How to Fix IP Conflicts After a UniFi Upgrade
Published onby Iron
Upgrading your UniFi system is supposed to make things better. But every now and then, a pesky IP conflict decides to crash the party. If you’re seeing "IP conflict detected" warnings in your UniFi controller, or some of your devices are randomly disconnecting, you’re in the right place.
Let's dive in!

Table of Contents
- What is an IP conflict?
- Why do IP conflicts happen after a UniFi upgrade?
- How to fix IP conflicts after a UniFi upgrade
- 1. Reboot everything (simple but powerful)
- 2. Clear DHCP leases
- 3. Assign static IPs to important devices
- 4. Use the "Forget" option in the UniFi controller
- 5. Check for duplicate IPs on your network
- 6. Update firmware and UniFi OS
- 7. Factory reset stubborn devices
- 8. Bonus Tip: Improve DNS Settings
- How to avoid IP conflicts in future upgrades
- Frequently Asked Questions
- Final thoughts
What is an IP conflict?
Every device on your network — phones, laptops, smart TVs, printers, even your fridge (yes, smart fridges) — needs its own unique IP address. It’s like having a unique phone number for each device. If two devices have the same IP address, they’ll be constantly fighting for network attention. This is known as an IP conflict.
How do you know there’s an IP conflict?
- Your devices keep disconnecting and reconnecting.
- The UniFi controller shows "IP conflict detected" errors.
- Some devices appear as "Disconnected" in the UniFi controller.
- Devices complain about "Limited Connectivity" on Windows or "No Internet" on smartphones.
After a UniFi upgrade, IP conflicts are more likely to happen due to DHCP changes, new features, or network resets.
Why do IP conflicts happen after a UniFi upgrade?
Here are the top reasons why IP conflicts pop up after an upgrade:
- DHCP lease reset: During an upgrade, the DHCP server might reset or lose track of which devices had which IP addresses.
- IP address reassignments: UniFi might shuffle IP addresses to "clean up" the network, but some devices cling to their old IPs.
- New devices on the network: After an upgrade, your network might detect new devices or rogue devices holding old IPs.
- Static IP conflicts: If you've set static IPs on devices (like printers, NAS, etc.), those IPs might accidentally be reassigned by the DHCP server.
- Duplicate MAC addresses: This is rare but can happen if network adapters are cloned or reused.
How to fix IP conflicts after a UniFi upgrade
Here’s the step-by-step game plan to tackle IP conflicts. No guesswork — just follow these steps.
1. Reboot everything (simple but powerful)
Sometimes the best solution is the simplest. Rebooting devices forces them to release their old IPs and request new ones from the DHCP server.
How to do it:
- Turn off all UniFi devices (Access Points, Switches, and Controller).
- Power off your modem/router.
- Wait 2-5 minutes (grab a coffee).
- Power on your router first. Let it fully boot.
- Turn on your UniFi devices one at a time.
This process forces every device to request fresh IPs. If the issue is a "stuck IP," this fix will work.
2. Clear DHCP leases
The DHCP lease table stores all the IP addresses assigned to your devices. If old leases remain after an upgrade, conflicts can arise.
How to clear DHCP leases:
- Open the UniFi Controller.
- Go to Settings > Networks.
- Choose the network you want to fix (like LAN or VLAN).
- Scroll to the DHCP Server section.
- Click Clear DHCP Leases.
This will wipe out the list of "who owns which IP" and force devices to ask for new IPs.
Pro Tip: You may also need to reboot affected devices or click the Reconnect button from the UniFi controller.
3. Assign static IPs to important devices
If you have devices like printers, NAS (Network Attached Storage), or servers that you want to always have the same IP, set static IPs for them.
How to set a static IP:
- Go to Settings > Networks in UniFi.
- Scroll to DHCP Reservations or Static IPs.
- Add your device’s MAC address and give it a unique IP (outside the DHCP range).
- Save changes.
If your DHCP pool is 192.168.1.100 - 192.168.1.200, assign static IPs in the 192.168.1.2 - 192.168.1.99 range. This ensures DHCP won't accidentally reuse these IPs.
4. Use the "Forget" option in the UniFi controller
When devices are marked as "Managed by Other" or "Disconnected," you might need to "Forget" and readopt them.
How to forget and re-adopt:
- Open the UniFi Controller.
- Go to Devices.
- Select the device with issues.
- Click Forget.
- Factory reset the device (hold the reset button for 10 seconds).
- Re-adopt it in the UniFi controller.
This forces the device to ask for a new IP.
5. Check for duplicate IPs on your network
Sometimes the problem isn't UniFi — it’s rogue devices. Printers, cameras, or old "zombie" devices could be holding on to an IP.
How to check for duplicates:
- Open the UniFi Controller.
- Go to Clients and Devices.
- Look for devices with duplicate IPs.
- Reboot or Forget these devices.
If a rogue device is causing trouble, give it a static IP or assign a DHCP reservation.
6. Update firmware and UniFi OS
Old firmware = bugs. UniFi releases updates that improve IP handling and device adoption.
How to update firmware:
- Log into the UniFi Controller.
- Go to Settings > System > Updates.
- Update both the Controller software and device firmware.
Don’t skip this step — sometimes, UniFi releases DHCP and IP conflict fixes in updates.
7. Factory reset stubborn devices
If all else fails, factory reset the misbehaving device. Sometimes a device just won’t let go of its old IP.
How to factory reset a UniFi device:
- Hold the reset button on the device for 10 seconds (until the LED flashes).
- Wait for it to reboot.
- Re-adopt the device using the UniFi controller.
Note: Resetting a device erases its settings, but it also clears any IP-related problems.
8. Bonus Tip: Improve DNS Settings
Bad DNS can "feel" like an IP conflict. If your devices can’t resolve IPs, they may get stuck on old leases.
How to improve DNS:
- Go to Settings > Internet > DNS.
- Set Primary DNS to 8.8.8.8 (Google) or 1.1.1.1 (Cloudflare).
This speeds up IP lookups and reduces "phantom conflicts" caused by bad DNS records.
How to avoid IP conflicts in future upgrades
- Use static IPs for critical devices (printers, NAS, servers, etc.).
- Backup your UniFi Controller before upgrading.
- Enable automatic updates to get bug fixes.
- Document static IPs so you know which devices need to be reconfigured.
- Use DHCP reservations for devices that always need the same IP.
Frequently Asked Questions
1. Can I see which devices are causing IP conflicts?
Yes. Open the UniFi Controller and look at Devices. You’ll see "IP conflict detected" messages for problem devices.
2. Can I stop IP conflicts from happening in the future?
Yes. Use static IPs for printers, servers, and important devices. Also, make sure UniFi is on the latest firmware.
3. Why does my UniFi controller show "Managed by Other"?
This happens when a device was adopted by a different controller or an older instance of your controller. Use the Forget and re-adopt method to fix it.
Final thoughts
IP conflicts are annoying, but they’re not a big deal if you know how to handle them. Most of the time, clearing DHCP leases or rebooting devices will solve it. If that doesn’t work, assign static IPs and keep your firmware updated.
If you’re tired of fixing these issues, we at UniHosted offer cloud-hosted UniFi Controller with daily backups, monitoring, and automatic updates. If something breaks, we’ve got your back.
If you would like me to personally walk you through UniHosted, you can schedule a call with me here.
We host UniFi Controllers in the Cloud
Are you ready to take your UniFi Network to the next level? Deploy a UniFi Cloud Controller in minutes and manage your network from anywhere.
Free tier available
Get the best support
Join 1660+ customers
No credit card required