IPv6 (global unicast address)

IPv6 (global unicast address)

The effective range (scope) of IPv6 address unicast is classified as follows.

  • global unicast address
  • Site-local unicast address (deprecated)
  • link-local unicast address

Global unicast addresses are described here.

 A global unicast address is defined as a globally unique unicast address, equivalent to the IPv4 global address. The first 3 bits start with '001' and the valid range can also be written as '2000::/3'.


The structure of a global unicast address is as follows.

Within the address range, further usage is determined as follows:

2001::/16IPv6 InternetCurrently, IANA has assigned 2001::/16 as a global unicast address. When building a network with IPv6, addressing will be performed from the address range of 2001::/16.
2002::/166to4 transition mechanismA special address used in a 6to4 tunnel when transitioning from IPv4 to IPv6.
2003::/16~3ffd::/16unassignedIt is currently unassigned, but can be assigned to a router interface.
3ffe::/166boneFor research and development of IPv6