Monitor interface overview, creating monitor interfaces

CLI way

Monitor interface can be created on any phy since Linux always supports monitor interface mode in software, regardless of driver features on a given WiFi NIC. To create a monitor mode interface wlan0monitor0 on device phy0, use iw phy phy0 interface add wlan0monitor0 type monitor && ip link set wlan0monitor0 up. Resulting monitor mode can be used in wireshark to sniff packets.

Caveats

Your NIC may not support multiple modes at once. I have never seen such a NIC though. You can always see combinations supported by your NIC using iw list | egrep -A2 'valid interface combinations|Wiphy'.

This article has been tested on:

Owner name	NIC name	Vendor code	Device code	Comment
@foxpy	Intel Corporation Wi-Fi 6 AX200 (rev 1a)	8086	2723	Everything is OK
@foxpy	TODO: some old Intel Centrino	TODO	TODO	TODO
@foxpy	TODO: some asus nano-dongle	TODO	TODO	TODO