wpa_supplicant forcing 2.4GHz?

[mro]

I'm sitting in an OEBB.at train offering free 2.4GHz and 5GHz wifi. In 5GHz I cannot access the captive portal which is needed to accept TOCs. In 2.4GHz I can.

Can I force wpa_supplicant to prefer 2.4GHz and avoid the lottery?

$ freebsd-version -kru ; uname -aKU
14.3-RELEASE-p5
14.3-RELEASE-p5
14.3-RELEASE-p5
FreeBSD mx250.local 14.3-RELEASE-p5 FreeBSD 14.3-RELEASE-p5 GENERIC amd64 1403000 1403000
$ wpa_supplicant -v
wpa_supplicant v2.11
Copyright (c) 2003-2024, Jouni Malinen <j@w1.fi> and contributors
$ inxi -N
Network:
  Device-1: Intel Ethernet I218-LM driver: em
  Device-2: Intel Wireless 7265 driver: iwm

 

[eternal_noob]

You can use the freq_list option and just allow 2.4GHz frequencies.

 

[zsolt]

Hi,

You can scan for the freqvencies like this:

$ doas ifconfig wlan0 list freq
Channel   1 : 2412  MHz 11g ht       Channel  60 : 5300* MHz 11a ht      
Channel   2 : 2417  MHz 11g ht       Channel  64 : 5320* MHz 11a ht      
Channel   3 : 2422  MHz 11g ht       Channel 100 : 5500* MHz 11a ht      
Channel   4 : 2427  MHz 11g ht       Channel 104 : 5520* MHz 11a ht      
Channel   5 : 2432  MHz 11g ht       Channel 108 : 5540* MHz 11a ht      
Channel   6 : 2437  MHz 11g ht       Channel 112 : 5560* MHz 11a ht      
Channel   7 : 2442  MHz 11g ht       Channel 116 : 5580* MHz 11a ht      
Channel   8 : 2447  MHz 11g ht       Channel 120 : 5600* MHz 11a ht      
Channel   9 : 2452  MHz 11g ht       Channel 124 : 5620* MHz 11a ht      
Channel  10 : 2457  MHz 11g ht       Channel 128 : 5640* MHz 11a ht      
Channel  11 : 2462  MHz 11g ht       Channel 132 : 5660* MHz 11a ht      
Channel  12 : 2467* MHz 11g ht       Channel 136 : 5680* MHz 11a ht      
Channel  13 : 2472* MHz 11g ht       Channel 140 : 5700* MHz 11a ht      
Channel  36 : 5180* MHz 11a ht       Channel 149 : 5745* MHz 11a ht      
Channel  40 : 5200* MHz 11a ht       Channel 153 : 5765* MHz 11a ht      
Channel  44 : 5220* MHz 11a ht       Channel 157 : 5785* MHz 11a ht      
Channel  48 : 5240* MHz 11a ht       Channel 161 : 5805* MHz 11a ht      
Channel  52 : 5260* MHz 11a ht       Channel 165 : 5825* MHz 11a ht      
Channel  56 : 5280* MHz 11a ht

then you can edit your /etc/wpa_supplicant.conf and inserting the freqs like this:

freq_list=2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472

 

[Erichans]

freq_list is documented in:
/usr/share/examples/etc/wpa_supplicant.conf
wpa_supplicant.conf - src

 

[nxjoseph]

freq_list is documented in:
/usr/share/examples/etc/wpa_supplicant.conf
wpa_supplicant.conf - src

But not in manpage

I used to specify 5GHz band's mac address as bssid (no quotes) in the wpa conf