Debian Stretch release – wifi woes with NetworkManager – quick fix

Goal;
Get all four USB Wifi Dongles working. Most importantly I want the AC one to work. I read lots of articles that it didn’t work. Well I got it working in Debian Stretch with Network Manager (nmcli).

Some of the story;
I was remembering that Debian Jessie was fantastic with Wifi. So it had to be something with stretch.

A little over a month and half later, I’m trying the four wifi dongles I have, to see which one actually works.

Tonight, guess what? None of the four USB wifi adapters I have are working. (They will, just continue reading.)
All the tools I’m familiar with are not installed either. Just NetworkManager (the GUI tool) and “iw” on the command line, and ifconfig.

Four USB Wifi Dongles;
Edimax EW-7811Un – Edimax Technology Co., Ltd EW-7811Un 802.11n Wireless Adapter [Realtek RTL8188CUS]

ASUS USB N13 – iface wlx20cf30a29c9a

Netgear A6210 AC – just ID’s as Netgear Inc.
https://github.com/jurobystricky/Netgear-A6210 << using this driver
modprobe mt7662u_sta

Netgear High Speed Wifi USB adapter – NetGear, Inc. WNDA4100 802.11abgn 3×3:3 [Ralink RT3573]

This post assisted me;
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=839605

And the only change I needed from it was as follows;
sudo vi /etc/NetworkManager/NetworkManager.conf #add these two lines
[device-mac-randomization]
wifi.scan-rand-mac-address=no

sudo service network-manager restart

Four Network Devices;
Netgear, Inc. WNDA4100 802.11abgn 3×3:3 [Ralink RT3573] = Confirmed Working.
wlx6cb0ceefa32d: connected to faith-5G
“NETGEAR WNDA4100″
wifi (rt2800usb), 6C:B0:CE:EF:A3:2D, hw
ip4 default
inet4 192.168.1.235/24
inet6 fe80::b0a6:c0c0:dbc7:f2c4/64

iwconfig
wlx6cb0ceefa32d IEEE 802.11 ESSID:”faith-5G”
Mode:Managed Frequency:5.745 GHz Access Point: …………
Bit Rate=300 Mb/s Tx-Power=20 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
Link Quality=70/70 Signal level=-29 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:54 Missed beacon:0

Netgear A6210 AC = Confirmed working
nmcli shows;
wlan0: unmanaged
“NETGEAR A6210”
wifi (RALINK WLAN), 00:00:00:00:00:00, hw, mtu 1500

Confirmed working; (I had to reboot to get it online)
wlan0: connected to Wi-Fi connection 1
“NETGEAR A6210”
wifi (usb), 6C:B0:CE:E8:DD:11, hw, mtu 1500
inet4 192.168.1.34/24
inet6 fe80::7936:ee8f:711b:9356/64

ASUS USB N13 = Confirmed Working.
A reboot brought it back online. I can scan access points with iwlist wlx20cf30a29c9a scanning
dhcp discover fails.
‘device not managed’ by NetworkManager
Ok I looked that up; https://wiki.debian.org/NetworkManager
then removed wlan0 and wlx20cf30a29c9a from /etc/network/interfaces and now wifi works on the ASUS USB N13!

Edimax = Confirmed Working.

root@BillsStretch:~# nmcli
enp4s0: connected to Wired connection 1
“Qualcomm Atheros Killer E220x Gigabit Ethernet Controller”
ethernet (alx), D4:3D:7E:EB:49:06, hw, mtu 1500
ip4 default
inet4 192.168.1.231/24
inet6 fe80::d63d:7eff:feeb:4906/64

wlx20cf30a29c9a: connected to faith 2
“Ralink 802.11 n WLAN”
wifi (rt2800usb), 20:CF:30:A2:9C:9A, hw, mtu 1500
inet4 192.168.1.97/24
inet6 fe80::26de:bce2:c87:e589/64

lo: unmanaged
loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536

DNS configuration:
servers: 192.168.1.1
interface: enp4s0

servers: 192.168.1.1
interface: wlx20cf30a29c9a

Conclusion;

Don’t install any extra tools.  Stick with nmcli nmtui and NetworkManager. Dig deeper if the setting I list doesn’t work.

Rest assured, if your wifi worked before, you can probably get it to work again in Linux. See the solution I used to get NetworkManager to working on stretch.

Quick Notes;
A. Do not add any interfaces to /etc/network/interfaces if you plan to use the tools nmcli and network manager in Debian stretch.

B. The change listed above about the mac address in NetworkManager.conf got all my wifi usb dongles to work.

C. Hot Swapping some of the dongles resulted in the wifi usb dongle not working. restarting the network-manager after hotswap didn’t always work. A full reboot got it working each time however.

D. Notice any Strange MAC address’s as all Zero’s? 00:00:00:00:00  time to do a full reboot (well you could probably rmmod and modprobe/insmod it again, anything to prod it to reload the firmware.)  Frankly the reboot is the easiest in my mind.

E. Check your dmesg.  Some dmesg stuff can be misleading.  The AC6210 kept spitting out illegal channel information and wouldn’t work with the WPA Supplicant commands.  It will however work with nmcli/NetworkManager.