Subject: RE: Making ND Optional [Was RE: draft-ietf-ipv6-cellular-host-00. txt -> wg last call?]

From: "Karim El-Malki (ERA)" <[email-masked]>
Date: Tue, 5 Mar 2002 18:58:18 +0100

> Karim El-Malki wrote:
 > > No, the router doesn't allocate any addresses on the
 > > "delegated" prefix.
 > > That was the assumption behind our 3gpp-advice draft and has
 > > been followed
 > > by 3gpp.
 > 
 > The router has to allocate at least 1 address in the prefix, 
 > even if it
 > is just the all-routers address. It is also likely to create 
 > another one
 > that is unique to itself,

This special router is called a GGSN and it knows it MUST NOT configure
itself with a unicast address on that prefix. That means there's no
conflict. Does that make sense?

/Karim
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From: "Tony Hain" <[email-masked]>
Date: Tue, 5 Mar 2002 11:12:43 -0800

> conflict. Does that make sense?

I will grant you that I don't know (or want to know) the inner workings
of a GGSN, but what is the point of a link with only one node? Where
does an origin send data if there is no other device to receive it? If
there is another device (assuming for a moment that the GGSN is the
second device), how does the origin find it unless that device uses an
address in the range the origin considers to be in this prefix? If that
second device uses an on-link address, how do the nodes at either end
know that there will never be a conflict (easy with out-of-band
coordination)? If either end generates RFC-3041 addresses, how does that
node ensure that the other end hasn't already used that bit pattern
(easy if only one end generates, and the other only uses EUI-64s with
bit 6 set)? If a GGSN really MUST NOT configure itself into a prefix
that is allocated to a client device, what is the point of a GGSN?

Does that make sense?

Tony

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From: Erik Nordmark <[email-masked]>
Date: Tue, 5 Mar 2002 23:10:44 +0100 (CET)

> conflict. Does that make sense?

What about a link-local address? Those are required on all interfaces.
And the RAs sent by the GGSN must have a link-local source.

Is the assumption that the link-local address of the router will
never conflict with the link-local address that the host picks e.g. by
relying on PPP to negotiate the interface ID?

  Erik