[SOLVED] USB WIFI Realtek 8192SU

[SOLVED] USB WIFI Realtek 8192SU

Postby gregM » May 29th, '19, 12:05

Hi All,
Trying to get my Realtek USB WiFi adapter to connect to access points.
Setting up the adapter in MCC or the net applet, all the access points are visible, but attempting to connect fails.

Using the DHCP auto detect no address is assigned to the adapter, due I guess to access point not responding.
If I manually set IP and DNS the adapter will assign these to the interface, but the ESSID shows b'' in the net_applet monitor screen.

I have managed to get the ESSID to show a valid access point name , and can then bring up the network with command
ifup <wireless-interface-name>

Hardware detection shows the wireless dongle using the 8712 driver.
Using Mageia 7 beta 2 (now have limited internet access for further upgrading).

Here is the hardware and command line output :-
Code: Select all
Detect Hardware MCC
Vendor: ‎Manufacturer Realtek
Description: ‎RTL8191S WLAN Adapter
Media class: ‎
Bus: ‎USB
Bus PCI #: ‎1
PCI device #: ‎3
Vendor ID: ‎0x0bda
Device ID: ‎0x8172
Module: ‎r8712u

Command line usb-devices :-
T:  Bus=01 Lev=02 Prnt=02 Port=01 Cnt=01 Dev#=  3 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0bda ProdID=8172 Rev=02.00
S:  Manufacturer=Manufacturer Realtek
S:  Product=RTL8191S WLAN Adapter
S:  SerialNumber=00e04c000001
C:  #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=500mA
I:  If#=0x0 Alt= 0 #EPs= 4 Cls=ff(vend.) Sub=ff Prot=ff Driver=r8712u

Command line
[root@homeport greg]# iwconfig (before config ESSID)

wlp0s26u1u2  unassociated  Nickname:"rtl_wifi"
          Mode:Auto  Access Point: Not-Associated   Sensitivity:0/0 
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

Command line
[root@homeport greg]# iwconfig (after manual config of ESSID)
 iwconfig wlp0s26u1u2 essid teleport

wlp0s26u1u2  IEEE 802.11bg  ESSID:"teleport"  Nickname:"rtl_wifi"
          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:04:ED:C9:C9:94   
          Bit Rate:54 Mb/s   Sensitivity:0/0 
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:0000-0000-00   Security mode:open
          Power Management:off
          Link Quality=0/100  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

Note here the ESSID is showing correctly (teleport), where the net_applet shows ESSID incorrectly (b'teleport')

Routes look good and can ping gateway with LAN card
Command line with LAN card connected
[root@homeport greg]# route         
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         home.gateway         UG    10     0        0 enp3s0   U     0      0        0 enp3s0
link-local     U     1002   0        0 enp3s0

With WIFI connected, routes look same but WIFI card but cant ping gateway.
[root@homeport greg]#  iwconfig wlp0s26u1u2 essid teleport                       
[root@homeport greg]# ifup wlp0s26u1u2
[root@homeport greg]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         _gateway         UG    35     0        0 wlp0s26u1u2   U     0      0        0 wlp0s26u1u2
link-local     U     1003   0        0 wlp0s26u1u2

In summary :-

Firewall is turned off to isolate that potential problem

Is the wifi dongle using the wrong driver (r8712u) ?
I have installed the latest realtek firmware driver rpm rtlwifi-firmware to no effect...

I have run "rfkill unblock all" to no effect.

net_applet can see all the access points, but fails to connect even to unsecured points.
In net_applet 'monitor' the ESSID is showing b'' not the access point name, untill I manually run
iwconfig wlp0s26u1u2 essid teleport
after this command the monitor ESSID still shows the ESSID as b'teleport'. Why is that b char being reported ?
The interface is not able to be set to 'up' untill after the ESSID is set using iwconfig.

routes and firewall seem not to be causing the issue.

wp_supplicant is installed and running.

Net_applet monitor shows the wifi dongle sending date after being manually configured, but receiving nothing back.
Before config access point visible but interface 'down'
Monitor-Before-ESSID.png (43.07 KiB) Viewed 195 times

After config access points visible but ESSID still funny
Monitor-After-ESSID.png (55 KiB) Viewed 195 times

Net_applet showing wifi is configured and working
Net_App-After-ESSID.png (135.88 KiB) Viewed 195 times

Last edited by gregM on May 31st, '19, 01:54, edited 2 times in total.
Posts: 24
Joined: Jan 16th, '18, 01:34

Re: USB WIFI Realtek 8192SU

Postby gregM » May 30th, '19, 09:12

The USB WIFI dongle/adapter plugged into my Mageia6 system worked. The odd name of the ESSID with the b in front of the name was the same but a connection was made and I could connect. Oddly the MCC setup reported a failure to connect but the Net_Applet 'Connect' function worked getting the DHCP ip and allowing network connections. Though not every time.
Mageia 6 reports using the same r8712 driver in the hardware scan output.

I also applied all the latest updates to the Mageia7 (assume it is now in line with beta3), but there was no difference made to the way the failure to connect happened.
One thing I didnt mention was the Mageia7 is a x86_64 based system and my Mageia6 is i586 style.

Mageia6 i586 Net_applet (Network Center) showing the adapter working.
net-wifi.png (77.21 KiB) Viewed 172 times
Posts: 24
Joined: Jan 16th, '18, 01:34

Re: USB WIFI Realtek 8192SU

Postby doktor5000 » May 30th, '19, 18:32

Can you add the output (copy&paste the text here, no screenshot please) as root of
Code: Select all
iw dev wlp0s26u1u2 scan

You may also try to switch from net_applet to networkmanager, see viewtopic.php?f=25&t=5782 for some hints on that.
Cauldron is not for the faint of heart!
Caution: Hot, bubbling magic inside. May explode or cook your kittens!
Disclaimer: Beware of allergic reactions in answer to unconstructive complaint-type posts
User avatar
Posts: 14933
Joined: Jun 4th, '11, 10:10
Location: Leipzig, Germany

Re: USB WIFI Realtek 8192SU

Postby gregM » May 31st, '19, 01:54

Thanks for the link to use plasma NetworkManager. That allowed the WIFI to be correctly configured.
For some reason the iw dev wlp0s26u1u2 scan failed here but iwlist s did give out put.
Here are the steps taken to resolve this problem.
Code: Select all
While still using net_applet :-
[root@homeport greg]# iw dev wlp0s26u1u2 scan
command failed: No such device (-19)

[root@homeport greg]# iwlist s
enp3s0    Interface doesn't support scanning.

wlp0s26u1u2  Scan completed :
          Cell 01 - Address: FC:75:16:7F:1B:78
                    ESSID:"lot 6"
                    Protocol:IEEE 802.11bgn
                    Frequency:2.437 GHz (Channel 6)
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
                              24 Mb/s; 36 Mb/s; 54 Mb/s; 6 Mb/s; 9 Mb/s
                              12 Mb/s; 48 Mb/s
                    IE: IEEE 802.11i/WPA2 Version 1
                        Group Cipher : CCMP
                        Pairwise Ciphers (1) : CCMP
                        Authentication Suites (1) : PSK
                    IE: Unknown: DD7B0050F204104A00011010440001011041000100103B00010310470010554783622AD20718BC222783E5B70A201021000842726F6164636F6D1023000842726F6164636F6D1024000631323334353610420004313233341054000800060050F20400011011000A42726F6164636F6D4150100800020088103C000101
                    Signal level=74/100 

Changing to plasma NetworkManager
Installed with MCC
plasma-applet-nm - NetworkManager Plasma 5 applet​
networkmanager-applet - Network connection manager system tray applet​

Disabled net_applet AutoStart
echo "AUTOSTART=FALSE" > ~/.net_applet

Setup NetworkManager by systemctl :-

[root@homeport greg]# systemctl start NetworkManager.service

[root@homeport greg]# systemctl enable NetworkManager.service
Created symlink /etc/systemd/system/multi-user.target.wants/NetworkManager.service → /usr/lib/systemd/system/NetworkManager.service.
Created symlink /etc/systemd/system/dbus-org.freedesktop.nm-dispatcher.service → /usr/lib/systemd/system/NetworkManager-dispatcher.service.
Created symlink /etc/systemd/system/network-online.target.wants/NetworkManager-wait-online.service → /usr/lib/systemd/system/NetworkManager-wait-online.service.

[root@homeport greg]# systemctl disable  NetworkManager-wait-online.service
Removed /etc/systemd/system/network-online.target.wants/NetworkManager-wait-online.service.

[root@homeport greg]# systemctl status  NetworkManager.service
● NetworkManager.service - Network Manager
   Loaded: loaded (/usr/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2019-05-31 09:02:43 AEST; 1min 29s ago
     Docs: man:NetworkManager(8)
 Main PID: 9303 (NetworkManager)
   Memory: 3.4M
   CGroup: /system.slice/NetworkManager.service
           └─9303 /usr/sbin/NetworkManager --no-daemon

May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3337] manager: NetworkManager state is now CONNECTED_SITE
May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3338] policy: set 'System enp3s0' (enp3s0) as default for IPv4 routing >
May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3720] device (enp3s0): Activation: successful, device activated.
May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3724] manager: NetworkManager state is now CONNECTED_GLOBAL
May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3751] supplicant: wpa_supplicant running
May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3751] device (wlp0s26u1u2): supplicant interface state: init -> starting
May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3870] sup-iface[0x1077810,wlp0s26u1u2]: supports 1 scan SSIDs
May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3879] device (wlp0s26u1u2): supplicant interface state: starting -> rea>
May 31 09:02:45 homeport NetworkManager[9303]: <info>  [1559257365.3880] device (wlp0s26u1u2): state change: unavailable -> disconnected (>
May 31 09:02:55 homeport NetworkManager[9303]: <info>  [1559257375.3930] manager: startup complete

After setting up NetworkManager control on the system tray, I disabled the LAN connection, and selected the WIFI device where I was asked for the WPA password, and the connection was made.

I then re-booted to ensure the changes were still in effect, and now can use the WIFI adapter on Mageia7 kernel 5.1.5-desktop-1.mga7 on i86_64 hardware.

So the problem seems to have been the net_applet configuration utility.

Thanks for the suggestions.
Posts: 24
Joined: Jan 16th, '18, 01:34

Return to Networking

Who is online

Users browsing this forum: No registered users and 1 guest