Start With the Symptom
This troubleshooting center organizes common UniFi problems by symptom instead of product category. Each guide starts with low-risk checks and explains when the problem is likely configuration-related, cabling-related or better handled remotely.
UniFi device will not adoptDiscovery, inform/adoption state, controller reachability and reset considerations.
Access point keeps disconnectingPoE, cabling, uplinks, firmware consistency and controller history.
Network feels slow despite fast internetSeparate ISP speed from Wi-Fi, switching, roaming and client problems.
VLAN or guest network not workingNetwork definitions, switch-port tagging, DHCP and firewall policy.
Site-to-site VPN not connectingWAN reachability, addressing conflicts, peer settings and routing.
UniFi Protect camera offlinePoE, switch port, cable, NVR reachability and physical-link checks.
PoE device will not power onPoE standard, switch budget, cabling and port-level power checks.
Wi-Fi roaming problemsAP placement, transmit power, client behavior and RF overlap.
High latency or packet lossSeparate LAN, Wi-Fi, switch and ISP causes methodically.
Gateway offline or unreachablePower, LAN reachability, WAN service and management-path checks.
Access point keeps disconnectingPoE, cabling, uplinks, firmware consistency and controller history.
Network feels slow despite fast internetSeparate ISP speed from Wi-Fi, switching, roaming and client problems.
VLAN or guest network not workingNetwork definitions, switch-port tagging, DHCP and firewall policy.
Site-to-site VPN not connectingWAN reachability, addressing conflicts, peer settings and routing.
UniFi Protect camera offlinePoE, switch port, cable, NVR reachability and physical-link checks.
PoE device will not power onPoE standard, switch budget, cabling and port-level power checks.
Wi-Fi roaming problemsAP placement, transmit power, client behavior and RF overlap.
High latency or packet lossSeparate LAN, Wi-Fi, switch and ISP causes methodically.
Gateway offline or unreachablePower, LAN reachability, WAN service and management-path checks.
Avoid Changing Several Things at Once
Good troubleshooting isolates one layer at a time: internet/WAN, gateway, switching, cabling, wireless, DHCP/DNS and application behavior. Record the original setting before changing it so you can reverse an unsuccessful test.
Remote Troubleshooting
If the network is reachable but the cause is not obvious, many controller, VLAN, VPN, adoption and configuration problems can be reviewed remotely. See nationwide remote UniFi support.