Re: [Anima] [homenet] ANIMA scope + homenet interaction + charter v15

[Sheng Jiang <[e-mail]>]

Hi, Ted,

I now understand your point. Your arguments do make sense. The current general mechanism are too general to work for the use case of hierarchical prefix delegation. But if we add hierarchical topology and no bypass requests as constraint conditions, we may be able to make hierarchical prefix delegation work.

Best regards,

Sheng
________________________________________
From: Ted Lemon [[e-mail]]
Sent: 31 October 2014 22:34
To: Sheng Jiang
Cc: Benoit Claise; [e-mail]; Markus Stenberg; [e-mail]
Subject: Re: [Anima] [homenet] ANIMA scope + homenet interaction + charter v15

On Oct 31, 2014, at 8:54 AM, Sheng Jiang <[e-mail]> wrote:
> Are you talking about assigning prefix for homenet? I thought we were talking about auto prefix management in a large network, which is ANIMA use case.

In either case, it's important to make the distinction between prefix assignment and prefix delegation.   In an autonomous network, I don't think it's practical to do hierarchical prefix delegation.   That has the unfortunate consequence that there can't be any routing aggregation.   The delegating router can of course _try_ to keep the topology clean, but routing has to work even if it fails.

That being the case, every delegation _request_ should be for a /64, because every delegation request should be a request for a /64 to configure on an interface of a router.   Whether or not aggregation occurs is up to whichever device is the delegating router.   Having a distributed delegation framework is probably a good idea, but a hierarchical distribution won't work, so the idea that a router could request prefixes to be delegated and then re-delegate some of those prefixes is, IMHO, not going to work.