Re: Happy St Nicholas Day: Re-Launching the IPv6 ULA registry

[Fernando Gont <[e-mail]>]

Hello, Brian,

On 7/12/20 17:20, Brian E Carpenter wrote:
>> On 6/12/20 21:42, Lorenzo Colitti wrote:
>>> Nico,
>>>
>>> This seems a bit misguided for several reasons.
>>>
>>> First, registries are supposed to be authoritative databases, but the
>>> RFC specifies that ULA addresses are generated pseudo-randomly.
>>
>> Strictly speaking, there exist registries that are not authoritative --
>> e.g., think of the registered ports in the port number registry.
> 
> That's not a useful analogy. Those ports need to be registered because
> they are potentially used across the open Internet.

I'm not sure that's the case (i.e., that all registerd ports are used in 
the open Internet).  That said, I was simply pointing out that such 
registry does have "conflicts" -- i.e., same port used by multiple 
protocols/apps.


> ULAs are by
> definition not used across the open Internet. Therefore, they don't
> need a registry.

Agreed on this one.



>> That said, I'm not sure:
>>
>> 1) Whether folks would be compelled to register their blocks.
> 
> I'm sure: no.


I, for one, wouldn't :-)



>> That aside, in a way the whole point of randomizing the ULA prefix is
>> that results statistically unique. So, provided folks do follow the
>> advice in the ULA spec (I for one have *not :-) in a number of
>> occasions), there shouldn't be much of a need to actually register ULA
>> prefixes... (if the prefixes are unique... who cares who uses what?)
> 
> Sorry, but I don't think "statistically unique" is a well-defined term.
> The property of a ULA prefix is that there is a very low probability
> of collision if two ULA networks are merged. (For the details, see
> https://tools.ietf.org/html/rfc4193#section-3.2.3).

Thanks for pointing this --. I stand corrected.

(Must say, anyway, that things like " Globally unique prefix (with high 
probability of uniqueness)." leads to some confusion).

Possibly dumb question, since I wasn't there: what was the reason for 
carving ULAs out of the GUA space?  -- i.e., not updating the addressing 
architecture, and marking the ULA block as something other than GUA.

Thanks!

Regards,
-- 
Fernando Gont
SI6 Networks
e-mail: [e-mail]
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