Concerns grow over IPv6 migration

European businesses are being held back from migrating to IP version 6 due to the way IP addresses are being allocated, according to the director of IT at the UK internet registrar, Nominet.

IPv6 will succeed the current version, IPv4, and because it uses a longer string of numbers for identification, it promises many more IP addresses than are possible in IPv4.

The American Registry for Internet Numbers (ARIN) argues that because only 19 percent of IPv4 address space remains available — and it is running out faster than expected — it was, for the first time, "compelled to advise the internet community that migration to IPv6 is necessary for any applications that require ongoing availability of contiguous IP number resources".

Dave Passmore, research director at Burton Group, said: "This issue will significantly affect all enterprise organisations with applications that require the ongoing availability of public IP addresses."

However, concerns have been raised about the way IPv6 addresses are currently allocated by RIPE, the European equivalent of ARIN, and it appears that this situation will not change for at least four months.

Nominet's IT director Jay Daley indicated that, unlike ARIN, RIPE was allowing only ISPs access to IPv6 addresses, leaving enterprises out in the cold. "We, for example, have our own IPv4 address allocation from RIPE, but we are unable to get an IPv6 allocation because their current allocation policy means we must be an ISP who gives addresses out to at least 200 customers. We don't give addresses to customers — we are an enterprise, in the same way that a large enterprise might want their own address space for local management of internet connectivity."

"So we have all the infrastructure in place to support IPv6, but we are barely able to support it because we can't get the addresses. The allocation policy is geared towards ISPs, not enterprises," Daley continued. "Enterprises are basically in the position that they have to get their IP address allocation through an ISP. For many that's what they already do, but for those that would ordinarily get their own directly from RIPE — large organisations such as the BBC — this isn't suitable."

The allocation policy is geared towards ISPs, not enterprises

Jay Daley, Nominet

Daley's view was backed by Tim Chown, systems administrator for the University of Southampton's school of electronics and computer science and a member of the UK's IPv6 taskforce. Chown explained how, although the bulk of the hardware and software needed for IPv6 was already available, companies were currently unable to avoid being tied to an ISP when migrating to IPv6. "With IPv4 you have been able to get provider-assigned or provider-independent [PI] addresses," he said. "An enterprise could get PI addresses [to] connect to multiple networks, or to be able to change ISP without getting a new IP number. With IPv6, there isn't the equivalent on PI space. ARIN have an initial pilot, but the equivalent is not currently available from RIPE."

RIPE only submitted a proposal on PI IPv6 assignments on 22 May. As RIPE's policy development process takes a minimum of 19 weeks, this means it will take at least a further four months for companies to be able to apply for permanent IPv6 space without being tied to an ISP.

Daley and Chown also indicated other inhibiting factors for enterprise adoption of IPv6.

Daley said IPv6 was complex to understand in relation to IPv4 and that, in these early days, it remains unpredictable as to how network address translation equipment might handle IPv6. However, said Daley, hardware and operating system vendors — Windows Vista boasts broad IPv6 support — had "done their job already", and further progression in the great migration was now down to RIPE.

Chown highlighted another problem that might be faced by IT managers wishing to migrate their organisations to IPv6. "One issue is how to deploy IPv6 along IPv4. What has been suggested until now has been that sites or enterprises support both protocols. While you learn IPv6, running a dual stack allows you to build those skills and look at the issues, but the problem with that approach is that it still requires that you have IPv4 addresses — which only works [until IPv4 space runs out]. It is also difficult to justify doing that if there are very few other networks that are — it is a question of who would move first. Also, if you run a dual stack then your operational costs are likely to rise [while] you are supporting two versions."

In the meantime, said Chown, IPv4 space is running out fast. "Even the most cautious [estimates for IPv4 depletion] used to say 2015. They are now saying 2010, 2011."