On Thu, Nov 19, 1998 at 09:34:09PM +1300, Craig Anderson wrote:
Anything longer than /24 is not very routable (Sprint for one doesn't accept routes longer than /24), so /24 is the usable limit. I have no problem with a statement saying blocks smaller than /24 are not portable.
MCI, Telstra, Teleglobe and Concentric also refuse any advertisements
with a longer prefix than 24.
There is another good reason to avoid >24 portability - DNS.
In-addr.arpa zones for smaller networks are inherently unportable under
the prevalent scheme for finding PTR records, which presupposes delegation
based on octet boundaries.
In other words, it is unreasonable to think that a customer could leave
ISP A for ISP B, taking her addresses with her, and expect ISP A to
maintain PTR records for her hosts with no recompense.
PTR records are worthwhile for a number of reasons, and we do not want
a policy which encourages people not to use them.
I think consensus on the fact that _any_ network prefix longer than 24
bits is not portable should be easy to reach. Anybody disagree with this?
(straw poll :)
Joe
--
Joe Abley