Re: [v6ops] Flash renumbering

[Richard Patterson <[e-mail]>]

That is actually still just option a), and could result in packets being
sourced from the wrong prefix in a multi-homed, multi-prefixed environment.

On Mon, 21 Sep 2020 at 12:05, Vasilenko Eduard <[e-mail]>
wrote:

> Hi Richard,
>
> I have sent in reply to Fernando details: RFC 7084 has chosen different
> option:
> d) continue sending old PIO, but inform hosts that this router is not
> default anymore
>
> IMHO: it is right!
>
>
>
> RFC 7084 Basic Requirements for IPv6 Customer Edge Routers
>
> L-3:   An IPv6 CE router MUST advertise itself as a router for the
> delegated prefix(es) (and ULA prefix if configured to provide ULA
> addressing) using the "Route Information Option" specified in Section 2.3
> of [RFC4191].
>
> *This advertisement is independent of having or not having IPv6
> connectivity on the WAN interface*.
>
> L-4:   An IPv6 CE router MUST NOT advertise itself as a default router
> with a Router Lifetime [RFC4861] greater than zero if it has no prefixes
> configured or delegated to it.
>
> Eduard
>
> *From:* Richard Patterson [mailto:[e-mail]]
> *Sent:* 18 сентября 2020 г. 23:31
> *To:* Vasilenko Eduard <[e-mail]>
> *Cc:* [e-mail]
> *Subject:* Re: [v6ops] Flash renumbering
>
>
>
> On Fri, 18 Sep 2020 at 20:47, Vasilenko Eduard <
> [e-mail]> wrote:
>
> From standard point of view
>
> local traffic should not stop after CPE would lose uplink,
>
> Because internal CPE switch should still switch traffic
>
> After internal CPE router would stop promoting itself a router for this
> link
>
>
>
>
>
> In this scenario, when the WAN interface (native Ethernet or PPP) goes
> down, would you expect the CPE router to:
>
> a) continue sending RAs with the old prefix PIO as if nothing has happened.
>
> b) send an RA with PIO prefered lifetime of 0
>
> c) simply stop sending RAs with the PIO
>
>
>
>
>
> a. messes up multihoming, and is a bit disingenuous of the CPE to continue
> advertising
>
> b. Helps deprecate the stale GUA prefix but means we lose local IPv6
> connectivity
>
> c. Prevents new devices from attaching and getting local IPv6 connectivity
>
>
>
> ULA would help retain local IPv6 connectivity behind CPEs that implement b
> & c.
>
> I'm kinda wishing we included a recommendation for the use of ULA in
> draft-ietf-v6ops-cpe-slaac-renum.  But I imagine that would be rather
> contentious
>