[arin-ppml] Does Moore's law help with routing table growth?

Scott Leibrand scottleibrand at gmail.com
Wed Dec 23 00:25:47 EST 2009

On 12/22/2009 8:31 PM, Michel Py wrote:
>> Scott Leibrand wrote:
>> If we just raised the prices of ASNs, multihoming with
>> private ASNs would become a lot more popular.
> We may be agreeing on this, but I feel the limitations of my English
> here.

You hide any such limitation well.  :-)

>   I must have missed a step; how does multihoming with private ASNs
> work?

Our mutual customer runs BGP with both of us, uses a private ASN to run 
BGP, and announces both of us his route.  We both implement the 
remote-private-as command (or equivalent) to strip his private ASN from 
the path before announcing it to our providers and peers.  As a result, 
the BGP table contains the route with two different origin ASNs: mine 
and yours.  That's ugly, but it doesn't really break anything.

> Besides, ASNs are not in short supply, slots in the routing table are
> problematic. How would raising the price of ASNs would prevent people
> from announcing a gazillion prefixes from one ASN?

Exactly correct.  Which is why any viable method would have to monetize 
the routing slots directly, for example by tier 1 transit providers 
charging their customers per route announced, and adding deaggregation 
ratio requirements to their existing traffic ratio requirements in their 
peering agreements with each other.  Which won't happen unless the rate 
of growth of the routing table becomes a much more significant problem 
than it is today, or router capacity growth dramatically slows.


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