2019-09-13 The IPv6 address management function was formally delegated to IANA in December 1995 . The registration procedure was confirmed with the IETF Chair in March 2010. As stated in RFC3513, IANA should limit its allocation of IPv6-unicast address space to the range of addresses that start with binary value 001. The rest of the global unicast address space (approximately 85% of the IPv6 address space) is reserved for future definition and use, and is not to be assigned by IANA at this time. While was obsoleted by , the guidiance provided to IANA did not change regarding the allocation of IPv6 unicast addresses. IESG Approval 0000::/8 Reserved by IETF 0100::/8 Reserved by IETF 0100::/64 reserved for Discard-Only Address Block . Complete registration details are found in . 0200::/7 Reserved by IETF Deprecated as of December 2004 . Formerly an OSI NSAP-mapped prefix set . 0400::/6 Reserved by IETF 0800::/5 Reserved by IETF 1000::/4 Reserved by IETF 2000::/3 Global Unicast The IPv6 Unicast space encompasses the entire IPv6 address range with the exception of ff00::/8, per . IANA unicast address assignments are currently limited to the IPv6 unicast address range of 2000::/3. IANA assignments from this block are registered in . 4000::/3 Reserved by IETF 6000::/3 Reserved by IETF 8000::/3 Reserved by IETF a000::/3 Reserved by IETF c000::/3 Reserved by IETF e000::/4 Reserved by IETF f000::/5 Reserved by IETF f800::/6 Reserved by IETF fc00::/7 Unique Local Unicast For complete registration details, see . fe00::/9 Reserved by IETF fe80::/10 Link-Scoped Unicast Reserved by protocol. For authoritative registration, see . fec0::/10 Reserved by IETF Deprecated by in September 2004. Formerly a Site-Local scoped address prefix. ff00::/8 Multicast IANA assignments from this block are registered in . ::1/128 reserved for Loopback Address . Reserved by protocol. For authoritative registration, see . ::/128 reserved for Unspecified Address . Reserved by protocol. For authoritative registration, see . ::ffff:0:0/96 reserved for IPv4-mapped Address . Reserved by protocol. For authoritative registration, see . 0::/96 deprecated by . Formerly defined as the "IPv4-compatible IPv6 address" prefix. The "Well Known Prefix" 64:ff9b::/96 is used in an algorithmic mapping between IPv4 to IPv6 addresses . 64:ff9b:1::/48 reserved for Local-Use IPv4/IPv6 Translation . 2001:0::/23 reserved for IETF Protocol Assignments . For complete registration details, see . 2001:0::/32 reserved for TEREDO . For complete registration details, see . 2001:2::/48 reserved for Benchmarking . For complete registration details, see . 2001:3::/32 reserved for AMT . For complete registration details, see . 2001:4:112::/48 reserved for AS112-v6 . For complete registration details, see . 2001:10::/28 deprecated (formerly ORCHID) . For complete registration details, see . 2001:20::/28 reserved for ORCHIDv2 . For complete registration details, see . 2001:db8::/32 reserved for Documentation . For complete registration details, see . 2002::/16 reserved for 6to4 . For complete registration details, see .