUID-UUID).
> >
> > Thanks - Fred
> >
> >> Best regards,
> >> Ole
> >>
> >>> On 12 Jan 2021, at 19:40, Templin (US), Fred L <[e-mail]> wrote:
> >>>
> >>> Bob, please see my subsequent reply to Eric Vyncke that discusses motivation:
> >>>
> >>> https://mailarchive.ietf.org/arch/msg/ipv6/yOfWHSnt36Hvjr44OERjK0OFvhw/
> >>> https://mailarchive.ietf.org/arch/msg/dhcwg/YZq_aPf1C82ZFT_bTdXOXVXTPW0/
> >>>
> >>> Per your comment, perhaps a new section on "motivation" could be added
> >>> to the draft?
> >>>
> >>> Thanks - Fred
> >>>
> >>>> -----Original Message-----
> >>>> From: Bob Hinden [mailto:[e-mail]]
> >>>> Sent: Tuesday, January 12, 2021 10:22 AM
> >>>> To: Templin (US), Fred L <[e-mail]>
> >>>> Cc: Bob Hinden <[e-mail]>; Mark Smith <[e-mail]>; dhcwg <[e-mail]>; IPv6 List
> >>>> <[e-mail]>; Dickson (US), Sean M <[e-mail]>
> >>>> Subject: Re: I-D Action: draft-templin-duid-ipv6-01.txt
> >>>>
> >>>> Fred,
> >>>>
> >>>> Mark asked:
> >>>>
> >>>> "I don't understand what problem this is trying to solve or see any
> >>>> benefits of it. What is wrong with existing DUIDs?”
> >>>>
> >>>> I have the same question.   I read the draft but have no idea why this is needed.
> >>>>
> >>>> Bob
> >>>>
> >>>>
> >>>>> On Jan 12, 2021, at 8:26 AM, Templin (US), Fred L <[e-mail]> wrote:
> >>>>>
> >>>>> Mark, thanks for the comments. I gather your concern is for the longevity and
> >>>>> immutability of the IPv6 address that would go into the DUID, since DUIDs are
> >>>>> meant to identify the device and not change over time. But, there are IPv6
> >>>>> address generation methods that generate addresses not for the purpose of
> >>>>> assigning them to a physical interface (e.g., Ethernet, WiFi and the like), but
> >>>>> instead to provide a unique node ID for the device that never changes
> >>>>> [RFC7401][draft-ietf-drip-rid]. Also, [RFC7721] mentions several other IPv6
> >>>>> address generation methods that could be considered for use for generating
> >>>>> a unique node ID, and other IPv6 address generation methods intended to
> >>>>> create a unique node ID could be defined in the future.
> >>>>>
> >>>>> So, again, this is not about using an IPv6 address assigned to a physical interface
> >>>>> as a DUID; it is about using an IPv6 address that was intentionally generated to
> >>>>> be a unique identifier for the node and may also be assigned to a virtual interface.
> >>>>>
> >>>>> Thanks - Fred
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: Mark Smith [mailto:[e-mail]]
> >>>>>> Sent: Monday, January 11, 2021 5:32 PM
> >>>>>> To: Templin (US), Fred L <[e-mail]>
> >>>>>> Cc: [e-mail]; dhcwg <[e-mail]>; Dickson (US), Sean M <[e-mail]>
> >>>>>> Subject: Re: FW: I-D Action: draft-templin-duid-ipv6-01.txt
> >>>>>>
> >>>>>>
> >>>>>> Hi Fred,
> >>>>>>
> >>>>>> I don't understand what problem this is trying to solve or see any
> >>>>>> benefits of it. What is wrong with existing DUIDs?
> >>>>>>
> >>>>>> DHCP Unique IDentifiers are, per RFC 8415,
> >>>>>>
> >>>>>> "...  designed to be unique across all DHCP clients and servers, and stable
> >>>>>> for any specific client or server.  That is, the DUID used by a
> >>>>>> client or server SHOULD NOT change over time if at all possible; for
> >>>>>> example, a device's DUID should not change as a result of a change in
> >>>>>> the device's network hardware or changes to virtual interfaces (e.g.,
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> Mrugalski, et al.            Standards Track                   [Page 32]
> >>>>>>
> >>>>>> ________________________________
> >>>>>>
> >>>>>>
> >>>>>> RFC 8415                      DHCP for IPv6                November 2018
> >>>>>>
> >>>>>>
> >>>>>> logical PPP (over Ethernet) interfaces that may come and go in
> >>>>>> Customer Premises Equipment routers).  The client may change its DUID
> >>>>>> as specified in [RFC7844]."
> >>>>>>
> >>>>>> The only IPv6 address that I can think of that might come close to
> >>>>>> meeting those requirements would be an EUI-64 derived Link-Local
> >>>>>> address, and that is assuming that the EUI-64/hardware MAC address
> >>>>>> never changes. MAC address randomisation and the RFC8064
> >>>>>> recommendation for use of RFC7217 for SLAAC means that Link-Local
> >>>>>> addresses may not meet the DUID requirements above either (RFC7217 can
> >>>>>> result in link-specific link-local addresses (specifically the IID
> >>>>>> portion is link specifc), even though the link-local prefix itself is
> >>>>>> constant across all links).
> >>>>>>
> >>>>>> There's also a circular dependency if the DUID is based on a GUA or
> >>>>>> ULA address and DHCPv6 is to then be used for stateful GAU/ULA address
> >>>>>> assignment, unless you mandated that SLAAC and stateful DHCPv6 are
> >>>>>> used in parallel so that SLAAC could be used to derive the DUID that
> >>>>>> is then used to acquire further ULA/GUA addresses via stateful DHCPv6
> >>>>>> IA_NAs and IA_TAs.
> >>>>>>
> >>>>>> "The DUID-V6ADDR may appear in DHCPv6 and/or other protocol control
> >>>>>> messages (such as IPv6 ND) within a service domain when a unique ID
> >>>>>> based on an IPv6 address is required."
> >>>>>>
> >>>>>> In the latter case, why not use IPv6 addresses themselves? Using
> >>>>>> DHCPv6 Unique Identifiers outside of the DHCP protocol would be an
> >>>>>> abuse of a DUID.
> >>>>>>
> >>>>>> Regards,
> >>>>>> Mark.
> >>>>>>
> >>>>>> On Tue, 12 Jan 2021 at 05:47, Templin (US), Fred L
> >>>>>> <[e-mail]> wrote:
> >>>>>>>
> >>>>>>> Hi, more and more IPv6 address generation methods are being specified that
> >>>>>>> intend to generate IPv6 addresses that are highly likely to be unique on either
> >>>>>>> a global scale or unique within a bounded service domain. So much so, that
> >>>>>>> some address generation methods intend for the IPv6 addresses to be usable
> >>>>>>> as node identifiers.
> >>>>>>>
> >>>>>>> Recognizing this, this document proposes a new DHCPv6 DUID type known
> >>>>>>> as "DHCP-V6ADDR" that includes an IPv6 address in the body of the DUID. In
> >>>>>>> this way, IPv6 addresses produced by address generation methods intending
> >>>>>>> to generate a node ID can be used as unique identifiers in DHCPv6 message
> >>>>>>> exchanges. This would introduce a single new DUID type, for which the IANA
> >>>>>>> allocation policy is  "standards action".
> >>>>>>>
> >>>>>>> Alternatively, a separate DUID type could be allocated for each IPv6 address
> >>>>>>> generation method. However, that approach may result in additional IANA
> >>>>>>> allocations and would require implementation updates every time a new
> >>>>>>> address generation method is specified. Hence, a single generic DUID type
> >>>>>>> for all IPv6 generation methods is proposed, but open for discussion.
> >>>>>>>
> >>>>>>> Comments on the list welcome.
> >>>>>>>
> >>>>>>> Fred
> >>>>>>>
> >>>>>>> -----Original Message-----
> >>>>>>> From: I-D-Announce [mailto:[e-mail]] On Behalf Of [e-mail]
> >>>>>>> Sent: Monday, January 11, 2021 10:21 AM
> >>>>>>> To: [e-mail]
> >>>>>>> Subject: I-D Action: draft-templin-duid-ipv6-01.txt
> >>>>>>>
> >>>>>>> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> >>>>>>>
> >>>>>>>
> >>>>>>>      Title           : The IPv6 Address-based DHCPv6 Unique Identifier (DUID-V6ADDR)
> >>>>>>>      Author          : Fred L. Templin
> >>>>>>>      Filename        : draft-templin-duid-ipv6-01.txt
> >>>>>>>      Pages           : 7
> >>>>>>>      Date            : 2021-01-11
> >>>>>>>
> >>>>>>> Abstract:
> >>>>>>> This document defines a new DHCPv6 Unique Identifier (DUID) type
> >>>>>>> called DUID-V6ADDR that contains a single 128 bit IPv6 address.
> >>>>>>> DUID-V6ADDR makes it possible for devices to use suitably-derived
> >>>>>>> unique IPv6 addresses to identify themselves to DHCPv6 servers and/or
> >>>>>>> other network nodes.
> >>>>>>>
> >>>>>>>
> >>>>>>> The IETF datatracker status page for this draft is:
> >>>>>>> https://datatracker.ietf.org/doc/draft-templin-duid-ipv6/
> >>>>>>>
> >>>>>>> There are also htmlized versions available at:
> >>>>>>> https://tools.ietf.org/html/draft-templin-duid-ipv6-01
> >>>>>>> https://datatracker.ietf.org/doc/html/draft-templin-duid-ipv6-01
> >>>>>>>
> >>>>>>> A diff from the previous version is available at:
> >>>>>>> https://www.ietf.org/rfcdiff?url2=draft-templin-duid-ipv6-01
> >>>>>>>
> >>>>>>>
> >>>>>>> Please note that it may take a couple of minutes from the time of submission
> >>>>>>> until the htmlized version and diff are available at tools.ietf.org.
> >>>>>>>
> >>>>>>> Internet-Drafts are also available by anonymous FTP at:
> >>>>>>> ftp://ftp.ietf.org/internet-drafts/
> >>>>>>>
> >>>>>>>
> >>>>>>> _______________________________________________
> >>>>>>> I-D-Announce mailing list
> >>>>>>> [e-mail]
> >>>>>>> https://www.ietf.org/mailman/listinfo/i-d-announce
> >>>>>>> Internet-Draft directories: http://www.ietf.org/shadow.html
> >>>>>>> or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
> >>>>>>>
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