IPv6 prefix
2002:0:0:0:0:0:0:0/16
- Public routing
- not applicable; transition behavior depends on context
- IP Prefix (CIDR)
- 2002:0:0:0:0:0:0:0/16
- Address Count
- 5.1923 x 10^33
6to4 is an older IPv6 transition mechanism that embeds an IPv4 address inside an IPv6 prefix.
IANA marks global reachability as not applicable for this row. It is transition space rather than ordinary native IPv6 allocation.
A system administrator may see it in old tunnel traffic, legacy examples, or logs from networks that still expose 6to4-derived addresses.
Firewall tip: treat it as legacy transition context. If 6to4 is not intentionally supported, avoid allowing it as normal client traffic.
| 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) |
| 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 |
| ff00:0:0:0:0:0:0:0/8 | Multicast |
| Announced Prefix | Relationship | Origin ASN | Description | Country | First Address | Last Address |
|---|---|---|---|---|---|---|
| 2002:0:0:0:0:0:0:0/16 | Exact | AS6939 | Hurricane Electric LLC |
United States of America (US)
|
2002:0:0:0:0:0:0:0 | 2002:ffff:ffff:ffff:ffff:ffff:ffff:ffff |
| 2002:0:0:0:0:0:0:0/16 | Exact | AS7725 | Comcast Cable Communications LLC |
United States of America (US)
|
2002:0:0:0:0:0:0:0 | 2002:ffff:ffff:ffff:ffff:ffff:ffff:ffff |