IPv6 prefix

100:0:0:0:0:0:0:0/64

Special-Purpose Address Block: Discard-Only Address Block
Public routing
not expected to be globally reachable
IP Prefix (CIDR)
100:0:0:0:0:0:0:0/64
Address Count
1.8447 x 10^19

This block is reserved for discard-only routing. Operators can route traffic to it when they intentionally want packets to be dropped.

This block is not expected to be globally reachable as a service destination.

A system administrator may encounter it in blackhole routes, filter tests, or traffic-engineering examples where the goal is controlled discard behavior.

Firewall tip: traffic to or from this block should normally be treated as discard, test, or route-filtering context rather than user 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
100:0:0:1:0:0:0:0/64 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
ff00:0:0:0:0:0:0:0/8 Multicast