The IPv6 address management function was formally delegated to
IANA in December 1995 [RFC1881]. The registration procedure
was confirmed with the IETF Chair in march 2010.
This registry is also available in XML and plain text formats.
| IPv6 Prefix | Allocation | Reference | Note |
|---|---|---|---|
| 0000::/8 | Reserved by IETF | [RFC4291] | [1][5][6] |
| 0100::/8 | Reserved by IETF | [RFC4291] | |
| 0200::/7 | Reserved by IETF | [RFC4048] | [2] |
| 0400::/6 | Reserved by IETF | [RFC4291] | |
| 0800::/5 | Reserved by IETF | [RFC4291] | |
| 1000::/4 | Reserved by IETF | [RFC4291] | |
| 2000::/3 | Global Unicast | [RFC4291] | [3] |
| 4000::/3 | Reserved by IETF | [RFC4291] | |
| 6000::/3 | Reserved by IETF | [RFC4291] | |
| 8000::/3 | Reserved by IETF | [RFC4291] | |
| A000::/3 | Reserved by IETF | [RFC4291] | |
| C000::/3 | Reserved by IETF | [RFC4291] | |
| E000::/4 | Reserved by IETF | [RFC4291] | |
| F000::/5 | Reserved by IETF | [RFC4291] | |
| F800::/6 | Reserved by IETF | [RFC4291] | |
| FC00::/7 | Unique Local Unicast | [RFC4193] | |
| FE00::/9 | Reserved by IETF | [RFC4291] | |
| FE80::/10 | Link Local Unicast | [RFC4291] | |
| FEC0::/10 | Reserved by IETF | [RFC3879] | [4] |
| FF00::/8 | Multicast | [RFC4291] |
| [1] |
The "unspecified address", the "loopback address", and the IPv6 Addresses with Embedded IPv4 Addresses are assigned out of the 0000::/8 address block. |
| [2] |
0200::/7 was previously defined as an OSI NSAP-mapped prefix set [RFC4548]. This definition has been deprecated as of December 2004 [RFC4048]. |
| [3] |
The IPv6 Unicast space encompasses the entire IPv6 address range with the exception of FF00::/8. [RFC4291] IANA unicast address assignments are currently limited to the IPv6 unicast address range of 2000::/3. IANA assignments from this block are registered in the IANA registry: [IANA registry ipv6-unicast-address-assignments]. |
| [4] |
FEC0::/10 was previously defined as a Site-Local scoped address prefix. This definition has been deprecated as of September 2004 [RFC3879]. |
| [5] |
0000::/96 was previously defined as the "IPv4-compatible IPv6 address" prefix. This definition has been deprecated by [RFC4291]. |
| [6] |
The "Well Known Prefix" 64:ff9b::/96 used in an algorithmic mapping between IPv4 to IPv6 addresses is defined out of the 0000::/8 address block, per [RFC-ietf-behave-address-format]. |