No more IPv4 addresses available in United States and Canada, Whats next?
According to ARIN, IPv4 dates back to 1981 and has room for only 4.3 billion unique addresses.
Introduced in 1999, IPv6 should have enough addresses to serve Internet users for generations.
IANAs primary pool of IPv4 addresses was exhausted in February 2011.
As another option, firms looking for IPv4 addresses can sign up with ARIN to find a willing participant.
This event has led to a change in the organizations rules for approving transfers.
Other RIRs are also running low on IPv4 addresses.
source: www.techworm.net