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

Jen Linkova <> Wed, 30 October 2019 00:55 UTC

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From: Jen Linkova <>
Date: Wed, 30 Oct 2019 11:55:11 +1100
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To: Brian E Carpenter <>
Cc: V6 Ops List <>
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Subject: Re: [v6ops] SLAAC renum: Problem Statement & Operational workarounds
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On Tue, Oct 29, 2019 at 12:22 PM Brian E Carpenter
<> wrote:
> > Actually it would be helpful  to define requirements/expectations. I read it as:
> > R1: [MUST HAVE] after the renumbering host is able to open new connections
> How long after? Milliseconds, seconds, or minutes? It makes a lot of difference to the solution.

As soon as the host gets the new address configured.
If the address is assigned to the host interface and applications can
use that address to send packets - then those packets (and return
traffic) should  not be dropped by the network unless it's an explicit
(e.g. security) policy.

> > R2: [NICE TO HAVE] old connections survive the renumbering.
> I believe that when the operators refused to consider SHIM6 ten years ago, they were telling us that they really, truly do not care about that. So this becomes an application layer robustness issue.

Actually I kind of agree. I mean - there are many reasons why a
connection might get stuck/interrupted.
Devices can fail, can be rebooted etc. It would be nice if
applications could take care of this (and some of them do..)
In 'home CPE, DHCP-PD' case we are talking about renumbering happening
as a result of a CPE reboot/failure. So connections would suffer
anyway. Other flash renumbering cases are smth which is not happening
to the network on regular basis - so (IMHO) it's OK for it to be
slightly intrusive.
>     Brian
> _______________________________________________
> v6ops mailing list

SY, Jen Linkova aka Furry