Subject: Re: I-D ACTION:draft-hain-ipv6-ulac-00.txt

From: Brian E Carpenter <[email-masked]>
Date: Tue, 14 Jul 2009 16:43:33 +0100

Hi,

>    It is expected that network administrators of larger organizations,
>    or those with business practice or governmental requirements to avoid
>    conflict in future mergers or acquisitions will prefer central
>    allocations, 

I don't expect that at all. Why make such an assumption, and the
subsequent recommendation, rather than just state the choice in neutral
terms? IMHO this whole paragraph needs to be rewritten in a neutral style.

Something like:

As quantified in Section 3.2.3 of [ULA], there is a very small but
non-zero probability of two Locally Assigned ULA prefixes being equal.
Network administrators who are concerned by this may prefer central
allocations. In particular, network administrations which are planning
to use Local IPv6 address prefixes for extensive inter-site communication
over a long period of time could use a Centrally Allocated prefix, as
there is then mathematically no possibility of allocation conflicts when
interconnecting or merging networks. Individual administrations are free
to choose either approach, and in fact could choose both, with a Centrally
Allocated prefix for their production networks while using locally assigned
prefixes in their experimental or lab networks.

    Brian

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From: Thomas Narten <[email-masked]>
Date: Tue, 14 Jul 2009 11:58:10 -0400

Tony,

Could you provide some background on:

1) why reissue this document at this time

2) what has changed in the document relative to previous versions?

Finally, IMO, based on previous discussions, this document is/was
effectively dead. There has always been a lot of controversy with
C-ULAs, and there simply hasn't been consensus to move the document
forward. What has changed since the last time the WG had a discussion
about ULAs? Is there some new information we should be considering?

I do not think it is particularly useful (or pleasant) to have a
replay of old positions on this topic, if in fact, no minds will
change. So unless there is a compelling reason to revisit C-ULAs at
this time, I'm not at all sure we need to have this discussion yet
again.

Thomas

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From: "Tony Hain" <[email-masked]>
Date: Wed, 29 Jul 2009 14:43:53 +0200

> this time, I'm not at all sure we need to have this discussion yet

The RIRs have collectively developed PI allocation policies, where lack of
those was the primary source for complaints before. Second enterprises are
becoming more aware, and really - really - really believe they need private
space, no matter what the outside world thinks is 'right'. M&A worries make
ULA-L inappropriate, and fighting with an RIR over private use of a PI
prefix is not something they want to do.

Bottom line, this is a hole in the address architecture that needs to be
filled. There is no reason for the IETF to dictate to others what they can
do in their private network. The only thing this document is doing is
setting up the range, as actual implementation and policies related to
registration are delegated to the allocation authority. 

Tony