UniFi Device Won't Connect? A Troubleshooting Guide
Whether it's a new access point (AP) that won't adopt or an existing camera that has suddenly gone offline, a UniFi device that won't connect can bring your network to a halt. This guide provides a systematic approach to troubleshooting and resolving the most common UniFi connection issues.
Understanding the UniFi Ecosystem
UniFi devices are designed to be 'managed' by a UniFi Network Controller. The device must be able to communicate with this controller over your local network. A connection failure usually means there is a breakdown in this communication path. The process of linking a new device to the controller is called 'adoption'.
Step 1: Physical Layer Checks
Always start with the most basic physical elements: power and cabling.
Verify Power Source
UniFi devices are typically powered via Power over Ethernet (PoE).
- Check the PoE Source: Ensure the PoE switch or PoE injector the device is connected to is powered on and functioning correctly. Try a different port on the switch if possible.
- Inspect the LED Status Light: The LED light on the UniFi device is your best indicator. No light means no power. A solid white light means it's powered on and waiting for adoption. A solid blue light means it's connected and working.
- Use a Different PoE Injector: If you suspect the injector is faulty, test with a known good one.
Inspect Ethernet Cabling
A faulty network cable is a common point of failure.
- Secure Connections: Ensure the Ethernet cable is securely clicked into place at both ends – the device and the switch/injector.
- Test the Cable: The easiest way to rule out a bad cable is to replace it with a new, known-good one. Cable testers are also a valuable tool for network installers.
Step 2: Network and Adoption Troubleshooting
If the device has power and a good cable, the problem lies on the network.
'Adoption Failed' Errors
This is a common issue when setting up new devices.
- Network Subnets: For simple adoption, the UniFi device and the UniFi Network Controller must be on the same network subnet. For example, if your controller's IP is 192.168.1.10, the device should have an IP like 192.168.1.x.
- Firewall Blocking: This is a major cause of adoption failure. The UniFi Controller communicates on specific TCP and UDP ports (notably TCP 8080 for device communication). A firewall on the computer running the controller, or a network firewall, can block this traffic. Temporarily disabling the firewall on the controller machine is a key diagnostic step.
- Controller Accessibility: Can the device 'see' the controller? You can use SSH to access the device and manually set the controller's address using the
set-informcommand. This is an advanced step but is very effective for troubleshooting.
Existing Device Goes 'Offline'
If a previously working device disconnects, the cause is often similar.
- IP Address Change: Did the IP address of your UniFi Controller change? If the controller has a dynamic IP, the device may not be able to find it after a reboot. It's best practice to set a static IP address for your controller.
- Network Changes: Have you recently made any changes to your network, such as adding a new router or switch, or changing VLAN configurations? These changes can disrupt the communication path.
Step 3: Resetting the Device
If all else fails, a factory reset can resolve issues caused by a bad configuration.
How to Factory Reset
- Physical Reset Button: Most UniFi devices have a small, recessed reset button. While the device is powered on, press and hold this button with a paperclip for about 10 seconds, until the LED light changes or flashes.
- Forget in Controller: In the UniFi Network Controller, you can 'Forget' a device. This removes it from the controller and, in most cases, triggers a factory reset on the device itself.
After a reset, the device's LED will turn solid white, indicating it is ready to be adopted again. You can then attempt the setup process from the beginning. By methodically checking the physical, network, and software layers, you can resolve nearly any UniFi connection issue.