Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)

Fernando Gont <fgont@si6networks.com> Thu, 18 February 2021 20:05 UTC

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Subject: Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)
To: "Templin (US), Fred L" <Fred.L.Templin@boeing.com>, IPv6 Operations <v6ops@ietf.org>, "6man@ietf.org" <6man@ietf.org>
References: <7aa2337f8d1b4036a64b3d0d40374eb1@boeing.com>
From: Fernando Gont <fgont@si6networks.com>
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Date: Thu, 18 Feb 2021 16:52:48 -0300
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On 18/2/21 16:46, Templin (US), Fred L wrote:
[...]
>>
>> Hi, Fred,
>>
>> On 18/2/21 16:11, Templin (US), Fred L wrote:
>> [...]
>>>> On 18/2/21 14:37, Templin (US), Fred L wrote:
>>>>> Another aspect I failed to mention is that the use of (H)HITs does not
>>>>> necessarily  mean that all aspects of the HIP protocol must be used. (H)HITs could be
>>>>> used with the AERO/OMNI services instead, for example.
>>>>
>>>> Questions: Are these addresses globally-unique?
>>>
>>> Yes - global uniqueness is a key objective of (H)HIT. Aggregation is not within
>>> scope, however.
>>
>> If that's the case, then, according to RFC4007, they are global addresses.
> 
> I actually think HITs are a bit of a gray area. According to RFC7343, they are
> formed from the GUA prefix 2001:20::/28 but the remaining bits following
> the ::/28 prefix are cryptographically generated and hence non-aggregatable.

BUt according to RFC4007, the scope is defined by the topological span 
where the address is meaningful....


> That means that there is no way to represent a group of them in the routing
> system using any other prefix length than /128.

That's not a requirement when it comes to "scope".



>> (I'd argue that if they cannot be aggregated, that's because they
>> resulting "addresses" are not really topologically-dependent, in which
>> case you might probably argue that they are not addresses in the first
>> place :-) )
> 
> Not in terms of routing across the global Internet, no, because it would not
> scale to inject large numbers of /128's into the global Internet routing system.

The thing is that if they don't represent a location in the network 
topology, they don't seem to qualify as an address, anyway.

An address is supposed to be a topologically-dependent identifier -- 
i.e., to convey information of location ("where?").

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: fgont@si6networks.com
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492