The wireless card of the weather station computer in the shed is dual-band but with only a 2.4 GHz capable antenna. Since the house access-point is configured to support both 2.4 GHz and 5 GHz channels the system sometimes selects the 5 GHz access and keeps having serious packet loss. I looked at ways to convince the driver to select 2.4 GHz channels only but found none, but then I found out wpa_supplicant can do this. But I configure wpa_supplicant through wpa-* options in /etc/network/interfaces so I had to find out how to configure it using those. The manpages for the interfaces file is very limited on the wpa-* options, but I found an explanation that a lot of wpa_supplicant options are supported, including the one to select frequencies. The sneaky part is that the option in wpa_supplicant.conf is freq_list and the option in /etc/network/interfaces is wpa-freq-list. A rather complete list can be found at Where can I find a full list of wpa-* options for the interfaces file? - superuser.com. So now I have in /etc/network/interfaces:auto wlan0 iface wlan0 inet dhcp wpa-ssid default wpa-psk VerySecret wpa-freq-list 2412 2417 2422 2427 2432 2437 2442 2452 2457 2462 2467 2472The ideal solution is to order a dual-band (2.4 GHz and 5 GHz) antenna. Update: Noticeable absent are channels 12 and 13 which are available for regulatory domain NL but are not listed when I ask the driver for available channels:koos@ritchie:~$ /sbin/iwlist wlan0 chann wlan0 19 channels in total; available frequencies : Channel 01 : 2.412 GHz Channel 02 : 2.417 GHz Channel 03 : 2.422 GHz Channel 04 : 2.427 GHz Channel 05 : 2.432 GHz Channel 06 : 2.437 GHz Channel 07 : 2.442 GHz Channel 08 : 2.447 GHz Channel 09 : 2.452 GHz Channel 10 : 2.457 GHz Channel 11 : 2.462 GHz Channel 36 : 5.18 GHz Channel 40 : 5.2 GHz Channel 44 : 5.22 GHz Channel 48 : 5.24 GHz Channel 52 : 5.26 GHz Channel 56 : 5.28 GHz Channel 60 : 5.3 GHz Channel 64 : 5.32 GHz Current Frequency:2.462 GHz (Channel 11)And now I wonder why those are missing.