Internet Protocol Version 6 Address Space
- Last Updated
- 2019-09-13
- Note
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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. 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 [RFC3513] was obsoleted by [RFC4291], the guidance provided to IANA did not change regarding the allocation of IPv6 unicast addresses.
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- Registration Procedure(s)
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IESG Approval
- Available Formats
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CSV
IPv6 Prefix | Allocation | Reference | Notes |
---|---|---|---|
0000::/8 | Reserved by IETF | [RFC3513][RFC4291] | [1] [2] [3] [4] [5] [6] |
0100::/8 | Reserved by IETF | [RFC3513][RFC4291] | 0100::/64 reserved for Discard-Only Address Block [RFC6666]. Complete registration details are found in [IANA registry iana-ipv6-special-registry]. |
0200::/7 | Reserved by IETF | [RFC4048] | Deprecated as of December 2004 [RFC4048]. Formerly an OSI NSAP-mapped prefix set [RFC4548]. |
0400::/6 | Reserved by IETF | [RFC3513][RFC4291] | |
0800::/5 | Reserved by IETF | [RFC3513][RFC4291] | |
1000::/4 | Reserved by IETF | [RFC3513][RFC4291] | |
2000::/3 | Global Unicast | [RFC3513][RFC4291] | The IPv6 Unicast space encompasses the entire IPv6 address range with the exception of ff00::/8, per [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 [IANA registry ipv6-unicast-address-assignments]. [7] [8] [9] [10] [11] [12] [13] [14] [15] |
4000::/3 | Reserved by IETF | [RFC3513][RFC4291] | |
6000::/3 | Reserved by IETF | [RFC3513][RFC4291] | |
8000::/3 | Reserved by IETF | [RFC3513][RFC4291] | |
a000::/3 | Reserved by IETF | [RFC3513][RFC4291] | |
c000::/3 | Reserved by IETF | [RFC3513][RFC4291] | |
e000::/4 | Reserved by IETF | [RFC3513][RFC4291] | |
f000::/5 | Reserved by IETF | [RFC3513][RFC4291] | |
f800::/6 | Reserved by IETF | [RFC3513][RFC4291] | |
fc00::/7 | Unique Local Unicast | [RFC4193] | For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
fe00::/9 | Reserved by IETF | [RFC3513][RFC4291] | |
fe80::/10 | Link-Scoped Unicast | [RFC3513][RFC4291] | Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv6-special-registry]. |
fec0::/10 | Reserved by IETF | [RFC3879] | Deprecated by [RFC3879] in September 2004. Formerly a Site-Local scoped address prefix. |
ff00::/8 | Multicast | [RFC3513][RFC4291] | IANA assignments from this block are registered in [IANA registry ipv6-multicast-addresses]. |
Footnotes
[1] |
::1/128 reserved for Loopback Address [RFC4291]. Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv6-special-registry]. |
[2] |
::/128 reserved for Unspecified Address [RFC4291]. Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv6-special-registry]. |
[3] |
::ffff:0:0/96 reserved for IPv4-mapped Address [RFC4291]. Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv6-special-registry]. |
[4] |
0::/96 deprecated by [RFC4291]. Formerly defined as the "IPv4-compatible IPv6 address" prefix. |
[5] |
The "Well Known Prefix" 64:ff9b::/96 is used in an algorithmic mapping between IPv4 to IPv6 addresses [RFC6052]. |
[6] |
64:ff9b:1::/48 reserved for Local-Use IPv4/IPv6 Translation [RFC8215]. |
[7] |
2001:0::/23 reserved for IETF Protocol Assignments [RFC2928]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
[8] |
2001:0::/32 reserved for TEREDO [RFC4380]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
[9] |
2001:2::/48 reserved for Benchmarking [RFC5180][RFC Errata 1752]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
[10] |
2001:3::/32 reserved for AMT [RFC7450]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
[11] |
2001:4:112::/48 reserved for AS112-v6 [RFC7535]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
[12] |
2001:10::/28 deprecated (formerly ORCHID) [RFC4843]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
[13] |
2001:20::/28 reserved for ORCHIDv2 [RFC7343]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
[14] |
2001:db8::/32 reserved for Documentation [RFC3849]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |
[15] |
2002::/16 reserved for 6to4 [RFC3056]. For complete registration details, see [IANA registry iana-ipv6-special-registry]. |