Problem connecting to internet using dwa-171 as second wireless device

[peterg17]

Hi,
I have a laptop I connect to the internet with using my mobile phones hotspot. I have several wifi devices (printer tv) that currently connect to my mobile, and every time I leave home all these devices disconnect. I decided to set up my laptop as a permanent hotspot host and add a second wireless device that connects to my mobile phone and through that onto the internet.

I ended up getting a d-link DWA-171 usb wireless adapter. I downloaded and compiled the rtl8821au kernel driver. I use wpa_supplicant in a script run by ifup from a systemctl service. My wpa.conf file has nothing more than an ssid and a psk. I had to add a -D option to wpa_supplicant (-D nl80211,wext) to get it to work (from wpa_supplicant log).

When I configure the device, internet does not work. The ping and dig utilities work for a minute or so after changing from the primary wireless device, then stops working. The device is apparently configured ok. There is no difference in the route -n output compared with using the primary device. The file /etc/resolv.conf is identical. The only difference is with the iwconfig output, which is

enx9cd6435b7223 IEEE 802.11bgn ESSID:"HTC Portable Hotspot 3E2C" Nickname:"<WIFI@REALTEK>"
Mode:Managed Frequency:2.437 GHz Access Point: 40:4E:36:1A:EF:92
Bit Rate:87 Mb/s Sensitivity:0/0
Retry : off RTS thr: off Fragment thr: off
Encryption key:****-****-****-****-****-****-****-**** Security mode: open
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


With the primary device, which works, the iwconfig output is:
wlan0 IEEE 802.11bgn ESSID:"HTC Portable Hotspot 3E2C"
Mode:Managed Frequency:2.437 GHz Access Point: 40:4E:36:1A:EF:92
Bit Rate=65 Mb/s Tx-Power=15 dBm
Retry short limit:7 RTS thr: off Fragment thr: off
Encryption key: off
Power Management: off
Link Quality=70/70 Signal level=-35 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:1 Invalid misc:235 Missed beacon:0



and the wpa_supplicant log when connecting with the errant device is:

Successfully initialized wpa_supplicant
nl80211: Could not configure driver mode
nl80211: deinit ifname=enx9cd6435b7223 disabled_11b_rates=0
ioctl[SIOCSIWAP]: Operation not permitted
ioctl[SIOCSIWENCODEEXT]: Invalid argument
ioctl[SIOCSIWENCODEEXT]: Invalid argument
enx9cd6435b7223: Trying to associate with 40:4e:36:1a:ef:92 (SSID='HTC Portable Hotspot 3E2C' freq=2437 MHz)
enx9cd6435b7223: Association request to the driver failed
enx9cd6435b7223: Associated with 40:4e:36:1a:ef:92
enx9cd6435b7223: WPA: Key negotiation completed with 40:4e:36:1a:ef:92 [PTK=CCMP GTK=CCMP]
enx9cd6435b7223: CTRL-EVENT-CONNECTED - Connection to 40:4e:36:1a:ef:92 completed [id=0 id_str=]

So looking forward for ideas on how to solve this. I suspect the problem is something to do with the encryption key setting in the iwconfig output.

[peterg17]

I have created a more extensive wpa_supplicant output on the failing connection, using the -dd switch.
I tried to upload as an attachment, but kept getting "invalid file" error.
Cannot see any obvious problems in it.

[peterg17]

The arp tool says the hardware address in incomplete, even though ifconfig for example provides the hardware address. There is also no HWType or Flags data, compared to the normal working wifi setup.

[peterg17]

I discovered that ifup invokes wpa_supplicant.
So I stopped using any scripts and set up an /etc/network/interfaces entry.
The entry does something like:


iface wifi_client inet dhcp
wpa-logfile /var/log/wpa_supplicant.log
wpa-ssid "HTC Portable Hotspot 3E2C"
wpa-psk [My password psk]
wpa-maint-debug


This works, as it connects to the internet via my mobile, with the command
$ ifup wlan0=wifi_client


but the corresponding command for the usb device fails with behaviour as described above.
However the usb device does connect to the phone and obtains an ip address via dhcp.
The phone says it has the connection. The firewall is diabled. But no internet.
I log into wpa with wpa_cli and get the status. The status with the failing device is:


bssid=40:4e:36:1a:ef:92
freq=0
ssid=HTC Portable Hotspot 3E2C
id=0
mode=station
pairwise_cipher=CCMP
group_cipher=CCMP
key_mgmt=WPA2-PSK
wpa_state=COMPLETED
ip_address=192.168.1.136
address=9c:d6:43:5b:72:23
uuid=13fedc65-6913-5f7c-a5c6-e441f1a5f9b8


Why the frequency is zero is a bit of a mystery to me.

[peterg17]

Hi,
I placed my question on linuxquestions and did receive a reply, without resolving the problem so have continued to document the problem there.
I have resolved it to an apparent driver error, where the transmit tasklet has an illegal internal state.
Investigations are continuing.

[peterg17]

Solution discussed in this thread.
https://www.linuxquestions.org/questions/linux-wireless-networking-41/no-internet-with-second-wireless-device-d-link-dwa-171-a-4175632693/

Serious bug in the driver. Usable now, but will replace directly.