IPv6 /64 links (was Re: ipv6 book recommendations?)

Sat Jun 23 04:49:03 UTC 2012

On Fri, 22 Jun 2012, Masataka Ohta wrote:

> Unlike IPv4 with natural boundary of /24, routing table
> explosion of IPv6 is a serious scalability problem.

I really don't see where you're getting that from.  The biggest consumers 
of IPv4 space in the US tended to get initial IPv6 blocks from ARIN that 
were large enough to accommodate their needs for some time.  One large v6 
prefix in the global routing table is more efficient in terms of the 
impact on the global routing table than the patchwork of IPv4 blocks 
those same providers needed to get over time to accommodate growth. 
Those 'green-field' deployments of IPv6, coupled with the sparse allocation
model that the RIRs seem to be using will do a lot to keep v6 routing 
table growth in check.

I see periodic upticks in the growth of the global v6 routing table (a 
little over 9k prefixes at the moment - the v4 global view is about 415k 
prefixes right now), which I would reasonably attribute an upswing in 
networks getting initial assignments.  If anything, I see more of a chance 
for the v4 routing table to grow more out of control, as v4 blocks get 
chopped up into smaller and smaller pieces in an ultimately vain effort to 
squeeze a little more mileage out of IPv4.

jms