IPv6 prefix
ff00:0:0:0:0:0:0:0/8
Special-Purpose Address Block: Multicast
- Public routing
- by scope; not ordinary unicast reachability
- IP Prefix (CIDR)
- ff00:0:0:0:0:0:0:0/8
- Address Count
- 1.3292 x 10^36
IPv6 multicast addresses identify a group rather than one host. They are used for neighbor discovery, routing protocols, service discovery, and application multicast.
Reachability depends on multicast scope and network support. This block is not ordinary unicast Internet address space.
A system administrator may see it as destination traffic for local network control and discovery. As a remote source in an Internet-facing log, it usually indicates spoofed input or malformed log data.
Firewall tip: do not treat multicast as a client identity. Apply multicast-specific scope rules and drop it where ordinary unicast traffic is expected.
| Block | Name |
|---|---|
| 0:0:0:0:0:0:0:1/128 | Loopback |
| 0:0:0:0:0:0:0:0/128 | Unspecified Address |
| 0:0:0:0:0:ffff:0:0/96 | IPv4-Mapped Address |
| 64:ff9b:0:0:0:0:0:0/96 | Network Address Translation 64 (NAT64) Well-Known Prefix |
| 64:ff9b:1:0:0:0:0:0/48 | Network Address Translation 64 (NAT64) Local-Use Prefix |
| 100:0:0:0:0:0:0:0/64 | Discard-Only Address Block |
| 100:0:0:1:0:0:0:0/64 | Dummy IPv6 Prefix |
| 2001:0:0:0:0:0:0:0/23 | IETF (Internet Engineering Task Force) Protocol Assignments |
| 2001:0:0:0:0:0:0:0/32 | Teredo |
| 2001:1:0:0:0:0:0:1/128 | Port Control Protocol (PCP) Anycast |
| 2001:1:0:0:0:0:0:2/128 | Traversal Using Relays around NAT (TURN) Anycast |
| 2001:1:0:0:0:0:0:3/128 | DNS-SD Service Registration Protocol Anycast |
| 2001:2:0:0:0:0:0:0/48 | Benchmarking |
| 2001:3:0:0:0:0:0:0/32 | Automatic Multicast Tunneling (AMT) |
| 2001:4:112:0:0:0:0:0/48 | Autonomous System 112 (AS112) Service |
| 2001:10:0:0:0:0:0:0/28 | Deprecated Overlay Routable Cryptographic Hash Identifiers (ORCHID) |
| 2001:20:0:0:0:0:0:0/28 | Overlay Routable Cryptographic Hash Identifiers Version 2 (ORCHIDv2) |
| 2001:30:0:0:0:0:0:0/28 | Drone Remote ID Protocol Entity Tags (DETs) |
| 2001:db8:0:0:0:0:0:0/32 | Documentation (RFC 3849) |
| 2002:0:0:0:0:0:0:0/16 | 6to4 |
| 2620:4f:8000:0:0:0:0:0/48 | Direct Delegation Autonomous System 112 (AS112) Service |
| 3fff:0:0:0:0:0:0:0/20 | Documentation (RFC 9637) |
| 5f00:0:0:0:0:0:0:0/16 | Segment Routing over IPv6 (SRv6) Segment Identifiers |
| fc00:0:0:0:0:0:0:0/7 | Unique Local Address |
| fe80:0:0:0:0:0:0:0/10 | Link-Local Unicast |
| 0:0:0:0:0:0:0:0/8 | Reserved by IETF (Internet Engineering Task Force) |
| 0:0:0:0:0:0:0:0/96 | Deprecated IPv4-Compatible IPv6 Prefix |
| fec0:0:0:0:0:0:0:0/10 | Deprecated Site-Local Unicast |