On Sun, Mar 22, 2026 at 02:56:52PM +0000, Klemens Nanni wrote:
> I tried this against an AP that supports 160 MHz windows and shows
> other devices using them, but my notebook does not start doing so:

If your AP does not display an Rx rate which corresponds to 160 MHz
that would indeed suggest that it's not working as it should.
 
> iwx0 at pci0 dev 20 function 3 "Intel Wi-Fi 6 AX211" rev 0x01, msix
> iwx0: hw rev 0x370, fw 77.f92b5fed.0, pnvm 285b3568, address a0:29:42:f6:8f:1a
> 
> That is, 'ifconfig wlan' keeps showing 'chan 60' and 'ifconfig wlan can'
> lacks channel 163, which it should, if I understand this table correctly:
> https://en.wikipedia.org/wiki/List_of_WLAN_channels#5_GHz_(802.11a/h/n/ac/ax/be)
> 

That is normal. ifconfig will only display the 20MHz primary channel number.
This number can be found in beacons. The primany channel may differ from
the channel the beacon was received on because APs using wide channels will
transmit a separate beacon on each 20 MHz channel occupied by the AP's wide
channel configuration. Otherwise, legacy clients wouldn't register the AP's
presence on overlapping 20 MHz channels.

The channel width can be adjusted dynamically by the AP. It is announced in
the VHT operation element of beacons. Regulatory settings factor into this.

The client can in theory use a different channel width for every data frame
it sends to the AP. If 160 is supported then so are 80, 40, and 20.
iwx(4) firmware will pick a Tx rate and channel width for each data frame,
based on internal heuristics.