| IPv6 address | Prefix length (bits) | Description | Notes |
| :: | 128 | unspecified | Used for default route and router solicitations. cf. 0.0.0.0 in IPv4 |
| ::1 | 128 | loopback address | cf. 127.0.0.1 in IPv4 |
| ::ffff:a.b.c.d | 96 | IPv4 mapped IPv6 address | The lower 32 bits are the IPv4 address. Used in socket API's to represent IPv4 hosts. |
| fe80:: | 10 | link-local | Unroutable autoconfigured addresses used on a LAN, e.g. for DHCPv6 |
| fc00:: | 7 | unique local | Addresses used only within an autonomous system, unroutable globally. Cf. RFC 1918 addresses such as used in NAT. |
| ff00:: | 8 | multicast | |
| 2000:: | 3 | global unicast | All global unicast addresses currently begin with 2. |
Some IPv6 address prefixes have been deprecated, and should no longer be used.
| Deprecated IPv6 address | Prefix length (bits) | Description | Notes |
| 3ffe:: | 16 | 6bone prefix | Used 1998-2006. |
| ::a.b.c.d | 96 | embedded IPv4 | 96 zero bits followed by 32 IPv4 bits. Also called “IPv4 compatible IPv6 address”. Replaced by mapped addresses. |
| fec0:: | 10 | site-local | Replaced by Unique Local Addresses |
Some address prefixes are special use:
| Special IPv6 address | Prefix length (bits) | Description | Notes |
| 2001:db8:: | 32 | documentation examples | Not to be routed. |
| 2001:0:: | 32 | Teredo tunnels | The remaining bits come from a Teredo server and the client NAT device. |
| 2002:: | 16 | 6to4 tunnels | The next 32 bits are the client IPv4 address |