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

Ted Lemon <mellon@fugue.com> Fri, 31 October 2014 14:34 UTC

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From: Ted Lemon <mellon@fugue.com>
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To: Sheng Jiang <jiangsheng@huawei.com>
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Subject: Re: [Anima] [homenet] ANIMA scope + homenet interaction + charter v15
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On Oct 31, 2014, at 8:54 AM, Sheng Jiang <jiangsheng@huawei.com> 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.