Internet Protocol version 6 (IPv6) is an Internet Layer protocol for packet-switched internetworks. The Internet Engineering Task Force (IETF) has designated IPv6 as the successor of IPv4, the first and still dominant version of the Internet Protocol, for general use on the Internet.
IPv6 has a much larger address space than IPv4, which allows flexibility in allocating addresses and routing traffic. The extended address length eliminates the need to use network address translation to avoid address exhaustion, and also simplifies aspects of address assignment and renumbering when changing Internet connectivity providers.
The very large IPv6 address space supports 2128 (about 3.4×038) addresses, or approximately 5×028 (roughly 295) addresses for each of the roughly 6.5 billion (6.5×09) people alive today.[1] In a different perspective, this is 252 addresses for every observable star in the known universe[2] . more than ten billion billion billion times as many addresses as IPv4 supported.
While these numbers are impressive, it was not the intent of the designers of the IPv6 address space to assure geographical saturation with usable addresses. Rather, the large number allows a better, systematic, hierarchical allocation of addresses and efficient route aggregation. With IPv4, complex Classless Inter-Domain Routing (CIDR) techniques were developed to make the best use of the small address space. Renumbering an existing network for a new connectivity provider with different routing prefixes is a major effort with IPv4, as discussed in RFC 2071 and RFC 2072. With IPv6, however, changing the prefix in a few routers can renumber an entire network ad hoc, because the host identifiers (the least-significant 64 bits of an address) are decoupled from the subnet identifiers and the network provider's routing prefix. The size of each subnet in IPv6 is 264 addresses (64 bits); the square of the size of the entire IPv4 Internet. Thus, actual address space utilization rates will likely be small in IPv6, but network management and routing will be more efficient.
Tele2 has, in some degree, been IPv6 enabled since the beginning of 2002. In late 2007, the decision to implement IPv6 natively and alongside IPv4 in the network, was taken. Mid-2008 this was to a large extent complete and virtually all core nodes of Tele2s pan-european network are now IPv6 enabled. Some 90% (a number bound to fluctuate) of the IPv6 prefixes on the Internet can be reached via Tele2s customers or peers leaving Tele2 a very well connected network.
It is the goal and vision of Tele2 to stay at this technological forefront, implementing new technologies and facilitating for the widespread deployment of IPv6 across the Internet in any way we can..