IPv4 prefix
192.0.0.170/32
Special-Purpose Address Block: NAT64/DNS64 Discovery
- Public routing
- not expected to be globally reachable
- IP Prefix (CIDR)
- 192.0.0.170/32
- Subnet Mask
- 255.255.255.255
This address is reserved for the standards-defined procedure that discovers a network's NAT64 translation prefix through DNS64.
This address is neither an ordinary source nor a reachable public destination. IP implementations reserve it for the discovery procedure.
A system administrator may see it in DNS responses for ipv4only.arpa, NAT64 diagnostics, packet captures, or transition-network tests.
Firewall tip: do not treat it as a client identity or general-purpose endpoint. Permit only the narrow discovery behavior expected by the NAT64 design.
| Block | Name |
|---|---|
| 0.0.0.0/8 | "This" Network |
| 0.0.0.0/32 | "This Host on This Network" |
| 10.0.0.0/8 | Private Use (RFC 1918) |
| 100.64.0.0/10 | Shared Address Space - CGN (Carrier-Grade Network Address Translation) |
| 127.0.0.0/8 | Loopback |
| 169.254.0.0/16 | Link-Local |
| 172.16.0.0/12 | Private Use (RFC 1918) |
| 192.0.2.0/24 | Documentation (TEST-NET-1) |
| 192.0.0.0/24 | IETF (Internet Engineering Task Force) Protocol Assignments |
| 192.0.0.0/29 | IPv4 Service Continuity Prefix |
| 192.0.0.8/32 | IPv4 Dummy Address |
| 192.0.0.9/32 | Port Control Protocol (PCP) Anycast |
| 192.0.0.10/32 | Traversal Using Relays around NAT (TURN) Anycast |
| 192.0.0.171/32 | NAT64/DNS64 Discovery |
| 192.31.196.0/24 | Autonomous System 112 (AS112) Service |
| 192.52.193.0/24 | Automatic Multicast Tunneling (AMT) |
| 192.88.99.0/24 | Deprecated 6to4 Relay Anycast |
| 192.88.99.2/32 | 6a44 Relay Anycast Address |
| 192.168.0.0/16 | Private Use (RFC 1918) |
| 192.175.48.0/24 | Direct Delegation Autonomous System 112 (AS112) Service |
| 198.18.0.0/15 | Benchmarking |
| 198.51.100.0/24 | Documentation (TEST-NET-2) |
| 203.0.113.0/24 | Documentation (TEST-NET-3) |
| 224.0.0.0/4 | Multicast |
| 240.0.0.0/4 | Reserved |
| 255.255.255.255/32 | Limited Broadcast |