NAIPR Message

Average utilization of Class B's 1.5% in Japan per IETF

Per <>,

Dead space in the /8 space 

Fifty-six /8 prefixes are currently allocated and approximately 18% of the
v4 space has been recovered. There are more addresses in the free pool than
18 months ago. 

In the /8 starting with 192, the recovery process found that most contact
information had email addresses that bounced when an attempt to contact was
made. In this space there exist truly legacy numbers used for local
addressable spaces long before the idea of private address space came into

JP-NIC has done a study of class B utilization with 464 class B networks in
Japan. Of the 770 technical administrators listed as contacts the survey
had answers from 246. The distribution of the number of hosts indicated
about 1,000 hosts per class B license. 

The survey found an amazing case where the designated contact was deceased
and the company holding the Class B license was out of business. Still, the
addresses were being routed. When the investigators went to the registry to
get the information updated they were reminded that they weren't the owners
of the record and that only the last contact of record could change the

submitted by pagans at


Larry Vaden <vaden at>