169.254.0.0/16
Link-Local RFC 3927169.254.0.0/16 is the link-local address range. Hosts automatically assign themselves an address in this range when DHCP fails (Windows calls this APIPA). Cloud providers also use 169.254.169.254 as the instance metadata service endpoint.
Network address — the base address of the block (169.254.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.
Broadcast address — packets sent to 169.254.255.255 are delivered to every device in the subnet. Also reserved — not assignable.
Usable hosts — the 65,534 addresses between those two that you can assign to servers, VMs, or interfaces.
Subnet mask — 255.255.0.0 is the dotted-decimal equivalent of /16. Older tools and Cisco configs use this format instead of CIDR slash notation.
Full Details
| CIDR Notation | 169.254.0.0/16 |
| Network Address | 169.254.0.0 |
| Broadcast Address | 169.254.255.255 |
| Subnet Mask | 255.255.0.0 |
| Wildcard Mask | 0.0.255.255 |
| Prefix Length | /16 |
| IP Address Class | Class B |
| Total IP Addresses | 65,536 |
| Usable Host Addresses | 65,534 |
| First Usable IP | 169.254.0.1 |
| Last Usable IP | 169.254.255.254 |
| Network (Hex) | 0xA9FE0000 |
| Broadcast (Hex) | 0xA9FEFFFF |
| Governing RFC | RFC 3927 |
| Address Type | Link-Local (APIPA) |
Binary Representation
The first 16 bits (1s in the mask) identify the network. The remaining 16 bits identify hosts within the network.
Subnet Breakdown — splitting into /17
This /16 block can be divided into 2 /17 subnets.
| CIDR | Network | Broadcast | First Usable | Last Usable | Hosts |
|---|---|---|---|---|---|
| 169.254.0.0/17 | 169.254.0.0 | 169.254.127.255 | 169.254.0.1 | 169.254.127.254 | 32,766 |
| 169.254.128.0/17 | 169.254.128.0 | 169.254.255.255 | 169.254.128.1 | 169.254.255.254 | 32,766 |
Common Use Cases
- → Automatic Private IP Addressing (APIPA) on Windows
- → AWS instance metadata service (169.254.169.254)
- → Azure IMDS endpoint (169.254.169.254)
- → mDNS and Bonjour service discovery