Re: Wi-Fi speeds degrade from 600Mps to 30Mps while using WPA2 security, but not on open network, shortly after ISP firmware upgrade.

[Johannes Berg <johannes@sipsolutions.net>]

On Thu, 2026-04-16 at 08:34 -0400, Benson Bear wrote:
> 
> Thanks again.  Sadly it looks like linux (the wpa_supplicant) is
> in the wrong here, just reasoning about it.   I assume the AP
> always offers the option.   It doesn't get a rejection before it
> even makes an offer.   So that means when it offered it when
> PMF was not disabled in the client, the client must have
> accepted the offer.   Because we know in the other case,
> when PMF *is* disabled, that it works fine, which must mean
> the AP received correctly a rejection of the offer.  So had
> the client sent a rejection in the first case, like it did in the
> second, there is no reason the AP would not have accepted
> that rejection.  So the client must have sent an acceptance.

Doesn't mean they both negotiated the use correctly, or even encrypted
the frames correctly. Could even be that they both agreed on PMF, but
then the AP sent unencrypted AddBA request (or response, depending on
the direction) and the client dropped it, or any other weird things.

> Not iron clad, because maybe the AP is just plain crazy.

My bet would be on that but we'd have to see a sniffer capture. But in 
general, we definitely know that PMF works with Linux/wpa_s and WiFi7
requires it, etc.

johannes