The industry’s transition from IPv4 to the IPv6 address scheme seems well underway, with Akamai reporting 460 times more IPv6 address requests in June than in the year prior. In a blog posting, CDN provider Akamai claims it saw 3.4 billion IPv6 requests across a single day—June 6, 2012, or World IPv6 Launch Day—versus just 8.3 million a year ago. Akamai tracked just under 19 million IPv6 addresses, compared to 280,000 a year ago, a 67-fold increase. In part, that's because a larger portion of the Web enabled IPv6, and unlike a year ago, left it on. On June 8, 2011, Web site operators enabled IPv6 for a day. In 2012, ISPs and providers of consumer-networking equipment joined Website operators in enabling the address scheme, which helped prompt the spike in addresses and requests. Turning on IPv6 support within the ISP community was one of the three primary drivers for IPv6 traffic growth, along with end-user device support and Website operators "dual-stacking" their content, or enabling it for both IPv4 and IPv6. IPv6, of course, has become a necessity because of the scarcity (and in some cases, exhaustion) of IPv4 addresses, the basic "phone numbers" of the Web. IPv6 uses 128-bit addresses, allowing for 2128, or approximately 3.4×1038 addresses. IPv4 uses 32-bit addresses, allowing for only 4,294,967,296 unique addresses worldwide. In Feb. 2011, the Internet Assigned Numbers Authority exhausted its free blocks of IPv4 addresses, and APNIC, the RIR overseeing the Asia-Pacific, ran out soon after. (ARIN, overseeing the Americas, is expected to exhaust its IPv4 pool about June 2013.) Although recent measures have begun to return unused IPv4 addresses to an IANA-managed pool, as well as provisions to sell or transfer them to other parts of the world, these are usually seen as stopgap provisions. Still, Akamai said that it had seen just a small percentage of site requests being made over IPv6, ranging from 0.5 percent to over 3 percent on a global basis. Sites will naturally see a higher IPv6 preference if they have more end-users with IPv6 connectivity from their network providers (such as with audiences in particular geographies) or with more device support, the company noted. About 65 ISPs also participated in the June launch, including AT&T, Comcast, and Time Warner Cable In fact, Verizon topped the list of ISPs with the most IPv6 requests, at 38.1 percent, followed by AT&T, with 18.1 percent. The support of U.S. ISPs also probably drove the United States to the highest IPv6 penetration, with 73 percent of the native address penetration, according to the Akamai report. What impact has or will IPv6 have on the data center? In general, that headache will be handled by products like the Cisco Carrier Routing System (CRS) family and competing products, which essentially serves as the gateway to the data center. Cisco said that it has emulated 60 million IPv4 to IPV6 translations from 1 million subscribers, all running concurrently in the system. Native end-to-end IPv6 support, of course, will eliminate the need for tunneling.   Image: Sabino Parente/