nanog mailing list archives

Re: [c-nsp] DNS amplification


From: David Conrad <drc () virtualized org>
Date: Tue, 19 Mar 2013 12:24:34 -0700

Leo,

On Mar 19, 2013, at 11:57 AM, Leo Bicknell <bicknell () 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



Current thread: