> In a message written on Tue, Mar 19, 2013 at 11:33:33AM -0700, David
>> LISP doesn't replace BGP. It merely adds a layer of indirection so you
don't have to propagate identity information along with routing topology,
allowing much greater aggregation.
> The problem with LISP is that when the complexity of the entire
> system is taken into account it is not signficantly more efficient
> than the current system.
When was the last time you (as a network operator) cared about the
efficiency of the entire system?
LISP (and similar) system are inherently more complex because they're
adding a new element to the network -- TANSTAAFL. The point is that the
complexity is added at the edge where it is easy/cheap (per node or site).
Yes, entire system complexity goes up. However from the perspective of the
core where life is fast/expensive, complexity goes down since identity is
separated from location.
As I see it, that is the fundamental problem with LISP. It wants edge
investment to solve a core problem. I don't carry full routes in my core,
but LISP wants me to do something to solve a problem I don't have. And,
that something looks a lot like an ATM SVC (dynamic tunnels ?)
That said, IMHO, ILNP is a lot more interesting in the locator / id split
space.... As well as general evolution of internet architecture. LISP just
has had better marketing and simpler code.
Ya know, this problem would also largely be solved if everyone just
switched to ipv6 and stopped using those disjointed tiny v4 blocks.
Oh, but that would break Skype. Nevermind.
> A LISP network is a similar model, with LISP nodes caching rather than
You're comparing the equivalent of a DNS lookup with a FIB lookup. Yes,
there is a performance hit when you do the mapping of identity to location
(TANSTAAFL), however this is at the edge in the millisecond DRAM-stored
connection initiation world, not in the core in the nanosecond SRAM-stored
packet forwarding world.