IPv4 BGP Table Reduction Analysis - Prefixes Filter by RIRs Minimum Allocations Boundaries

Jon Lewis jlewis at lewis.org
Fri Dec 21 21:10:25 UTC 2007

On Fri, 21 Dec 2007, Greenhalgh, John wrote:

> For example, we have a /19 allocated from APNIC and announce this from
> our Hong Kong network. Within that /19 we have assigned a /21 to our
> Australia site which is discontiguous from Hong Kong. This /21 is
> announced upstream to two ASes, and being in the 210/7 block would be
> filtered.
> We have several discontiguous networks around the world and when these
> sites started it could not be justified to use a min RIR allocation for
> the site.

That's unfortunate, but your problem doesn't scale.  If every network got 
an RIR allocation, and then subnetted it among several discontiguous POPs 
and polluted the global route table with those subnets, the routing table 
would be even worse than what we have today.  How much are you willing to 
pay every other network to carry your deaggregates?  What makes your 
deaggregates special and more worthy of a free ride than any other 
deaggregating network?

With the holiday and new years fast approaching, and our upgrade kits not 
quite fully assembled (much less tested), I just filtered you (before 
seeing your message) as we're now filtering APNIC on "RIR Minimums".  We 
were just 2399 routes away from our Sup2s doing bad things.  Now we're 
20306 routes away...which leaves a much more comfortable margin of safety.

Looking forward to seeing your routes early next year...after we've 

  Jon Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
_________ http://www.lewis.org/~jlewis/pgp for PGP public key_________

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