North America Runs Out of IPv4 Internet Addresses

The American Registry for Internet Numbers has issued its last IPv4 number for North America. That means that anyone looking to get a number will now be entered onto a waiting list.

The transition from IPv4 to the newer IPv6 has already begun, but it still could cause headaches for some service providers going forward. In 2011, when several large companies got together to test IPv6 capabilities for 24 hours, only 0.25% of the web was compatible with IPv6, according to Wired.

IPv4 addresses are how most internet traffic is routed today. You've probably seen 198.168.1.1 or some variation listed as the IP address of your router. The 32-bit number limits the possible addresses to just over 4.2 billion, which probably seemed like a number that could never possibly be exhausted when the protocol went into use in the early 1980s.

Every internet-connected device has an IP number attached to it. The newer protocol, IPv6, uses 128-bit numbers, meaning there are a possible 340 undecillion addresses. Undecillion, despite not appearing as a valid option in spell-checkers, is a real, ridiculously huge, number: a one followed by 36 zeros.

However, with the end of unassigned IPv4 addresses comes changes in ARIN's transfer policies, meaning "there is no longer a restriction on how often organizations may request transfers to specified recipients."