Posted: Sun, 02 October 2011
ARIN has changed the Whois query behavior on port 43. A query for an IP address in the ARIN region will return only that assignment/allocation within the ARIN region, and will no longer included ARIN's parent record (the /8).
Both the Whois web interface and Whois-RWS behavior were not affected by this configuration change.
Chief Technology Officer
American Registry for Internet Numbers (ARIN)