[.....]
Most L3 switches shipping today (e.g. the product in question)
have
particular ethertypes and destination address
offsets hardcoded into their
ASICs. It's not a
matter of supporting 128-bit addresses -- they simply
doesn't understand IPv6's header any more than they do DECnet or
AppleTalk.
While allocation policies may have an effect on how IPv6 FIBs
are most
efficiently stored, address length is a
fairly small part of the problem
when you're talking
about redesigning every ASIC to handle both IPv4 and
IPv6.
[....]
