In message <5.1.0.14.2.20011128081413.00aa29f0@localhost>, Philip Smith writes:

My theory is that DISO-UNRRA were originally allocated 132.1.0.0/16 through 132.15.0.0/16 in the classful world - these are all in the ARIN DB under various military guises. When CIDR came along, it seems that someone must have decided that because 132.0.0.0/16 was now available and part of a bigger block, it could be added to the announcement, etc...?

There are a total of four like this:

Network Origin AS Description 132.0.0.0/10 568 DISO-UNRRA 135.0.0.0/13 10455 Lucent Technologies 137.0.0.0/13 568 DISO-UNRRA 158.0.0.0/13 568 DISO-UNRRA

Umm -- how does Lucent fit into that? Last I checked, it wasn't part of DoD. Back in the mists of time, AT&T was allocated what we would now call 135.0.0.0/8. We allocated addresses according to what seemed like a rational scheme at the time, this being pre-CIDR. But a wandering neutron struck our CEO, inducing a fission event that produced (among other particles) AT&T and Lucent. 135.0.0.0/8 was split between the two companies as a collection of /16's, on the reasonably rational grounds of "whoever is using the block gets to keep it". This minimized disruption (or rather, avoided further disruption), at a time when there was plenty of other chaos involved in splitting companies, networks, buildings, and organizations. Unfortunately, it did not happen to correspond to CIDR principles, but as I said, the allocation to AT&T antedated CIDR and in no way anticipated what the CEO and the Board of Directors was going to do.

From 135.207.0.0/16,

--Steve Bellovin, http://www.research.att.com/~smb Full text of "Firewalls" book now at http://www.wilyhacker.com