IPv6 prefix lengths

Thu Jan 13 08:40:37 UTC 2011

Richard's employer is exactly the kind of organization that has not
been able to effectively multi-home their discrete branch-offices on
the IPv4 Internet, because RIR allocation policy set the bar for
receiving IPv4 addresses for those small locations just high enough to
steer us away from that "feature" or "problem," depending on how you
look at it.

If every Richard Barnes announces a few dozen /48s into the global BGP
table, it will not be long before the 300k+ IPv4 BGP table looks neat
and organized, and the CIDR Report will come out each week with a
message begging e.g. Starbucks to aggregate their coffee shop wireless
hot-spots, instead of shaming Bell South for having a large number of
de-aggregates for their substantial ISP business.

Most people do not know about the "multi-homing feature" designed into
IPv6.  Most people who do, seem to agree that it may not see enough
practical use to have meaningful impact on routing table growth, which
will no longer be kept in check by a limited pool of IP addresses and
policies that make it a little difficult for a very small network to
become multi-homed.

This may be another looming IPv6 headache without a sufficient
solution to set good practices now, before deployment sky-rockets.

-- 
Jeff S Wheeler <jsw at inconcepts.biz>
Sr Network Operator  /  Innovative Network Concepts