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

Ole Troan <otroan@employees.org> Thu, 14 November 2019 16:43 UTC

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From: Ole Troan <otroan@employees.org>
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Date: Fri, 15 Nov 2019 00:42:59 +0800
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Subject: Re: [v6ops] What problem are we trying to solve? (Re: 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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> Your lifetimes should not be so long. Graceful renumbering means advertising two prefixes, one deprecated. You keep the route for the deprecated prefix up until the valid lifetime expires. Then you eliminate it. The number of routes should not grow over time. 

Actually that's not quite what graceful renumbering means, since it wouldn't be so graceful if you did it that way.
Basically it's two valid prefixes overlapping. Where you ensure no new sessions use it by letting preferred lifetime go to zero, and ensure that the deprecated timers doesn't expire before after the longest expected session lifetime has passed.

Cheers,
Ole