The end appears in sight for the IPv4 Internet addressing system. At a ceremony in Miami later today the Internet Assigned Numbers Authority will allocate the last five blocks of Internet addresses that use the current Internet Protocol version 4.The end appears in sight for the IPv4 Internet addressing system. At a ceremony in Miami later today the Internet Assigned Numbers Authority will allocate the last five blocks of Internet addresses that use the current Internet Protocol version 4.

Earlier this week – when there were still seven blocks remaining – it allocated two to Asia Pacific Network Information Centre (APNIC), the regional registry which hands out Internet addresses to the A-Pac region, including Australia.

The blocks on offer each contain 16.8 million IPv4 addresses. In all, IPv4 allows for 4.3 billion addresses – 2 to the 32nd power. Nearly all are now in use or allocated.

A new addressing system, IPv6, is set to succeed IPv4 and will provide almost unlimited addresses – to be precise, 340 undecillion, or 2 to the 128th power. Put another way, there could be exactly 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses.

As Internet service providers run out of IPv4 addresses, they’ll have to give subscribers IPv6 addresses. However the changeover will be a prolonged and tricky affair, sinceIPv4 and IPv6 are essentially incompatible, and right now IPv6 users may be unable to connect to IPv4 Web sites.

– In Australia, Adelaide-based ISP Internode yesterday said it had ensured that its customers should have few problems, since for the past year it has been offering them “dual-stack” IPv4 and IPv6 addresses capable of handling both systems.

MD Simon Hackett said Internode is holding sufficient IPv4 addresses to meet demand for the next three to five years, and customers would be under no pressure to migrate.

During 2011, Internode would move an existing national trial IPv6 service through to full production. At this point all new Internode customers would be provided with the dual stack services, and all new routers sold by Internode would enable the use of both versions on a customer’s network.