Fri, Jan 13, 2017 at 04:40:19PM +0900, Lorenzo Colitti:
But it's true that supporting /65-/126 increases the cost of the device.
The extra bits have to go somewhere. I think I've seen hardware that just
converted all prefixes to 128 bit if there was at least one /65 - /126
prefix in the FIB. That costs money for RAM. Obviously that's silly if
those prefixes are frequent, and you can save that money using better
software engineering - but software engineering costs money too.
do such limited devices really need complex ribs/fibs? address, router,
neighbors. all of which are needed regardless of the prefix length.
Prefixes
don't cost money,
but, they do: https://www.arin.net/fees/fee_schedule.html
and if we know that we won't run out of them
do we know this? and 640k RAM is plenty. i'm not convinced.
the problem?
rfc6164 s5.1, s5.2. s5.2 applies to your ram-limited devices. end users
that want to subnet can't w/o additional /64s.