[ipv6-wg] RIPE Policy vs IETF RFC

On 13 Jun 2016, at 11:36, Nathalie Trenaman <nathalie at ripe.net> wrote:

> Hi Ole, Gert, David and Roger,
> 
>>> 
>>> In practice, this means that the RFC suggests that a customer can get an IPv6 assignment of any size, while the RIPE policy says the minimum should be a /64.
>>> I’m interested to know what the community thinks about this and if alignment between this RFC and the RIPE policy is needed.
>> 
>> That is an interpretation of RFC7608 that I hope is not common.
>> RFC7608 is written for the purpose of ensuring that forwarding engines (and routing protocols) are built so that they can handle any prefix length. Apparently some implementations treated IPv6 as classful, and only supported forwarding of prefix lengths from 0-64 and 128. RFC7608 has absolutely nothing to do with end-site address assignment. The IETF consensus on that is in RFC6177.
>> 
>> Best regards,
>> Ole
> 
> Thanks for your clarifications. The reason why I brought this up on the list, is that this RFC caused some discussion internally and externally and I wanted to verify that we’re all still on the same page.
> I agree that routing and end-site address assignment are two different things and I’m happy to see we are in agreement. 

Please excuse me while I delurk.  The following text is from RFC 4291:

   All Global Unicast addresses other than those that start with binary
   000 have a 64-bit interface ID field (i.e., n + m = 64), formatted as
   described in Section 2.5.1.  Global Unicast addresses that start with
   binary 000 have no such constraint on the size or structure of the
   interface ID field.

That is written without MUST or SHOULD, and has been at least partly overtaken by RFC 6164 ('Using 127-Bit IPv6 Prefixes on Inter-Router Links', though 6164 is not noted as updating 4291), but it does seem a very definite statement.  Has it been modified anywhere else?

Sam

-- 
Sam Wilson
Communications Infrastructure Section, IT Infrastructure
Information Services, The University of Edinburgh
Edinburgh, Scotland, UK


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