The type of an IPv6 address is identified by the high-order bits of the address, as follows.
|
Address Type |
Binary Prefix |
IPv6 Notation |
|---|---|---|
|
unspecified |
00...0 (128 bits) |
::/128 |
|
loopback |
00...1 (128 bits) |
::1/128 |
|
multicast |
11111111 |
FF00::/8 |
|
link-local unicast |
1111111010 |
FE80::/10 |
|
global unicast |
(everything else) |
Anycast addresses are taken from the unicast address spaces (of any scope) and are not syntactically distinguishable from unicast addresses.
The general format of global unicast addresses is described in Global Unicast Addresses later in this section. Future specifications might redefine one or more subranges of the global unicast space for other purposes, but for now, implementations must treat all addresses that do not start with any of the previously listed prefixes as global unicast addresses.
