UniFi - Maintaining Connectivity with your UniFi Devices

A UniFi device with an Offline state has lost communication with its application host meaning that you will be unable to manage its configuration. This does not necessarily mean it has stopped working. As long as it is powered on with connectivity to the rest of your network it will continue operating in a "Self-Run" state using the last known UniFi configuration.

A UniFi device can go offline for a number of reasons, but this is most common for those with third-party equipment, or those that choose to self-host the Network Application instead of using a UniFi OS Console.

Here are the most common reasons why UniFi devices go offline:

Physical Connection Issues

Device connection can be disrupted by faulty cabling, power supply issues, or other problems with your physical networking hardware. First, ensure that your device is being powered by Power-over-Ethernet (PoE). You should also confirm that all of your devices fall within your total PoE Availability. Then, replace its cabling, confirm that both ends are securely connected, and try a new port to rule out physical damage. 

Device Cannot Obtain an IP Address from Your DHCP server

This often occurs for users with a third-party DHCP server that is on a different virtual network than the UniFi device. You can check your server's DHCP leases, or you can use the WiFiman mobile app (Android / iOS) to scan your network to see if you device has an IP address. 

Note: 192.168.1.20 is used as a fallback IP address, so its usage may indicate that your device cannot obtain another IP from your DHCP server.

If your device does not receive and IP address, or receives a fallback IP address (including 169.x.x.x addresses), you likely have a misconfigured network that is blocking your connection. We recommend ensuring that UDP Ports 67 and 68 are open on any firewalls on your network, and then refer to the diagrams in our Virtual Network Connectivity guide for more information.

If your device receives a valid IP address, you should confirm that its assigned default gateway matches that of your actual gateway.

Your Wirelessly Adopted Devices Have Poor Connectivity

A wirelessly adopted device is like any other wireless client. See Optimizing Wireless Client Connectivity for more details.

Firewall Blockages

This is the most common for users self-hosting the Network Application, especially on Windows hosts. For troubleshooting purposes, we recommend temporarily disabling your firewalls to verify if they are preventing your UniFi devices from coming online.

Please also note that some Windows updates can reconfigure your firewall settings. As such, please ensure that your firewall is set to Private. 

Next, verify that TCP Port 8080 and UDP Port 10001 are both open. For instructions on how to verify other required port configurations, see our Required Ports Reference.

If you have any Layer 3-adopted APs, disable any custom firewall rules blocking traffic across VLANs between your UniFi device and the Network Application. Refer to our Virtual Network Connectivity guide for more information.

Your Network Application Host Moved or Its IP Address Changed

If you change the location of your UniFi Network host, your devices could still be attempting to communicate with its old IP address. If the old and new IPs are on the same virtual network (Layer 2), your devices will be able to re-discover and reconnect to your host. 

If you moved the Network host to a new virtual network, however, you must use Layer 3 Adoption to re-establish connectivity. This should only be done by advanced users. Otherwise, we recommend reconfiguring your setup so that your Network Application and UniFi devices are on the same Layer 2 network.

Those who have performed a Layer 3 adoption should also verify if their public IP address has changed. This happens if your ISP provides IP addresses via DHCP. An IP address change will leave your L3-adopted devices still trying to communicate with the old IP address. We recommend using a Dynamic DNS (DDNS) service to avoid this. 

The Management Network Is Not a Member of Your Switch Port Profile

Your UniFi device’s Management Network must be a member of all switch ports. The Management Network configuration is found in the Settings tab of the device’s properties panel, which can be accessed by selecting it on the UniFi Device page. Refer to our Virtual Network Connectivity guide for more information.

Packet Loss and High Latency Between the UniFi Network Application and Device 

The UniFi Network Application has a 60-second disconnection threshold, meaning that it will wait one minute for a response from the device before declaring it disconnected. Packet loss and increased network latency can occasionally trigger device disconnections.