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routing table go boom (was: Re: [c-nsp] DNS amplification)

On Mar 19, 2013, at 2:12 PM, Joe Abley <jabley at hopcount.ca> wrote:

> We've been saying "unconstrained growth bad" for BGP for years. Presumably we're not all insane. Where is the science?

I think there is a lot of fear around this topic.  I'm waiting to see the great meltdown at 512k fib entries in networks.  We saw the same  at 128k and 256k with some platforms.  The impact on 512k will be just as great if not larger, but also very transient.  

I've observed a great deal of asymmetrical BGP participants in recent years.  They send a set of routes, sometimes small for their own global good, but take only on-net or default routes from their providers.

There is also the fact that many traffic-engineering techniques are quite coarse due to the protocol design.  The days of using prepending and aggregation/deaggregation are still with us, even when more sophisticated methods (communities, etc..) exist.  I'm starting to decide that the real issue is that most people just can't route (including some major networks).  The system works because the broken part gets greased, but there are a lot of cosmetic and non-cosmetic defects that linger because people don't realize they are there or are a problem.  If you want data on that, including my minimalistic "faux" science, there is plenty to be had.

- Jared