[ppml] geo addressing

[Michael.Dillon at btradianz.com]

> This is hardly a corner case.  There are tons of companies built around
> the HQ and remote sales office model.  All of the VPN hype that you've
> seen over the last few years is precisely to help these people construct
> exactly these networks.

If those really are pure VPN locations, then the local
addresses are irrelevant because everything in the remote
sales office will likely be addressed using HQ addresses.
The HQ and the remote sales offices could achieve local
multihomed resiliency of access connections using geotop
addresses.

> It would seem to me that you're suggesting that there's no need for
> geotop addressing.

No, I'm suggesting that it is not necessary for a solution
to be an all-singing magic bullet in order for that solution
to be useful and worthy of implementation. Geotop addressing
will dampen the growth of the global route table by enabling
millions of small end medium enterprises to multihome at the 
local level without consuming global routing table slots.

Clearly, any solution aimed at small and medium sized companies
will not be optimal for larger ones and there will probably
be a threshhold where it does not work at all. That's why I
don't think geotop addressing needs to address every corner
case. It is another option in the toolkit that will work well
in some cases and not in others.

--Michael Dillon