[IPv6]Re: Analysis of Ungleich ULA Registry

[Mark Smith <[e-mail]>]

On Thu, 23 May 2024 at 11:55, David Farmer
<farmer=[e-mail]> wrote:
>
> On Wed, May 22, 2024 at 8:36 PM Kyle Rose <krose=[e-mail]> wrote:
>>
>> On Wed, May 22, 2024 at 9:21 PM David Farmer <farmer=[e-mail]> wrote:
>>>
>>> Many of the names and organizations with the largest number of entries are generic entries. For example, there are 135 name entries with some version of "Admin" or "Administrator" and 52 organization entries with some version of "Private."
>>>
>>> Nevertheless, at least a handful of what seem to be real organizations in the registry purport to use more than 10 ULA prefixes. The limitations of the new known-local ULA list in draft-ietf-6man-rfc6724-update could be problematic for these organizations.
>>>
>>> Also, given the number of names and organizations with multiple entries, there seems to be some evidence for the need for ULA-C prefixes shorter than /48, especially if an organization's justification for shorter prefixes can be evaluated.
>>
>>
>> We are not the protocol police.
>
>
> Indeed, we are not. Nevertheless, if the data is to be believed, people are, in fact, using multiple /48s. I'm simply saying that is a fact, and it counters the argument that "no one needs more than a /48," at least in my opinion.
>

I think you can only conclude that if you believe that most people are
generating ULA /48s correctly. I've seen enough examples that they
aren't such that I don't assume anymore that individual people are
following RFC 4193 correctly unless I see some signs or evidence that
they are.

The two main reasons to need a larger prefix that a current one are:

- you don't have enough address space / subnets

- you need to aggregate at points within your network to scale either
your routing protocol or your router's FIBs.

With a single /48 ULA providing 65 536 /64s, with many organisations
not having many 10s of 1000s of links to number within their network,
with BGP easily scaling to 65 536 routes without aggregation, with a
network using BGP for large scale routing likely to have routers with
large FIB capacities, with many organisations not having 10s of 1000s
of hosts to give individual /64s if that was the deployment choice,
and with other scaling techniques like using an EVPN with ND/ARP proxy
(RFC 9161) to put many hosts inside a single /64 subnet, I don't think
shorter than /48 ULA is actually a common requirement at all.

Regards,
Mark.


> You and others are completely entitled to your counter-opinion.
>
> Thanks
>
> --
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