Frequently Asked Question
UniFi Wi-Fi connects but shows 169.254 or cannot obtain an IP address. What should I check?
QUICK ANSWER
A connected Wi-Fi signal does not guarantee that DHCP can reach the client. Check the SSID's VLAN, every upstream port and the DHCP service for that network.
Applies to: UniFi APs using a separate client VLAN, with a UniFi or third-party router providing DHCP.
Work through these checks
- Record the affected SSID, VLAN ID, client IP and AP uplink port. A 169.254 address usually means that an IPv4 DHCP lease was not obtained; it does not identify which device caused the failure.
- Check that the SSID is assigned to the intended network. On a third-party gateway, create the matching VLAN interface, subnet and DHCP scope there as well.
- Trace the VLAN through the AP's switch port and every uplink to the gateway. The client VLAN must be allowed as tagged traffic along the intended trunk path. Keep the management/native VLAN consistent with the design.
- Check DHCP scope capacity and service status. Compare with one wired test port deliberately assigned to the same client VLAN. Change one port at a time and keep management access available.
Confirm the result
Reconnect one test client. It should receive an address, gateway and DNS settings from the correct subnet, then reach the gateway and internet.
If you need help
Include these details in your ticket: A simple port/VLAN diagram, affected SSID, DHCP server location and a redacted client IP configuration. Do not factory-reset the site to fix a lease problem.
Updated 261107