Subject: Re: IPv6 addresses really are scarce after all

From: "Stephen Sprunk" <[email-masked]>
Date: Wed, 19 Sep 2007 14:55:17 -0500

Thus spake "Tony Finch" <[email-masked]>
> On Tue, 28 Aug 2007, Thomas Narten wrote:
>> As a data point, ARIN (in the last year) adopted a IPv6 PI for
>> end sites doing multihoming policy. Such end sites get a /48.

FWIW, technically the PI policy also covers folks that are single-homed, 
though the bar is higher for them to get a block.  It's not expected that 
many single-homed sites will bother getting one, though; if so, and it 
becomes an operational problem, we'll raise the bar even higher.

> I thought that routes in the IPv6 DFZ were not supposed to be more
> specific than /32.

Back when the IETF was trying to stuff the operational world into TLAs and 
NLAs, completely ignoring the need of folks to multihome or do BGP-based TE 
(i.e. intentional deaggregation), that was the supposition.

The reality is that routes longer than that (I've seen /128s, for that 
matter) are accepted, up to /48 in general practice.  ARIN compromised at 
/48 for PI because (a) that's what a "site" is supposed to get according to 
the IETF, and (b) it makes it easy to filter them all out if they ever 
become a problem for the DFZ.  The IETF conveniently told vendors that they 
should not wire specific prefix lengths into hardware, so this hasn't 
resulted in any problems like we saw when CIDR was introduced.

S

Stephen Sprunk         "God does not play dice."  --Albert Einstein
CCIE #3723         "God is an inveterate gambler, and He throws the
K5SSS        dice at every possible opportunity." --Stephen Hawking 

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From: "Stephen Sprunk" <[email-masked]>
Date: Wed, 19 Sep 2007 15:02:01 -0500

Thus spake "John C Klensin" <[email-masked]>
> Second, the notion that RIRs set addressing policy is one that
> has not been in place forever.  Indeed, it has evolved very
> slowly and mostly by assertion by the RIRs that they have that
> authority --assertions that, in other contexts, might look a lot
> like either filling a vacuum or turf grabs depending on one's
> perspective.  While they have always (since there have been
> RIRs) had broad discretion within their own regions, and it has
> always been recognized some coordination discourages
> forum-shopping and other bad behavior, global address policy was
> historically set by IANA in conjunction with the IAB, not by the
> RIRs (although I assume their advice was certainly welcomed).

My understanding of the current process is that IANA policy is dictated by 
getting all RIRs to pass equivalent policies telling the IANA what to do. 
The NRO fits in there somewhere, as does US DoC.

> I also believe that the RIRs have some obligation to consult the
> IETF before making a major policy change and to pay careful
> attention to anything rational the IETF has to say.

The RIRs do look to the IETF for guidance.  However, they apparently feel 
free to declare the IETF's guidance not "rational", to use your word, and go 
out on their own when needed to meet the community's needs.  There is a key 
difference between advice and authority.

S

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From: "Stephen Sprunk" <[email-masked]>
Date: Wed, 19 Sep 2007 15:02:01 -0500

S