Subject: RE: Enforcing unreachability of site local addresses

From: "Michel Py" <[email-masked]>
Date: Wed, 4 Dec 2002 08:19:09 -0800

> Kurt Erik Lindqvist wrote:
> So the remaining question besides the PI issue would be
> to define "limit" then?

This is a little simplified. I would say the remaining question is how
to manage the risk they end up being a mess in the global routing table,
and scalability issues.

These are the issues why we don't currently have PI.

Michel.

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From: "Tony Hain" <[email-masked]>
Date: Wed, 4 Dec 2002 14:40:34 -0800

To address the subject line:
The only way to enforce unreachability is to make the prefix ambiguous,
and thereby remove the value of trying to propagate it. Any definition
of a globally unique space will have to discuss how it scales *when*
(not if) it gets announced into the routing system. 

Tony

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From: Keith Moore <[email-masked]>
Date: Wed, 04 Dec 2002 19:37:19 -0500

> The only way to enforce unreachability is to make the prefix ambiguous,

which in turn causes the set of problems that make us want to avoid 
site-locals.

maybe we don't need to 'enforce' unreachability as a matter of protocol.
for instance, there's no 'enforcement' of IP packets being routed to 
their destinations.  sometimes they're routed elsewhere (as in interception
proxies) but we've generally done okay without 'enforcement'.

Keith

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From: Keith Moore <[email-masked]>
Date: Wed, 04 Dec 2002 21:13:08 -0500

> If we don't enforce unreachability through ambiguity, we need to provide
> an alternative that won't crush the routing system.

I suspect we all agree that crushing the routing system would be bad .
It seems like the question is what mechanism (other than ambiguity) 
would be sufficient to prevent that happening.

Keith

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From: "Tony Hain" <[email-masked]>
Date: Wed, 4 Dec 2002 18:09:11 -0800

BTW: I am updating my geo draft based on the comments from the last
round, so hopefully it will have fewer places to throw technical rocks
at. 

Tony

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] 
> Sent: Wednesday, December 04, 2002 4:37 PM
> To: [email-masked]
> Cc: [email-masked]
> Subject: Re: Enforcing unreachability of site local addresses 
> 
> 
> maybe we don't need to 'enforce' unreachability as a matter 
> of protocol. for instance, there's no 'enforcement' of IP 
> packets being routed to

---

From: "Tony Hain" <[email-masked]>
Date: Wed, 4 Dec 2002 18:26:16 -0800

Keith Moore wrote:
> > If we don't enforce unreachability through ambiguity, we need to 
> > provide an alternative that won't crush the routing system.
> 
> I suspect we all agree that crushing the routing system would 
> be bad . It seems like the question is what mechanism (other 
> than ambiguity) 

I still believe the fundamentals of:
http://www.ietf.org/internet-drafts/draft-hain-ipv6-pi-addr-03.txt
are sound from an aggregation standpoint. Michele & Iljitsch have an
alternative that could be described as a derivative of the international
dial-plan:
http://www.ietf.org/internet-drafts/draft-py-multi6-gapi-00.txt

The problem is not defining approaches that have reasonable scaling
properties. It is getting agreement that we don't need a perfect answer.

Tony