Back in February 2011, when the global Internet Assigned Numbers Authority (IANA) allocated the last blocks of IPv4 address space to the five regional Internet registries (that further distribute IP addresses), many experts warned of a fast approaching crisis that would severely affect Internet connectivity.

It was believed that the available IPv4 addresses would exhaust within months. But today, three years later, American Registry for Internet Numbers (ARIN) is still bestowing IPv4 addresses in the US and Canada. In an article titled Whatever happened to the IPv4 address crisis?, Lee Schlesinger, Network World’s former test center director shared his views on how far can we go this way and why the IPv6 adoption rate is still slow.