Unifi Base Station Not Connecting? A Troubleshooting Guide

Troubleshooting a Unifi Base Station That Won't Connect

A Unifi network is known for its power and reliability, but when a base station or Access Point (AP) fails to connect, it can bring your wireless network to a standstill. This guide provides a systematic approach to diagnosing and resolving the most common connectivity issues with Unifi APs, helping you get your network back online quickly.

Whether your base station is failing to power on, not appearing in the Unifi Network Controller, or getting stuck in an adoption loop, we will cover the essential checks and solutions.

Common Symptoms of a Connection Problem

Before diving into solutions, it's important to identify the specific symptom your base station is exhibiting:

• No LED Light: The device shows no signs of power.
• Solid White LED: The device is at factory defaults but is not being adopted.
• Flashing White and Blue LED: The device is booting up or trying to establish a connection.
• "Adoption Failed" Error: The Unifi Network Controller sees the device but cannot configure it.
• "Disconnected" Status: The AP was previously working but has now lost its connection to the controller.
• Device Not Appearing in Controller: The controller does not detect the base station on the network at all.

Step-by-Step Troubleshooting Guide

Work through these steps in order to diagnose the root cause of the connection failure.

Step 1: Check Power and Physical Connections

The foundation of any network device is its physical connection. Don't overlook the basics.

1. Verify Power Source: Most Unifi APs use Power over Ethernet (PoE). Confirm that the PoE switch or injector is powered on and functioning. If using an injector, ensure it's the correct voltage for your AP model.
2. Inspect Ethernet Cables: A faulty or poorly seated Ethernet cable is a frequent culprit. Unplug and securely reconnect the cable at both the AP and the switch/injector port.
3. Test with a New Cable: If possible, swap the existing cable with a known good, pre-made Ethernet cable. Cable testers can also be used to verify the integrity of an installed cable run.
4. Try a Different Switch Port: Connect the AP to a different port on your PoE switch to rule out a faulty port.

Step 2: Investigate Network and Controller Settings

If the device has power but still won't connect, the issue likely lies within your network configuration.

1. Confirm Network Segment: The Unifi AP and the Unifi Network Controller must be on the same Layer 2 network (or have a Layer 3 adoption method configured). Ensure the AP is receiving a valid IP address from your DHCP server. You can check your DHCP server's lease table to see if the AP is listed.
2. Check Firewall Rules: Firewalls on your controller's host machine or your network router can block the communication ports required for adoption. Ensure that port TCP 8080 (for device command and control) and UDP 3478 (for STUN) are open and not being blocked.
3. Disable Competing Controller Services: Ensure you do not have another instance of the Unifi Network Controller running on the same network, as this can cause conflicts where the AP tries to connect to the wrong controller.

Step 3: Address Adoption and Provisioning Failures

If the AP is visible in the controller but fails to adopt or stay connected, try these steps.

1. Forget the Device: In the Unifi Network Controller, go to the device's properties and select "Forget this device". This will remove its previous configuration attempt and allow you to start fresh.
2. Perform a Factory Reset: A device stuck in a bad state often needs a full reset.
   • With the AP powered on, press and hold the physical reset button (usually located near the Ethernet port) for more than 10 seconds.
   • The LED will flash, and the device will reboot.
   • Once it settles on a solid white LED, it is ready to be adopted again.
3. Check DNS Resolution: Ensure that the AP can resolve the hostname unifi to the IP address of your Unifi Network Controller. This is a common requirement for seamless adoption, especially in larger networks. You may need to configure a DNS entry on your local DNS server.

By systematically working through these physical, network, and software-related checks, you can identify and resolve the vast majority of connection issues with your Unifi base station.