Troubleshooting Tip: Client not connecting to the nearest AP

[magarwal]

Description	This article describes ways to troubleshoot scenarios where clients sometimes stay connected to a farther AP, causing poor performance.
Scope	FortiAP, FortiGate.
Solution	Verify the client's roaming behavior: Understand that Wi-Fi roaming decisions are made by the client device, not the AP. Different devices (laptops, phones, scanners, IoT devices) use different roaming thresholds and algorithms. Check the device’s Wi-Fi driver settings for parameters such as: Roaming aggressiveness (Windows). Wi-Fi band preference. Fast roaming (802.11r/k/v) support. Check AP placement and coverage: Ensure APs are not placed too close, as excessive overlap can confuse client roaming. Avoid placing APs too far apart, which can lead to sticky clients holding on to weak signals. Use site survey tools (Ekahau, NetSpot, FortiPlanner, etc.) to validate coverage. Further reading: Technical Tip: Avoid bad practices when placing FortiAP Technical Tip: New FortiAPs deployment and installation Review Radio Settings on APs: Transmit Power: Too much power can cause sticky clients; too little may cause coverage gaps. Balance carefully. Channel Planning: Avoid overlapping and high interference zones. Use DFS/non-DFS channels wisely. Band Steering: Encourage 5GHz-capable clients to avoid congested 2.4GHz. Further reading: Technical Tip: How to Optimize speed on FortiWiFi Verify Channel Support for the client device: Certain devices may not support all channels (especially DFS or UNII bands). If the nearest AP is on an unsupported channel, the client will connect to a farther AP on a supported one. Verify channel compatibility for your client devices. Confirm whether there are any non-default configurations in the SSIDs (eg. sticky client enable and threshold values). The FortiAP profile may also affect the client's roaming decisions. FortiAP should be on the latest 7.4.6 or 7.6.2 GA and above firmware versions. Example: config wireless-controller vap     edit <SSID_NAME>         set rssi-roaming enable         set rssi 25         set fast-roaming enable         set bss-transition enable     exit end config wireless-controller wtp-profile     edit <WTP_PROFILE>         set txpower-level 3     next end