From nanog-bounces+bonomi=mail.r-bonomi.com@nanog.org Wed Dec 8 15:36:44 2010
Date: Wed, 08 Dec 2010 15:34:47 -0600
From: Jack Bates <jbates@brightok.net>
To: David Conrad <drc@virtualized.org>
Subject: Re: Start accepting longer prefixes as IPv4 depletes?
Cc: NANOG list <nanog@nanog.org>> Cameron,
>
>> 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.
>I think the issue, and correct me if I'm wrong, is that LISP does not
address issues of traffic engineering? A lot of the additional routes in
DFZ are there specifically to handle traffic engineering.
The primary thing that a LISP-like approach accomplishes is the 'de-coupling"
of infrastructure and leaf networks. You can mess with either one, w/o
having any effect on the other.