Re: strange behavior with synthetic ap0

[Denis Kenzior <denkenz@gmail.com>]

Hi Keith,

What does:
iw phy | grep -3 'interface combinations'
say?

Typical WiFi chips support only a single channel (e.g. #channels <= 1)

 >
> How do I ensure it is on the same frequency? I would think that I
> would have to change the freq to whatever the freq of the SSID I am
> connecting to. The process would then have to be: query the SSID for a
> freq then stop and restart the AP... Wouldn't this disconnect the AP0
> from whatever is connected to it?

There should be a way to tell the AP to switch the current channel.  The AP will 
inform clients about the channel switch and they should end up at the new 
frequency without losing connectivity.

> 
> A bit oif background, I am trying to write a python script to do a bit
> of magic. We use connman as the front end and iwd as the wifi
> controller and there is no real good way to have this headless,
> embedded device always allow a connection, so I am trying to get a
> python script to monitor dbus and when it looses its wlan0 connection
> to start ap0 and allow a connection that way unless it 'sees' an SSID
> it already recognizes. In that case, I am having is down the ap0 then
> connect to the SSID on wlan0. That works, but it must be serial: shut
> down ap0 before connecting to SSID on wlan0 or it complains that the
> password is bad.
> 
> I may be mistaken, but I think that a year or so ago (kernel 5.x or
> 6.1) it used to actually allow both simultaneously.

Different firmware?

> 
> I built a kernel last night so that I nave nlmon available to query
> what is being passed if that is needed.
> 

I doubt nlmon will show anything useful.  You'd need to have information about 
how the firmware / kernel driver works and any constraints.

Regards,
-Denis