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I recently purchased a USB Wi-fi Adapter from Amazon for my Ubuntu server. The reviews say that it is compatible with Ubuntu 20.04 but the drivers for Ubuntu don't come on the included driver CD. I was wondering where I could find the correct drivers for the adapter. The adapter is linked below. If anyone can help, that'd be very appreciated.

The adapter model is the UGREEN USB WiFi Adapter AC650: Amazon product page.

journalctl --follow interesting lines:

Sep 04 06:07:47 bzoit snapd[754]: starteengine.go:150: state ensure error: persistent network error: Get https://api.snapcraft.io/api/v1/snaps/sections: dial tcp: lookup api.snapcraft.io: Temporary failure in name resuolution
Sep 04 06:08:21 bzoit kernel: usb 1-14: USB disconnect, device number 4
Sep 04 06:08:58 bzoit sudo[1146]: pam_unix(sudo:auth): authentication failure; logname=wilsont uid=1000 euid=0 tty=/dev/tty1 ruser=wilsont rhost= user=wilsont
Sep 04 06:09:31 bzoit kernel: usb 1-14: new high-speed USB device number 5 using xhci_hcd
Sep 04 06:09:31 bzoit kernel: usb 1-14: New USB device found, idVendor=0bda, idProduct=c811, bcdDevice= 2.00
Sep 04 06:09:31 bzoit kernel: usb 1-14: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Sep 04 06:09:31 bzoit kernel: usb 1-14: Product: 802.11ac NIC
Sep 04 06:09:31 bzoit kernel: usb 1-14: Manufacturer: Realtek
Sep 04 06:09:31 bzoit kernel: usb 1-14: SerialNumber: 123456

lsusb output

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 1c4f:0026 SiGma Micro Keyboard
Bus 001 Device 004: ID 0bda:c811 Realtek Semiconductor Corp. 802.11ac NIC
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsusb -v output for wifi adapter (photos of a screen showing a terminal):

photo of a screen showing a terminal

another photo of a screen showing a terminal

Nmath
  • 12,333
Wilson T.
  • 31

1 Answers1

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From journalctl results you've posted, your USB wireless adapter, idVendor=0bda, idProduct=c811, needs rtl8821CU drivers.

You can install the drivers from this GitHub repo:

sudo apt update
sudo apt install build-essential git dkms
git clone https://github.com/brektrou/rtl8821CU.git
cd rtl8821CU
chmod +x dkms-install.sh
sudo ./dkms-install.sh

Ref: https://askubuntu.com/a/1264759/928088

Jags
  • 2,176
  • Would I be able to download the repo onto a flash drive and run it on the server? Or would I have to download the repo from the internet? It would just be very difficult to get hold of a temporary internet connection via Ethernet. – Wilson T. Sep 08 '21 at 22:06
  • See: how to install software offline. It would be better (easier) if you can connect via Ethernet to do this. – Nmath Sep 08 '21 at 22:39
  • @wilson-t besides Nmath's comment, another option is to tether your phone temporarily. – Jags Sep 09 '21 at 06:51
  • @Jags I've installed the drivers, the net-tools package, and the wireless-tools package. But still, when I run iwconfig, the adapter doesn't show up. – Wilson T. Sep 16 '21 at 16:40
  • @wilson-t please post output of ip a and of lsmod. Also, you may need to reboot the system after drivers installation. Thanks. – Jags Sep 16 '21 at 18:33
  • @Jags I tried rebooting after installing drivers, but still no luck. – Wilson T. Sep 16 '21 at 20:54
  • @Jags ip a Output: https://pastebin.com/Cxjamb2r lsmod Output: https://gyazo.com/8c5283f886d2ba341adf730e29706b98 , https://gyazo.com/94c6b30ee35049b57c3fb2a5bdbb082b – Wilson T. Sep 16 '21 at 21:14
  • @wilson-t from the pictures you've linked, it sounds like rtl8821CU driver is not loaded. Did you get any errors when you installed the driver? – Jags Sep 16 '21 at 21:42
  • @Jags When I installed the drivers, I got no errors. I followed the directions you posted above when installing the drivers. – Wilson T. Sep 16 '21 at 22:06
  • What is the result of the terminal command: sudo modprobe 8821cu – chili555 Sep 16 '21 at 23:03
  • @wilson-t you may have not gotten the comment from chili555, so asking the same question: "What is the result of the terminal command: sudo modprobe 8821cu." Also, since you're posting the pictures instead of text, you may not have connectivity, so let me ask you, how did you install the drivers? Thanks. – Jags Sep 17 '21 at 11:48