Subject: RE: Summary Re: Proposal for site-local clean-up

From: "Brian Zill" <[email-masked]>
Date: Wed, 13 Nov 2002 13:51:31 -0800

Brian Carpenter writes:
> 3. Can't stop NAT's anyway. (several people).
> That may sadly be true, but we shouldn't publish
> specs that seem to encourage them.

I would argue the opposite -- *preventing* site-locals and globals from
co-existing encourages NAT.  We're better off today than we would be
with that restriction.

Case study: A site has a disconnected network happily using site-locals.
These addresses get embedded in all sorts of configuration scripts, etc.
Then they decide to connect to the Internet and get a global prefix from
their ISP.

Today: They just advertise the new global prefix alongside the
site-local prefix, all their hard-coded addresses continue to work.

With restriction on mixing site-local and global addresses: They need to
renumber their network and find all the places addresses have been
specified in config files and the like.  Or they could just use a v6
NAT.  Which do you think will happen?

--Brian

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From: Keith Moore <[email-masked]>
Date: Wed, 13 Nov 2002 19:48:54 -0500

> site-local prefix, all their hard-coded addresses continue to work.

and their apps break because they use globals when they should be 
using SLs, or vice versa.

yes, I've actually seen this happen.

Keith