默认选择2.4G
iwconfig 更改channel或frequency报错
Error for wireless request "Set Frequency" (8B04) :
SET failed on device wlan2 ; Device or resource busy.
请教各位大神

这个无需更改，网卡支持就是支持，不支持就是不支持，iwlist wlan2 freq看一下有没有支持5g

wlan2 18 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 12 : 2.467 GHz
Channel 13 : 2.472 GHz
Channel 149 : 5.745 GHz
Channel 153 : 5.765 GHz
Channel 157 : 5.785 GHz
Channel 161 : 5.805 GHz
Channel 165 : 5.825 GHz
Current Frequency:2.462 GHz (Channel 11)
这样子是支持的吧

这就是支持的，打开路由器的wifi 5g，你的网卡应该自动就能识别这个5g频道。

路由器是双频的，我找了另一个支持5G的USB的外置网卡，插上就可以


wlan2 IEEE 802.11abgn ESSID:"xxxx"
Mode:Managed Frequency:2.462 GHz Access Point: 3C:8C:40:4D:38:B0
Bit Rate=54 Mb/s Tx-Power=15 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=70/70 Signal level=-32 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:1 Invalid misc:63 Missed beacon:0

lo no wireless extensions.

wlan1 IEEE 802.11a ESSID:"xxxx" Nickname:"<WIFI@REALTEK>"
Mode:Managed Frequency:5.805 GHz Access Point: 3C:8C:40:4D:38:A0
Bit Rate:54 Mb/s Sensitivity:0/0
Retry:off RTS thr:off Fragment thr:off
Power Management:off
Link Quality=100/100 Signal level=100/100 Noise level=0/100
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0