Wednesday, July 22, 2015

North America Out of New IPv4 Addresses

Iljitsch van Beijnum:

ARIN, the American Registry for Internet Numbers, has now activated its “IPv4 Unmet Requests Policy.” Until now, organizations in the ARIN region were able to get IPv4 addresses as needed, but yesterday, ARIN was no longer in the position to fulfill qualifying requests. As a result, ISPs that come to ARIN for IPv4 address space have three choices: they can take a smaller block (ARIN currently still has a limited supply of blocks of 512 and 256 addresses), they can go on the wait list in the hopes that a block of the desired size will become available at some point in the future, or they can transfer buy addresses from an organization that has more than it needs.


The Internet Engineering Task Force (IETF) saw the eventual depletion of IP addresses looming in the early 1990s, so they set out to solve the problem and came up with a new version of the Internet Protocol. The old IP has version number 4; the new version is 6. IPv6 increases the length of IP addresses to no fewer than 128 bits—sort of like increasing phone numbers from 10 to 40 digits. As a result, the number of available IPv6 addresses is, for all practical purposes, unlimited.

The trouble is that, of course, old systems can only handle the IPv4 with its 32-bit addresses. That problem has pretty much been solved in the intermediate decade, and today virtually all operating systems can handle 128-bit IPv6 addresses—although some applications can’t or don’t handle them properly.

The main issue remaining is that most networks simply haven’t enabled IPv6 yet. Although turning on IPv6 is not as hard as some people think, it’s not entirely trivial either in larger networks.

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