hostapd error

Ben Greear greearb at
Fri Mar 25 17:49:57 PDT 2016

On 03/25/2016 05:24 PM, Ann Lo wrote:
> Hi Ben,
> Thanks for your information and suggestion. Using -dd option, there
> are more information from hostapd, including:
> nl80211: Beacon set failed: -16 (Device or resource busy)
> Further investigation result is that this happens in the following scenario:
> 1) hostapd runs OK at channel 36 using 80 MHz width.
> 2) wpa_supplicant (using the same radio) tries to connect to a remote
> AP on channel 36 using 20 MHz width.
> 3) hostapd is restarted at this point.
> 4) When hostapd comes up again, it gets the above error.
> 5) At this point, wpa_supplicant connects successfully.
> The radio requires AP and client using the same channel. Does this
> mean that the channel width must be the same?

Channel width does not need to be the same, but the primary channel
must be.

You probably need a patch I put into hostapd to force not switching
the primary channel when running multiple interfaces on a single radio.


Ben Greear <greearb at>
Candela Technologies Inc

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