Re: [Isis-wg] [Bier] WGLC: draft-ietf-bier-isis-extensions-04

[Tony Przygienda <[e-mail]>]

On Sat, Jul 22, 2017 at 8:03 AM, Les Ginsberg (ginsberg) <[e-mail]
> wrote:

> Tony/Toerless –
>
>
>
> There is an explicit statement as to scope:
>
>
>
> <snip>
>
> Section 4.2
>
> …
>
>    o  BIER sub-TLVs MUST NOT be included when a prefix reachability
>
>       advertisement is leaked between levels.
>
> <end snip>
>

sigh, missed that on fly-over.


>
>
> Tony seems to have forgotten that we had a discussion about how BIER might
> be supported across areas and the conclusion was we did not know how to do
> that yet.
>
> (Sorry Tony)
>

I forgot about that specifically since we had multiple discussions, you,
Peter, others and different conclusions have been reached in time per
protocol. You're here to keep my distracted self honest ...

OK< with that I think ISIS is a no-action-necessary.



>
>
> Note this is “consistent” with https://www.ietf.org/id/draft-
> ietf-bier-ospf-bier-extensions-07.txt Section 2.5 - which limits the
> flooding scope of BIER information to a single area unless it can be
> validated that the best path to the prefix with BIER info can be validated
> to be to a router which itself advertised the BIER info.
>

ah, ok, I see that that we're area-scope now as well. I know we had an
agreement before that it would be AS scope or something so that changed and
is consistent ...

IMO no action on OSPF necessary either, Toerless ... Sorry for my imperfect
memories when we talked ....


> This is not something IS-IS can do since a single IS-IS instance only
> supports one area and therefore does not have the Level-1 advertisements of
> the originating router when that router is in another area.
>
>
>

Well, we could say "loopbacks must be leaked ..." and so on but this is
cleaner. We limit ourselves and solve the problem in the general ISIS
framework if it comes up ...

thanks Les

--- tony