Re: Start accepting longer prefixes as IPv4 depletes?

[David Conrad <drc () virtualized org>]

Cameron,

On Dec 8, 2010, at 12:01 PM, Cameron Byrne wrote:
> I believe a lot of folks think the routing paths should be tightly
> coupled with the physical topology.

The downside, of course, being that if you change your location within the physical topology, you have to renumber.  
Enterprises have already voted with their feet that this isn't acceptable with IPv4 and they'll no doubt do the same 
with IPv6.

> In a mature IPv6 world, that is sane, i am not sure what the
> real value of LISP is.

Sanity is in the eye of the beholder.  The advantage a LISP(-like) scheme provides is a way of separating location from 
identity, allowing for arbitrary topology change (and complexity in the form of multi-homing) without affecting the 
identities of the systems on the network. Changing providers or multi-homing would thus not result in a renumbering 
event or pushing yet another prefix into the DFZ.

> Then there is the question of who benefits from LISP
> and who pays.  The edge pays and the DFZ guys benefit (they deffer
> router upgrades).... i already pay the DFZ guys enough today.

Increased size/flux in the DFZ as a result of PI allocations, more specifics announced for traffic engineering, and 
multi-homing _will_ increase the cost to the "DFZ guys" as they have to upgrade their routers to deal with growth. It 
is unlikely they'll not pass that cost on to their customers.

Regards,
-drc