Hello, When I use 2.4Ghz band with -only one- AP (running on top of hostapd) I get a (additional) list of frequencies at 5Ghz. When I do "iw dev .. scan" BSS 02:00:00:00:04:00(on sta1-wlan0) -- associated TSF: 1566905272877856 usec (18135d, 11:27:52) freq: 2422 beacon interval: 100 TUs capability: ESS ShortSlotTime (0x0401) signal: -34.00 dBm last seen: 0 ms ago Information elements from Probe Response frame: SSID: simplewifi Supported rates: 1.0* 2.0* 5.5* 11.0* 6.0 9.0 12.0 18.0 DS Parameter set: channel 3 ERP: Barker_Preamble_Mode Extended supported rates: 24.0 36.0 48.0 54.0 Extended capabilities: * Extended Channel Switching * Multiple BSSID * SSID List * Operating Mode Notification BSS 02:00:00:00:04:00(on sta1-wlan0) TSF: 1566905274269230 usec (18135d, 11:27:54) freq: 5180 beacon interval: 100 TUs capability: ESS ShortSlotTime (0x0401) signal: -34.00 dBm last seen: 0 ms ago Information elements from Probe Response frame: SSID: simplewifi Supported rates: 1.0* 2.0* 5.5* 11.0* 6.0 9.0 12.0 18.0 DS Parameter set: channel 3 ... BSS 02:00:00:00:04:00(on sta1-wlan0) TSF: 1566905274269230 usec (18135d, 11:27:54) freq: 5200 beacon interval: 100 TUs capability: ESS ShortSlotTime (0x0401) signal: -34.00 dBm last seen: 0 ms ago Information elements from Probe Response frame: SSID: simplewifi Supported rates: 1.0* 2.0* 5.5* 11.0* 6.0 9.0 12.0 18.0 DS Parameter set: channel 3 ... and so on (please notice that channel number and frequency).. iw dev scan returns all the 5Ghz frequencies defined in https://github.com/torvalds/linux/blob/master/drivers/net/wireless/mac80211_hwsim.c#L328 It happens only when wmediumd is being used. When hostapd is running with 5Ghz it seems to work as expected, since iw returns only the AP running at 5Ghz. In other words, the problem occurs only when hostapd is running at 2.4Ghz. I noticed that it happens from kernel 4.18. If I comment https://github.com/torvalds/linux/blob/b55f3b841099e641bdb2701d361a4c304e2dbd6f/drivers/net/wireless/mac80211_hwsim.c#L2838, iw returns only 2422Mhz. However, I couldn't find the reason for such problem. There could be some problem with mac80211_hwsim, or am I missing something here? Best Regards, Ramon Fontes
