What is IPv6?

Find out why Internet Protocol version 6 (IPv6) is replacing Internet Protocol version 4 (IPv4) as the Internet standard, and how you can use it to your advantage.

IPv6 is the next evolution in Internet Protocol. Most of the Internet uses IPv4, and this protocol has been reliable and resilient for over 20 years. However, IPv4 has limitations that might cause problems as the Internet expands.

In particular, there is a growing shortage of IPv4 addresses, which are needed for all new devices added to the Internet. The key to IPv6 enhancement is the expansion of the IP address space from 32 bits to 128 bits, enabling virtually unlimited, unique IP addresses. The new IPv6 address text format is:

xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx

where each x is a hexadecimal digit representing 4 bits.

The expanded addressing capability of IPv6 provides a solution to the address depletion problem. This is especially important as more people use mobile computers, such as mobile telephones and handheld computers. The increasing demands of wireless users contribute to the depletion of IPv4 addresses. The expanded IP address capability of IPv6 provides enough IP addresses for the growing number of wireless devices.

In addition to this addressing capability, IPv6 provides new functions that simplify the tasks of configuring and managing the addresses on the network. Configuring and maintaining networks is a labor-intensive activity. IPv6 reduces some of the workload by automating several of the network administrator's tasks.

Start of change If you use IPv6, you do not have to renumber your device addresses when you change to a different Internet service provider (ISP). Site renumbering is an important architectural element of IPv6, and is largely automatic. The lower half of your IPv6 address will remain unchanged, because this is traditionally the MAC address of your Ethernet adapter. A new IPv6 prefix will be assigned to you by the ISP, and this new prefix can be distributed to all of the end hosts by updating the IPv6 routers in the network and allowing IPv6 stateless autoconfiguration to "re-learn" the new prefix. End of change

Start of change The IPv6 autoconfiguration feature automatically configures interface addresses and default routes for you. In stateless autoconfiguration, IPv6 takes the MAC address of the machine and a network prefix provided by a local router and combines these two addresses to create a new, unique IPv6 address. This feature eliminates the need for a Dynamic Host Configuration Protocol (DHCP) server. End of change