192/8 (was Re: NSP ... New Information )

Suzanne Woolf woolf at ISI.EDU
Mon Jun 9 01:16:28 UTC 1997


> And yes, there is an incentive to return space.  For some its the principle
> of the thing, a cooperative internet is a growing internet. For others it
> may be financial, with the expense of renewing lease delegations. (See the
> naipr/arin lists for more details).

In conversation with some NANOG participants last week I was asked
more than once for clarification or further details about 192/8,
continuing from Bill's remarks Friday.

It does seem that 192/8 isn't the concern it was eighteen months ago.
One reason is that some carriers now refuse to route legacy 192/8
delegations for new customers, requiring instead that they renumber
into provider space.  Folks holding delegations but not yet trying to
route them were never an enormous number of prefixes but looked for
awhile like they might be a significant contributor to routing table
growth; back-of-the-envelope calculations a little while ago suggest
this potential doesn't seem to have materialized (it's hard to be sure
because routing table announcements don't have origin dates, but
there's some reason to believe new announcements are simply better
aggregated than older ones, even in 192/8).

An informal survey: how many NANOG participants have asked customers
to renumber out of 192/8?  And for how long have you been doing this?

IMHO the remaining major obstacle to a concerted effort at reclamation
in 192/8 is the database maintenance problem.  Folks with no incentive
to keep their whois entries current have not been doing so-- since the
typical pre-CIDR "Class C" delegate was not an ISP and has never come
back for more space, the registries have limited leverage over them,
with a few notable exceptions such as DDN-NIC.  Accordingly, "whois"
contact information simply doesn't tell you who's using a block.  I
haven't risked a blind survey again since the first one, but I have no
reason to believe this has changed-- any takers?

I hope and expect that ARIN may be able to throw some organized effort
at this problem, if the membership feels that cleaning up the database
is important.


Suzanne Woolf
woolf at isi.edu
(ISI pays me to run routers'n'DNS'n'things, 
my opinions are mine)



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