[c-nsp] DNS amplification

Tue Mar 19 19:24:34 UTC 2013

Leo,

On Mar 19, 2013, at 11:57 AM, Leo Bicknell <bicknell at ufp.org> wrote:
> 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.  

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. 

> A LISP network is a similar model, with LISP nodes caching rather than linecards.

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.

Regards,
-drc