Description
This article describes how to troubleshoot FortiAP unable to broadcast an SSID on the 6E band.
Scope
FortiAP 6E.
Solution
Ensure both FortiAP and FortiGate are using the latest GA version of each of these products. Fortinet recommends using the latest releases, v7.6, on both FortiGate and FortiAP or higher. Check that there are no regionalization conflicts and resolve them appropriately (country code mismatch): Technical Note: Changing country setting on a wireless controller.
The most likely reason a 6 GHz SSID cannot be observed being broadcast is that SSID broadcasting in the 6 GHz band works differently from the conventional 2.4 GHz and 5 GHz bands.
There are two ways WiFi 6E channel discovery works: Out-of-Band Discovery and In-Band Discovery.
- Out-of-Band Discovery: Uses a method called Reduced Neighbor Report. Essentially, it broadcasts the 6GHz SSID channel through the 2.4GHz and 5GHz beacon frames.
- Enable the 2.4 GHz and/or 5 GHz band, and 6 GHz channels will be discoverable.
- Check the beacon frames in an over-the-air packet capture, the 6 GHz SSID will be announced there.
- This discovery method is preferred by client devices and access points.
- In-Band Discovery: Client devices scan the 6GHz band directly but only on a Preferred Scanning Channel (PSC) set. This method is unreliable because it varies between different client device vendors. For example, some Apple devices capable of 6E only perform Out-of-Band Discovery to discover 6GHz SSIDs.
- For 6 GHz SSIDs to be directly detectable, they need to be on a Preferred Scanning Channel (PSC).
- PSC channels: 5, 21, 37, 53, 69, 85, 101, 117, 133, 149, 165, 181, 197, 213, 229.
- If the Wi-Fi device supports the In-Band Discovery method, specify that the 6 GHz SSID channel is channel 5 or one of these.
