[Anima] Warren Kumari's No Objection on draft-ietf-anima-prefix-management-06: (with COMMENT)

[Warren Kumari <[e-mail]>]

Warren Kumari has entered the following ballot position for
draft-ietf-anima-prefix-management-06: No Objection

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COMMENT:
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Thank you.

I did have some comments / questions.
I'd also like to draw both the authors, and AD's attention to Fred Bakers
excellent thoughts in his OpsDir review -
https://datatracker.ietf.org/doc/review-ietf-anima-prefix-management-06-opsdir-lc-baker-2017-10-23/

Firstly, a global concern:
This technique (and I suspect many automated prefix allocations where a device
uses space, and then requests more) is likely (I think) to result in
fragmentation of the address space - this will lead to more routing entries in
the IGP, which may be an issue for smaller routers or "L3 switches". I think
that it would be useful to note this.

I also wanted to make sure that the author of this document were aware of the
CASM BoF from IETF98 - I've just checked, and see that at least Qiong Sun was
associated with the work (draft-xie-ps-centralized-address-management).

I had a question -- I don't really understand what: [Page 9] "A gateway router
in a hierarchical network topology normally provides prefixes for routers
within its subnet, ..." is trying to say. I've seen many "hierarchical network
topologies" and don't believe this to be true, nor do I really understand what
"its subnet" means. In some cases a router will announce an aggregate for
customers behind it, but I don't really view that as a general case. I'm
guessing I'm just not understanding - can you please educate me?