IPv6 is about to arrive -- and with it many opportunities

The arrival of IPv6 will give agencies better security, more flexible networking, and a very large number of available IP addresses. In a detailed GCN discussion, William jackson says that how well agencies take advantage of IPv6 will depend in large part on how well administrators manage their newfound wealth of IP address spaces, experts say. By the end of June, the Office of Management and Budget (OMB) expects agencies to have their network backbones ready to carry IPv6 traffic in addition to IPv4 traffic. Nobody is yet requiring that agencies use IPv6, but agencies have begun acquiring address space in the new protocols and are making plans for taking advantage of the improved security and networking capabilities.

Management, writes Jackson, will be critical. “It is going to be a long cycle for people to swap out the IPv4 technology” now standard in their networks, said Richard Hyatt, chief technology officer at BlueCat Networks. “It is going to be the management of the address space that determines how quickly it happens.” Management can be a challenge because IPv6 addresses are larger than IPv4 addresses and there are exponentially more of them. As IPv4 addresses start running short, the abundance of new addresses will be a good thing. Administrators, however, will have to resist the temptation to use the new addresses the same way they have used the current generation, said Chip Popoviciu, IPv6 address management expert at Cisco Systems. “We need to be mindful that this is a large resource, and we need to manage it properly,” Popoviciu said. How large a resource are we talking about? “With IPv6, one subnet is as large as the entire Internet is today,” said Sean Siler, Microsoft’s IPv6 program manager. Each agency will have tens of thousands of subnets. “It’s a huge shift in paradigm.”

The large number of addresses is because IPv6 addresses are 128 bits long. The last 64 bits are used to assign the address to a particular device or function rather than a network, but the networking portion still is large enough to provide an almost inexhaustible supply of numbers. Address groups are described in terms of a slash-number, written as “/number.” The smaller the slash-number, the larger the group of addresses. “The general size of an address allocation is a /48,” said Richard Jimmerson, chief information officer at the American Registry for Internet Numbers (ARIN). That size allocation includes 65,536 /64 subnets. A /32 address allocation would contain 4 billion subnets.

There is much more to IPv6, and Jackson’s discussion[/url] offers many useful insights.