IPv6 Addresses
Global Unicast Addresses

Global Unicast addresses identify their users on the Internet. They are globally unique addresses that can be recognized by the first three bits in the prefix. RFC 3487 defines the format of Global Unicast addresses. Global Unicast addresses have the following format:

Global Unicast IPv6 Address Format

Description of individual fields of Global Unicast address:

Example of Global Unicast IPv6 Address

Global Unicast addresses are aggregable. It means that the addresses are clustered into groups according to distance from which we look at them. The aggregation of addresses significantly reduces the number of entries in routing tables, which affects the speed of forwarding on the core routers. The fineness classification of routing information decreases with increasing distance. It means that the datagram is forwarded according to the initial bits of destination address (prefix) in the first stage and the examination of destination address becomes more accurate closer to the target node. It is called Hierarchical routing.