UniFi switch not initializing: how to fix it

Published onby Iron (edited on )

You're ready to power up your UniFi switch, but it’s stuck. The lights are blinking, the dashboard says "initializing," and you're starting to feel that familiar tech frustration. Don’t worry — you’re not alone.

Let’s get into it.

Table of Contents

Why is my UniFi switch stuck on initializing?

When your UniFi switch won’t move past "initializing," it’s a sign that it’s struggling to communicate with your controller or network. Here are some of the common reasons:

  1. Firmware issues – Outdated or corrupted firmware is a major culprit.
  2. Adoption issues – The controller may not recognize or "adopt" the switch.
  3. IP address conflicts – The switch is fighting for an IP address with another device.
  4. Power issues – A poor or inconsistent power source can cause initialization loops.
  5. Port conflicts – Necessary network ports for communication are being blocked.
  6. Factory reset required – If all else fails, the switch might need a fresh start.

How to troubleshoot a UniFi switch stuck on initializing

Let’s dive into how you can fix it. These steps go from the simplest to the more involved solutions.

1. Check the power source

Your UniFi switch might look powered on, but it may not be receiving enough juice to boot properly.

What to do:

  • Ensure you’re using a compatible power adapter or PoE (Power over Ethernet) switch.
  • Try unplugging the switch and plugging it back in after 10 seconds.
  • If you’re using a PoE switch, try a different port or cable.

Pro Tip: If you’re using a UniFi PoE switch to power another UniFi device, try swapping ports to ensure the issue isn’t related to the specific port.

2. Verify Ethernet connection

UniFi switches need an active network connection to talk to the controller. If the connection is flaky, initialization will stall.

What to do:

  • Check if the Ethernet cable is securely connected to the switch.
  • Test the cable with another device or try using a new cable.
  • Connect the switch directly to your main network (bypass other switches, hubs, etc.).

Pro Tip: Use the UniFi WiFiman app to see if the switch is showing up in your network. If it’s using a fallback IP (like 192.168.1.20), it means it can’t get an IP from your DHCP server.

3. Check the controller

If the switch isn't communicating with the UniFi Controller, it will remain in the "initializing" state.

What to do:

  • Make sure your UniFi Controller is online and accessible.
  • Restart the UniFi Controller service. On UniFi OS devices (like a Cloud Key), go to Settings > Applications > Restart Controller.
  • Verify the UniFi Controller is on the latest version. Update it if necessary.
  • Check if the switch appears under Devices. If it says “Managed by Another Console,” you’ll need to reset it.

Pro Tip: If you’re using a self-hosted controller, make sure the IP address of the controller hasn’t changed. If it has, you’ll need to "set-inform" the switch with the correct IP.

4. Update the firmware

An outdated firmware version could be causing issues, especially if you recently updated the UniFi Controller.

What to do:

  • Log in to the UniFi Controller.
  • Go to Devices, locate the switch, and see if there’s a firmware update available.
  • If the switch is not listed, you'll need to SSH into the device manually to update it.

How to update firmware via SSH:

  1. Find the switch’s IP address using the UniFi app or network scanner (like WiFiman).

  2. SSH into the switch using:
    ssh ubnt@<IP_ADDRESS_OF_SWITCH>
    

    The default username and password are typically ubnt for both.

  3. Run the following command to update the firmware:
    upgrade https://dl.ui.com/path/to/firmware/file.bin
    
  4. Wait for the firmware to install and the switch to reboot.

Pro Tip: Ensure your UniFi switch can access the internet, or use the Advanced Update Cache method if your network blocks direct downloads.

5. Resolve IP address conflicts

If multiple devices are using the same IP address, the switch won’t know how to communicate with the controller.

What to do:

  • Log in to your DHCP server (usually your router) and check for IP conflicts.
  • Reserve an IP for your UniFi switch to prevent future conflicts.

Pro Tip: Set a static IP for your UniFi switch to avoid this issue in the future. This can be done through the UniFi Controller under Devices > Manage > Network.

6. Open required ports

Your network firewall may be blocking key communication ports, causing the switch to get stuck.

What to do:

  • Open the following ports on your firewall/router:
  • TCP/UDP Port 443 (for controller access)
  • TCP Port 8883 (for UniFi OS)
  • UDP Port 10001 (for device discovery)
  • TCP/UDP Port 53 (DNS)
  • UDP Port 123 (NTP)
  • TCP Port 8080 (UniFi inform port)

Pro Tip: For advanced setups, make sure your VLAN rules aren’t blocking traffic from the switch.

7. Factory reset the switch

If none of the above worked, it’s time to reset the switch.

How to do a factory reset:

  1. Find the reset button (usually a small pinhole) on the switch.
  2. Hold it down for 10-15 seconds until the LED flashes.
  3. Wait for the switch to reboot and return to the default state.

Note: A factory reset will remove all previous configurations from the switch, and you’ll need to adopt it back into the controller.

Pro Tip: After the reset, be sure to follow the adoption process properly. If the controller is hosted on the cloud, you may need to use the set-inform command:

set-inform http://<CONTROLLER_IP>:8080/inform

Preventative measures

Once you’ve fixed the issue, here are some steps to prevent it from happening again.

  1. Update regularly – Keep both the UniFi Controller and firmware up-to-date.
  2. Use static IPs – Avoid future IP conflicts by setting static IPs for critical devices.
  3. Back up configurations – Backup your UniFi Controller regularly to avoid reconfiguration headaches.
  4. Use UniHosted – A cloud-hosted UniFi Controller avoids local power or IP issues. Check out UniHosted’s solution here.

When to contact support

If you’ve tried all the steps and the switch is still stuck on initializing, it may be a hardware issue. Contact UniFi support, and they can assist with warranty claims or additional troubleshooting.

Final thoughts

A UniFi switch stuck on "initializing" is annoying, but it's a solvable problem. Usually, a simple reboot or power check will do the trick. If not, follow the steps outlined above, and you’ll have it back in action.

For extra peace of mind, you can use a cloud-hosted controller from UniHosted to avoid these headaches entirely. Our hosted service takes care of firmware updates, backups, and UniFi Controller uptime.

If you would like me to personally walk you through UniHosted, you can schedule a call with me here.

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