The pool of available IPv4 addresses—Internet Classic—is entering its final phase of depletion, according to North America’s regional Internet registry. This does not mean that IPv4 will be disappearing any time soon, but it does mean that growth in the Internet will require adoption of the next generation IPv6 addresses, or that organizations will have to bargain for unused old addresses on a secondary market.
The pool of available IPv4 addresses—Internet Classic—reached another milestone on its road to depletion this month, when ARIN, North America’s Regional Internet Registry, announced that it was unable to fully accommodate a request for a block of new addresses from its shrinking pool. This triggered for the first time its “unmet requests policy,” in which customers looking for relatively large blocks of IPv4 addresses will either have to make due with a smaller block or be wait-listed.
“ARIN does still have limited amounts of IPv4 address space available in smaller block sizes,” the registry announced. But the number now is so small that it will be increasingly difficult to get allocations and the pool expected to pretty much dry up this summer.
This means that Internet growth will increasingly come with the adoption of next generation Internet Protocols, IPv6, or users will have to go into the secondary marketplace for unused (and probably expensive) IPv4 addresses.
Because of the 32-bit format of the numerical IPv4 addresses, there were only 4.3 billion distinct Internet addresses available. IANA, the Internet Assigned Numbers Authority, which oversees IP address allotments, distributed the last remaining wholesale blocks of these addresses to the five regional registries in 2011. Each of these /8 blocks contained one-256th of the entire address space, or 16,777,216 addresses. These were retailed in smaller blocks to large Internet companies and other organizations.
ARIN now has little more than half a percent of its final /8 available, or fewer than 91,500 IPv4 addresses.
The switch to IPv6 has begun, but because there is a global infrastructure already built on v4 the transition still is in its infancy. And because so many v4 addresses were allocated in large blocks, there still are a lot of them that are not actually in use. A secondary market for unused addresses is developing for those who want to extend their existing infrastructure as long as possible before making the move to IPv6.
According to IPv4Auctions.com, a marketplace run by Hilco Streambank, addresses have been going this year from $7.45 each to more than $10 each, with most somewhere in the $8 range, depending on the size of the purchase.
But given that new IPv6 addresses are available for free and everyone eventually will have to move to IPv6 anyway, it’s hard to see this secondary market for v4 addresses persisting for too long. Most software and hardware today supports the new protocols, and big Internet companies will grow tired of supporting both protocol stacks. Probably sooner rather than later they will shut down IPv4 and move exclusively to v6. IPv4 will still work (mostly), but it will become increasingly kludgy, and soon a tipping point to IPv6 will be reached.
There still are significant issues of security and administration to be worked out in moving to IPv6. But unless your organization already has a large supply of IPv4 addresses or has very deep pockets, you probably would be better served by addressing these issues now rather than putting it off in the secondary market.