Internet Protocol version four, or IPv4, is a system of addresses used to identify devices on a network. Originally described in 1981 in RFC791, IPv4 is the most widely used Internet layer protocol, and at this point is used by the vast majority of users to connect to the Internet.

IPv4 addresses are actually 32-bit numbers. This means that there are 232, or just over four billion, possible addresses. Over time, however, it has become clear that more addresses than this will be required to ensure ongoing growth of the Internet. The unused pool of IPv4 addresses is predicted run out in the next two years, so an alternative is required.

IPv4 Exhaustion

On 3 February 2011, the IANA allocated the final five /8s of IPv4 address space to the five Regional Internet Registries (RIRs). The Number Resource Organization (NRO), representing the five RIRs, issued the following statement:

What is IPv6?

Internet Protocol version six, or IPv6, is an Internet layer protocol developed in the 1990s (and described in RFC2460) as an alternative to IPv4. Rather than using a 32-bit system, IPv6 is based on 128-bit addresses, meaning that there are 2128 individual addresses available, which is approximately 3.4×1038, and exactly:

340,282,366,920,938,463,463,374,607,431,768,211,456

IPv6 provides enough addresses to allow the Internet to continue to expand and the industry to innovate. It is not, however, directly compatible with IPv4, meaning that a device connected via IPv4 cannot communicate directly with a device connected using IPv6.

Deploying IPv6 on a global scale is vital to the Internet industry, but it requires pro-active steps on the part of industry players: technology must be upgraded, staff trained, business plans developed. Uptake to date has been relatively slow, but this is now changing, and businesses need to be aware of the need to adopt IPv6. To ignore IPv6 is to risk your medium to long term business viability.