Subject: Re: SUMMARY: RE: Limiting the Use of Site-Local

From: Thomas Narten <[email-masked]>
Date: Mon, 04 Nov 2002 14:32:54 -0500

> There are been other posts contributing this, which I agree with:
> - Not globally routable.
> - No registration.
> - No cost.

Good start.

What about globally unique? Not immediately clear one can get
uniqueness without some sort of registration. But the registration
might be fairly painless.

> My personal view on this is that there needs to be some ambiguity as
> well, for two reasons:

I don't follow what you mean by "ambiguous".

> a) Ambiguous addresses would obviously be a smaller block which in turn
> would be a lot easier to obtain from IANA; you know this part a lot
> better than I do so I'd be happy to hear your views about this.
> b) Ambiguous addresses are a guarantee that they will never be globally
> routable because the block is too small.

Well, there are no guarantees, but if there was a chunk of address
space reserved for "globally unique, but no expectation that it will
ever be routed on the public internet", and it came out of a well
known prefix, I'd expect that enough ISPs would filter on them to keep
them from being usefully routable in a global sense.

Thomas
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From: "Michel Py" <[email-masked]>
Date: Mon, 4 Nov 2002 11:28:36 -0800

Thomas,

>> Michel Py wrote:
>> There is ample evidence to support the fact that the
>> customer (the network administrator) wants, if not
>> site-local, at least something that provides what
>> site-local does; and that they will continue using
>> them the way they see fit regardless of the fact that
>> the IETF could try to restrict their use or not. Keep
>> the customer happy.

> Thomas Narten wrote:
> It would be good if this WG could come to some sort
> of understanding/consensus of what it is that the
> "customer" wants per the above "something that provides
> what site-local does".
> [snip]
> - provide a better solution that meets the actual needs
> without necessarily even using SLs.

I believe this would be fine with many, as I can't recall anybody that
supported site-locals doing it for the site-locals themselves but for
what they provide, see below.

> Do you have some specifics you can cite here?

In short, I think that if there was a /32 allocated to private
addressing, that is strongly labeled "do NOT route on the public
Internet", we might find that most networks administrators could not
care less about site-locals.

In order not to make this RFC1918-bis, we also need a mention that
strongly states that these addresses are not to communicate with the
public Internet in any form or fashion; read my lips: no NAT.

Michel.

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From: Margaret Wasserman <[email-masked]>
Date: Tue, 05 Nov 2002 18:09:13 -0500

>care less about site-locals.

This wouldn't actually be any different than site-locals, except
for being a /32 instead of a /9 or /10, or whatever site-locals
are...

The main problems with site-locals are caused by the fact that the
same site-local prefix is used in multiple sites, creating ambiguity.
Additional problems are caused by the assumption that a single host
may be in more than one site at the same time (creating even more
ambiguity).

Changing what number we use for the prefix and/or the length of
the prefix doesn't change anything...

Margaret