v6 subnet size for DSL & leased line customers

Sun Dec 23 06:07:56 UTC 2007

Randy Bush wrote:
>> There is a huge detent at /48
> 
> other than the perennial operational pontification from on high by the
> gods of the ietf (brought to us by the folk who brought us the wonderful
> TLA, NLA, etc. classfulness++), could you elucidate?

>From one angle, last time I looked, the RIRs were converging on that as
acceptable minimum for a single PI allocation.

/48 is a large enough block that single site however you choose to
define that, is not going to have to renumber out of it due to inability
to subnet.

If you mean there's no detent between /48 and /56 wouldn't you a
wholesale operator determine that based on the need and guidance from
your rir? We do not in ipv4 land just hand out /19s and /20s to
customers until we can go back to arin for another /12...

If you're asking why ipng doesn't incorporate the lessons of cidr
(they're both responses to the same problem), then you tell me, you were
there and I was in high-schol.

> randy
> 