Re: [v6ops] Comments on ULA draft

Brian E Carpenter <> Fri, 21 July 2017 04:52 UTC

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To: "Liubing (Leo)" <>, Lorenzo Colitti <>
Cc: "" <>, " WG" <>
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From: Brian E Carpenter <>
Organization: University of Auckland
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Date: Fri, 21 Jul 2017 16:52:46 +1200
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Subject: Re: [v6ops] Comments on ULA draft
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On 21/07/2017 03:31, Liubing (Leo) wrote:
> Btw, the admins could randomly generated a single one 48/ ULA prefix, and announce it internally, there are still 16bit for sub-organization. So, this could be considered as kind of aggregation?.
> Yes, but only for a small network.
> [Bing2] I don’t quite understand why only for small networks? Is it because the 16bit is not enough for a large organization to divide sub-networks?

With 16 routing bits to play with, the admin has basically the equivalent of
an IPv6 Class A (which contains 2**16 /24s). So yes, campus or regional
based aggregation is entirely possible: to exactly the same extent as with
a GUA /48, of course. In fact, in a network running both a GUA and a ULA
prefix, I'd expect the same aggregation plan to be used for both.