Re: SLAAC vs DHCPv6 (II)

Michael Richardson <mcr+ietf@sandelman.ca> Thu, 30 January 2020 17:49 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Fernando Gont <fgont@si6networks.com>
cc: Lorenzo Colitti <lorenzo@google.com>, "Pascal Thubert (pthubert)" <pthubert@cisco.com>, 6man WG <ipv6@ietf.org>, Suresh Krishnan <Suresh@kaloom.com>, JORDI PALET MARTINEZ <jordi.palet=40consulintel.es@dmarc.ietf.org>
Subject: Re: SLAAC vs DHCPv6 (II)
In-reply-to: <2ea73f99-9fed-4aa0-6f70-884896cc626a@si6networks.com>
References: <03C832CE-7282-4320-BF1B-4CB7167FE6BE@employees.org> <80207E17-AE8E-4D19-B516-D2E6AB70721E@employees.org> <8D5610EA-49D3-483E-BB7A-67D67BC89346@jisc.ac.uk> <DE7B0688-230F-4A5C-8E24-9EAED9FD9FEB@puck.nether.net> <AFEBAD7D-DF24-4924-8B9A-60DF22BA1953@consulintel.es> <c42affce-fbd3-23ec-c9ff-4f05cdf38630@si6networks.com> <41173152-A8E8-4241-9DE7-376AA7AFB813@consulintel.es> <c4166907-b6c9-a4ef-fd59-cf539bbe0405@si6networks.com> <43D76C96-C16B-4BEB-B9B8-C68D53BCE63F@fugue.com> <fb5b8377-892d-2777-ef9b-4f9ddefa6c93@si6networks.com> <CAKD1Yr034_tu7ZoJ1FCfDYhNSN6igm-ZQyR4u3U+UDMr=huGOw@mail.gmail.com> <1af0b06d-f9d7-5ea1-27f3-b417eb9148fa@si6networks.com> <7606A049-318D-4526-917D-F2A801BF7050@cisco.com> <CAKD1Yr1d9kORFdoOJr22J_UDJ9hLPr6AQLyWuh7=bAQKa+aXGw@mail.gmail.com> <MN2PR11MB356588FC3E8A6410B725D159D80A0@MN2PR11MB3565.namprd11.prod.outlook.com> <CAKD1Yr35meRGh_POo_2jrHA_oazO1xUOG5G_rx43xNLFYHQsMQ@mail.gmail.com> <2ea73f99-9fed-4aa0-6f70-884896cc626a@si6networks.com>
Comments: In-reply-to Fernando Gont <fgont@si6networks.com> message dated "Tue, 28 Jan 2020 13:44:28 -0300."
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Date: Thu, 30 Jan 2020 09:14:17 -0500
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Fernando Gont <fgont@si6networks.com> wrote:
    >> But it does violate the recommendation if you use it to enforce how
    >> many addresses the host can use. The text is:
    >> 
    >> Due to the drawbacks imposed by requiring explicit requests for
    >> address space (seeSection 4
    >> <https://tools.ietf.org/html/rfc7934#section-4>), it is RECOMMENDED
    >> that the network give the host the ability to use new addresses
    >> without requiring explicit requests.  This can be achieved either by
    >> allowing the host to form new addresses autonomously (e.g., via SLAAC)
    >> or by providing the host with a dedicated /64 prefix.  The prefix MAY
    >> be provided using DHCPv6 PD, SLAAC with per-device VLANs, or any other
    >> means.
    >> 
    >> 
    >> If the network is able to deny a registration, then it's not a
    >> registration, it's a request.

    > The network always wins. Folks could run SAVI, and enforce one addrees
    > per node, even with SLAAC. Yes, you're address wouldn't be rejected
    > .. it just wouldn't work. The outcome is the same.

It would be impossible to debug, so the user turns off IPv6, and we all lose.


-- 
Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works
 -= IPv6 IoT consulting =-