IPv6: IS-IS or OSPFv3

Sun Dec 28 20:41:46 UTC 2008

>>> In practice, we realized that enabling IS-ISv6 on interfaces
>>> already running IS-ISv4 was problematic without MT pre-
>>> configured.
>>> Those links surely lost IS-IS adjacency which threatened stability
>>> of the network.
>> Yup, that is the rub: if rolling out your v6 routing impacts your v4
>> routing you are not "winning".
>
>this is not very deep.

Is it untrue?

>
>mark did point out how to avoid it, pointing out why mt was very useful
>as opposed to just another bell and whistle.  during a transition, in
>fact, topologies are not congruent due to inability to have a flag
>millisecond, a very very useful observation.

Indeed, and not creating the problem is good thing.  I don't think we are
disagreeing on anything here ... 

Although I don't believe anyone has mentioned "multi-topology" +
"transition" just yet, the goal being that when you go from ST to MT
(assuming you aren't already there, that is) you don't impact ongoing
operations / neighborships.

/TJ