Subject: RE: Comments on draft-ietf-ipv6-unique-local-addr-00.txt

From: "Christian Huitema" <[email-masked]>
Date: Fri, 29 Aug 2003 20:51:43 -0700

> Additionally, let us postulate that all three entities have a small
> population of hosts which must be accessible from the public networks,
and
> that those hosts must also be reachable from the local private
network.

The plan of record is that these publicly reachable hosts will have both
a local address and a global address. The global address will be derived
from a prefix announced by the ISP.

> Unless I have missed some essential clause in your description above,
we
> appear to have a failure mode, with a root cause of user neglect or
user
> error, in which the non-propagation requirement for unique-local
prefixes
> to the global routing table is likely to be violated.

Stuff happens. However, one ISP making a mistake does not have to
endanger the whole Internet. Any good ISP is suppose to filter routes in
the FC00::/7 prefix from its own BGP announcements, and to ignore prefix
in the FC00::/7 range that peer ISP might mistakenly advertise.

-- Christian Huitema

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From: "Alan E. Beard" <[email-masked]>
Date: Sat, 30 Aug 2003 01:33:45 -0400 (EDT)

Christian:

Thanks for the clarification. Please see inline for a few comments

> from a prefix announced by the ISP.
Yes, that is consistent with my interpretation. Even where this is the
case, however, the hosts and the routers in the local environment would
have knowledge of the global routes (perhaps a default only for most
devices)  and the unique-local routes advertised into the local routing
domain.  The routers are likely to distribute all known prefixes,
including those which cross the site boundaries.

> in the FC00::/7 range that peer ISP might mistakenly advertise.
Yup, you're absolutely right.  Perhaps we don't need the route black hole
after all, provided that the network administrators execute their tasks
fully and consistently. I wonder what the rest of the group think. I'm
going to shut up for a while and let some others get a word in.

Pekka? Tony? Ralph?

Regards,

AEB

-- 
Alan E. Beard <[email-masked]>
AEBeard Consulting; 4109 Chelsa Ln; Lakeland FL 33809
863.815.2529