Re: Last Call: <draft-ietf-6man-rfc2460bis-08.txt> (Internet Protocol, Version 6 (IPv6) Specification) to Internet Standard

[Sander Steffann <[e-mail]>]

> Op 26 feb. 2017, om 14:05 heeft Fernando Gont <[e-mail]> het volgende geschreven:
> 
> On 02/26/2017 09:55 AM, Sander Steffann wrote:
>> Hi,
>> 
>>> 2.3.  Address Type Identification
>>> 
>>>  The type of an IPv6 address is identified by the high-order bits of
>>>  the address, as follows:
>>> 
>>>     Address type         Binary prefix        IPv6 notation   Section
>>>     ------------         -------------        -------------   -------
>>>     Unspecified          00...0  (128 bits)   ::/128          2.4.2
>>>     Loopback             00...1  (128 bits)   ::1/128         2.4.3
>>>     Multicast            11111111             ff00::/8        2.6
>>>     Link-Local unicast   1111111010           fe80::/10       2.4.6
>>>     Global Unicast       (everything else)
>>> 
>>> 
>>> I wonder if this table should explicitly call out ULAs, and provide a
>>> reference to the corresponding section.
>> 
>> ULAs are not an address type, they are Global Unicast. Adding them here might confuse people. And if we include ULAs then there is lots more that we should include as well. So while I understand your question, I think it would be better not to.
> 
> The "confusing" part is that, while globally unique, their scope is not
> really global -- i.e., they are not meant to be globally routable.

Indeed, globally unique vs globally routable. But if you go into this then it's more complicated than it seems. Whether something is routable and where are an operational choice. Companies choosing to interconnect might route each other's ULA space, while some of my RIPE NCC allocated space is not routed anywhere public. It's difficult to give a fixed definition that doesn't take operational stuff into account.

Of course the intention of how to use ULA should be mentioned somewhere, but probably not in this table.

> Wasn't there at some point an I-D aiming to clarify what "global" meant?
> -- IIRC, authored by Brian et al.

Sorry, I don't remember.

Cheers,
Sander