Link-local address
169.254.169.254
169.254.169.254 is in 169.254.0.0/16, the link-local block (RFC 3927). It isn't routed on the public internet, so there's nothing public to look up. The instance metadata service in AWS, Google Cloud, Azure and other clouds: a virtual machine asks it for its identity, settings and temporary credentials. It only answers from inside the machine.
At a glance
- Block
- 169.254.0.0/16
- Defined in
- RFC 3927
- On the public internet
- No
About this block
A device that can't get an address from a DHCP server picks one from 169.254.0.0/16 by itself. It can then talk to other devices on the same cable or Wi-Fi network, but nothing past the router.
In IPv6, every interface always has a link-local address in fe80::/10 alongside its others. Routers advertise themselves from theirs, so IPv6 default gateways are often fe80:: addresses.
Where you'll see it
- A 169.254 address on your computer, which usually means it couldn't reach the router's DHCP server.
- 169.254.169.254, the metadata service inside AWS, Google Cloud, Azure and other clouds.
- IPv6 gateways and neighbors in ip route or netstat output, shown as fe80:: addresses with a %interface suffix.