Re: [v6ops] A broken promise - "You said PD Prefix Valid Lifetime is going to be X" (Re: SLAAC renum: Problem Statement & Operational workarounds)

Fernando Gont <fgont@si6networks.com> Mon, 11 November 2019 23:38 UTC

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To: Mark Smith <markzzzsmith@gmail.com>, Ted Lemon <mellon@fugue.com>
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From: Fernando Gont <fgont@si6networks.com>
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Subject: Re: [v6ops] A broken promise - "You said PD Prefix Valid Lifetime is going to be X" (Re: SLAAC renum: Problem Statement & Operational workarounds)
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On 11/11/19 16:47, Mark Smith wrote:
> 
> 
> On Tue, 12 Nov 2019, 04:11 Ted Lemon, <mellon@fugue.com
> <mailto:mellon@fugue.com>> wrote:
> 
>     Nobody is expecting you to never renumber.   Well, at least I am not.
> 
> 
> I'm not either.
> 
> IPv6's Preferred and Valid lifetime mechanisms are for planned renumbering.
> 
> 
>     What I am talking about here is deliberate, opportunistic
>     renumbering. If your topology changes and you have to renumber, so
>     be it. 
> 
> 
> Unplanned "flash" renumbering due to a topology change implies an
> unplanned "flash" topology change. That's going to be a rare event, and
> ideally shouldn't ever occur, because I think it is a sign that some
> other planning hasn't been occurring.
> 
> 
> I don't really understand what is so hard about all this. 
> 
> You either provide prefix stability using a client's DUID, or you can
> use RADIUS.

As noted elsewhere, we have an RFC for DUID radnomization ("dhcp
anynimity profile", iirc). Besides, it's also understandable the
possible expectation of a user to get a new prefix upon CPE reboot (due
to privacy considerations).


-- 
Fernando Gont
SI6 Networks
e-mail: fgont@si6networks.com
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