If you’ve been around computers long enough, you know an IP address that starts with 169.254 usually means trouble. But what is a 169 IP address, what does it mean, and how do you fix it?
A 169.254 IP address is called an APIPA IP address. Your computer receives a 169 APIPA address when it can’t get an address from the DHCP server.
What does a 169 IP address mean?
When your computer gets an IP address starting in 169.254, it means it couldn’t reach the DHCP server to get a real IP address. Several conditions can cause this situation. If this happens at home, it could mean the wireless connection in either your laptop or your router stopped working. If you have a wired connection, it can mean your cable is bad or is unplugged on one end or the other, or it could mean the wired interface on either side of the connection isn’t working.
In the workplace, a 169 IP address usually means the cable isn’t plugged into one or more wired network interfaces. I see them all the time on servers that have multiple network cards, and one or more of the cards isn’t in use. Asset management systems and vulnerability scanners can pick up these addresses while inventorying systems. But if these addresses show up in your network inventory, you can safely ignore them. And you should.
In a job interview, an interviewer may ask if a 169.254 address is publicly routable. It is not.
What is a 169 IP address called?
A 169.254 IP address is called an APIPA address. APIPA means Automatic IP Addressing. Windows Vista and newer versions will grab an APIPA address if they can’t get a response from a DHCP server within six seconds. But it will keep trying, and if a DHCP server responds, then it will use a proper IP address. The built-in Windows utility IPCONFIG calls these an autoconfiguration IP address.
These APIPA addresses aren’t terribly useful, since the only things they can communicate with, assuming they’re actually on a network at all, are other devices that also have an APIPA address. A system in this state won’t have Internet access.
How to fix a 169 IP address
If your system has a 169 IP address, it’s usually possible to fix it.
Opening a command prompt and typing the command ipconfig /release followed by ipconfig /renew can be helpful. It will tell you if Windows thinks your network card is connected. If your wireless connection is disconnected, try reconnecting. Make sure your usual SSID shows up in the list. If it doesn’t, reboot your router, which is a good thing to do from time to time anyway. If no SSIDs show up in the list, make sure your wireless network card is working. Some laptops have a switch or button that turns your wireless connection on or off. If the wireless card is on but still not working, try restarting your system.
If you have a wired connection and Windows thinks it’s not connected, try unplugging the cable and plugging it back in on both sides. And if that doesn’t work, try changing cables. It’s a little unusual for network cables to go bad, but they can. I’ve fixed a lot of persistent issues by swapping out a cable. It’s also not a bad idea to try a different port on your switch or router.
Most of the time, restarting some combination of the computer, switch, or router and/or changing the network cable will fix this issue.
Troubleshooting 169 APIPA addresses without ipconfig
If you’re unable to use ipconfig, you can still troubleshoot this issue. You just may not get quite as much feedback from the system, but the steps are mostly the same.
Switching from a wireless connection to a wired connection is a good first troubleshooting step. It establishes whether your network equipment is functioning. If that works, try reconnecting to your wireless. Make sure your usual SSID is showing up in the list of available networks, then try disconnecting and reconnecting.
If you are unable to connect or your SSID isn’t showing up, try rebooting your router. This will usually bring your network connection back to life. Rebooting your device isn’t a bad idea either, just in case the problem is your device’s wireless connection.
If both your wired and wireless connections pull a 169.254 APIPA address, it means your DHCP server is down. Most consumer routers have a built-in DHCP server. Restarting the router will typically restore DHCP functionality.
One way I sidestep this issue on my home network is by assigning IP addresses outside my DHCP range to my printer and my non-portable systems like a desktop PC. This eliminates that point of failure, and when a laptop misbehaves, it helps me pinpoint the problem more quickly.