[c-nsp] Cat7600/Sup720 and IPv4 vs IPv6 performance

[Rick Ernst]

The specs for the Sup720/3BXL indicate support for 1,000,000 IPv4 routes
and 400Mpps. The numbers drop in half for IPv6 (500K routes,200Mpps)

I can't find information on how the routing/capacity is partitioned.  If I
run IPv6 are my combined IPv4 and IPv6 table limited to 500K routes?  Can
I carve out the memory so I can support a combination like 500K IPv4
routes and 250K IPv6 routes?  Will the platform mix and match v4 and v6 in
the same chunk of memory?  Same/similar question for a combined IPv4/IPv6
platform; if I run both protocols is the aggregate traffic limited by the
IPv6 specs?

I don't know much more about IPv6 than how it is spelled, and I need to
start hitting the books for it.  I've seen the IPv4 BGP table grow from
less than 100,000 routes 10 years ago to almost 300,000 routes now, but
don't have the same feel for IPv6.  I'm trying to get an idea of expected
lifetime/capacity when deploying new equipment.

Thanks,