Re: Does a AP get blacklisted if it fails auth too many times?

Hi Bryce,

On 2/26/25 8:13 AM, Bryce Johnson wrote:
> I have an embedded linux device with silabs wf200 chipset with IWD
> 3.2.  I got logs remotely after the fact so I didn't get to debug this
> one in person.
>
> Every now and then wifi will drop off and usually reconnected.  On
> this particular one it disconnected, tried to reconnect, failed, and
> then never tried again.
>
> <snip>
>
>
> Is there some blacklist that occurs with enough failures?  This device
> ended up sitting like this for a couple hours before it got restarted
> - after the restart IWD immediately reconnected to the AP.

In IWD we have a few special status/reason codes that won't cause an AP 
to be blacklisted, but an auth timeout will blacklist an AP. You will 
generally see this log [1] if there were APs seen but they were all 
blacklisted.

The original reason for the blacklisting was a use case where a specific 
AP is "broken" and repeatedly fails to allow a connection. We wanted to 
exponentially increase the blacklist time for every failure so a client 
would avoid connection disruptions. It really depends on your use case, 
but I also work with headless devices and we control the networks. When 
there is some failure that would normally trigger a blacklist, I'm 
fairly confident this is a transient issue and isn't a "broken" AP (this 
obviously isn't a guarantee though). So in my configuration I've 
actually lowered the maximum blacklist timeout to something like 2-5 
seconds to prevent repeated failures from blacklisting the AP for 
extended periods of time.

[1] 
https://git.kernel.org/pub/scm/network/wireless/iwd.git/tree/src/station.c#n286

>
> <snip>
>
> Thanks
> Bryce
>