In a message written on Tue, Mar 19, 2013 at 11:33:33AM -0700, David Conrad wrote:
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. Even if it works perfectly, it makes no economic sense to spend the time and money to swap out the current system for something with approximately the same scaling properties and costs going forward. Any replacement would probably have to be an order of magnitude better at least to justify the pain of switching. LISP also has some potential downsides at Internet scale. Those who remember the 7500 platform when caching was the rage know what happens when you have to flush the cache for example. A LISP network is a similar model, with LISP nodes caching rather than linecards. There is potential for distributed uglyness. However, the LISP folks made a rather smart course correction in my opinion, and one I never would have thought to make. The LISP testbed network proved that LISP was a nice way to overlay an arbitrary topoligy on top of the existing Internet. Compared to many other "VPN" solutions it has a lot of nice properties. Some folks are now using LISP to network a collection of sites using commodity internet access making very resiliant topologies quickly and easily. I suspect LISP may find a very productive niche. -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/