2011/4/18 Lukasz Bromirski <lukasz@bromirski.net>:
LISP scales better, because with introduction of *location* prefix, you're at the same time (or ideally you would) withdraw the original aggregate prefix. And as no matter how you count it, the number of *locations* will be somewhat limited vs number of *PI* address spaces that everyone wants
I strongly disagree with the assumption that the number of locations/sites would remain static. This is the basic issue that many folks gloss over: dramatically decreasing the barrier-to-entry for multi-homing or provider-independent addressing will, without question, dramatically increase the number of multi-homed or provider-independent sites. LISP "solves" this problem by using the router's FIB as a macro-flow-cache. That's good except that a site with a large number of outgoing macro-flows (either because it's a busy site, responding to an external DoS attack, or actually originating a DoS attack from a compromised host) will cripple that site's ITR. In addition, the current negative mapping cache scheme is far from ideal. I've written a couple of folks with a provably superior scheme (compared to existing work), and have received zero feedback. This is not good.
We may of course argue that the current routers are pretty capable in terms of processing power for control-plane, but
We agree that the ability to move tasks from the router to an external control plane is good. BGP may get better at this as time goes on, too. -- Jeff S Wheeler <jsw@inconcepts.biz> Sr Network Operator / Innovative Network Concepts