A recent study by RIPE (the European Internet Registry for IP addresses) has warned that by 2011 the current version of IP addresses (IPv4) will be depleted, thus it urged all professional bodies and organizations dealing with the Internet to actively adopt and support the new IPv6 address version.
IPv6 addresses are 128 bits long-much longer than the current 32-bit IPv4 address. As we know, the 32-bit IPv4 address scheme supports around 4 billion IP addresses. The new IPv6 version, will support 2 to the 128th power of IP addresses, which is a number that even mathematicians will have a hard time to count!!
The IPv6 address version was designed by the IETF (Internet Engineering Task Force) not only to expand the available address space, but to also incorporate support for new features such as IPSEC security and easier network management through autoconfiguration.
The IPv4 address format was represented as 4 decimal octets in the form of AAA.BBB.CCC.DDD (for example 192.168.100.15). The IPv6 address format is totally different and can be written in the following ways:
In full hexadecimal format, the address is written as eight groups of four hexadecimal digits, with colons separating the groups. For example,
1111:2222:3333:4444:5555:6666:7777:8888 represents a single IPv6 host.
• Leading 0s can be omitted in any group. For example,
1111:0200:0030:0004:5555:6666:7777:8888 can also be written as
• Because IPv6 addresses are so long and the address space is so large, addresses with many embedded 0s are common. Therefore, you can abbreviate any number of contiguous 0s as a double colon (::), even if the 0s cross a digit group boundary. For example, 1111:0:0:0:0:0:0:8888 could also be written as 1111::8888. This abbreviation can be used only once in an address, however.
• IPv6 addresses can also be shown with a network prefix. This specifies how many most significant bits are used to represent a network address. This is very similar to IPv4 addresses, where the address and prefix values are separated by a slash (/). For IPv6, this format is also ipv6_address/prefix_length, where the prefix length is a value from 1 to 128 bits.