Re: [v6ops] SLAAC renum: Problem Statement & Operational workarounds

[Fernando Gont <[e-mail]>]

On 27/10/19 10:54, Ted Lemon wrote:
> On Oct 27, 2019, at 9:41 AM, Philip Homburg <[e-mail]
> <mailto:[e-mail]>> wrote:
>> The little bit missing is that the CPE should write prefixes
>> advertised using
>> SLAAC to persistent storage which allows the CPE to invalidate stale
>> prefixes
>> after a reboot.
> 
> Actually I do not believe this is correct behavior.   Let us assume
> prefix delegation.   If we have prefix delegation, then when the CPE
> comes back from a power cycle, it should reconfirm the prefix it had
> previously; the assumption is that that prefix is still valid.  This can
> be handled in infrastructure—the ISP edge router should know whether the
> prefix is still valid, because if it is it should be advertising a route
> for it.   If it is not still valid, then the CPE router should attempt
> to renew it, which would go to the DHCP server (possibly both messages
> would).

That assues the CPE has stored the previously-leased prefix on stable
storage -- which does not need to be the case. Hence the related text in
our I-D.

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: [e-mail]
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