hostapd error

Ann Lo at
Fri Mar 25 17:24:44 PDT 2016

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?


On Fri, Mar 25, 2016 at 3:26 PM, Ben Greear <greearb at> wrote:
> On 03/25/2016 03:14 PM, Ann Lo wrote:
>> Hi,
>> When I run hostapd using 80 MHz channel, sometimes I get the following
>> error. Would you provide information on this error? What is the
>> solution when this error happens?
>> Switch own primary and secondary channel due to BSS overlap with
>> 9c:d6:43:2e:8a:28
> This is normal when it detects another AP on overlapping channel
> using a different primary channel.
>> Using interface uap0 with hwaddr 82:14:3e:f0:9c:b0 and ssid "caytestac"
>> Failed to set beacon parameters
>> hostapd: Interface initialization failed
> Please run hostapd with verbose logs and see if it gives more details about
> what fails.
> Thanks,
> Ben
> --
> Ben Greear <greearb at>
> Candela Technologies Inc

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