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

Fernando Gont <> Thu, 31 October 2019 19:44 UTC

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To: Philip Homburg <>,
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Subject: Re: [v6ops] SLAAC renum: Problem Statement & Operational workarounds
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On 27/10/19 12:05, Philip Homburg wrote:
>> Indeed, this would also
>> not actually solve the problem.   At present, the ISPs are doing
>> something that is out of spec and causes problems.   If we fix this
>> by accommodating what they do, does that help, or does it just
>> encourage them to continue doing it?
> At the moment, ISPs are doing something that sort of works in IPv4 because
> of NAT. It causes significant issues in IPv6.

Note that this is *one* of the network scenarios that may lead to this
problematic scenario.

> Of course, can we can tell ISPs that they are doing it wrong and that they
> should not deploy IPv6 until they have fixed their networks.
> I would like to have IPv6 now. And if that requires some tweaks to deal with
> broken behavior then so be it.

Indeed. Besides, the patch increases robustness overall.

>> If you Really Really want to be able to have the routers send out
>> RAs that deprecate the default route, and, as Mark is saying here,
>> to upgrade millions or perhaps billions of hosts, why not ask for
>> something thats a real improvement?
> Because bundling features is a good way to ensure that nothing gets done.


Fernando Gont
SI6 Networks
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