Why Is My IP 169.254.x.x? APIPA and Self-Assigned Addresses

Your internet is down, you check your network settings, and the IP address reads 169.254.something — an address you never configured, on no network you recognise. That's APIPA (Automatic Private IP Addressing), and it's less an address than a distress signal: "I asked for an IP and nobody answered."

What happened

When a device joins a network, it requests an address via DHCP. If no DHCP server responds, the device — rather than sitting addressless — assigns itself a random address from the reserved 169.254.0.0/16 range (Apple calls this "self-assigned"). It checks via ARP that nobody else picked the same number, and settles in.

The catch: this link-local address only works for talking to other devices on the same cable or Wi-Fi segment. There's no gateway, so there's no internet — which is exactly the symptom that made you look.

Why DHCP didn't answer

• Router is down or rebooting — the most common cause.
• The link is bad — loose Ethernet cable, failing switch port, or Wi-Fi that authenticated but passes no traffic.
• DHCP pool exhausted — every address leased out, latecomers get nothing.
• DHCP disabled — someone turned it off, often while adding a second router.
• Security software interference — overzealous firewalls occasionally block DHCP packets.

The fix ladder

1. Restart the router, wait for it to fully boot, then reconnect. Fixes the majority of cases.
2. Renew the lease — Windows: ipconfig /release + ipconfig /renew; Mac: Renew DHCP Lease in Network settings; phones: forget and rejoin the network.
3. Swap the cable / try another port for wired connections.
4. Check if others are affected — everyone down points at the router; just you points at your device.
5. Verify DHCP is enabled in the router and its pool is big enough.
6. Check for an IP conflict or, rarely, reinstall the network adapter driver.

The one legitimate use

Link-local addressing is genuinely useful in one scenario: two devices cabled directly together with no router — say, a laptop and a bench instrument — both self-assign 169.254 addresses and can communicate. If you weren't doing that on purpose, though, a 169.254 address always means "fix my DHCP."

Frequently asked questions