Ask Klaus!

Ask Klaus!

Article from Issue 97/2008

Klaus Knopper is the creator of Knoppix and co-founder of the LinuxTag expo. He currently works as a teacher, programmer, and consultant. If you have a configuration problem, or if you just want to learn more about how Linux works, send your questions to:

Password Type


I have had my IBM ThinkPad R50e for about three years, and I have been running Ubuntu Linux on it reasonably satisfactorily. Originally, I used Ubuntu 6.06 LTS and could only get the wireless networking to work in open mode.

I now have Ubuntu 8.04 LTS installed and can use WPA2 with the password setting that my router requires. However, I have to set the network password type and password each time I switch the laptop back on. The password type has changed from WPA2 to WPA and the number of password blobs has increased from the correct 12 to more than will fit in the text box.

I attach the lspci details. The networking worked immediately, except for the annoyance of having to re-enter the password and type each session. Can you suggest anything I might do to make things better?


Please check that the password is correctly saved in /etc/wpa_supplicant/wpa_supplicant.conf, and ensure that wpa_supplicant has been automatically started once your computer boots.

The entry in wpa_supplicant.conf should be similar to Listing 1.

Listing 1


01 ctrl_interface=/var/run/wpa_supplicant
02 ap_scan=1
03 fast_reauth=1
05 network={
06     scan_ssid=1
07     # Use proto="WPA" to limit to WPA ONLY, "RSN" for WPA2
08     ssid="your_wlan_network_name"
09     psk="your_secret_wpa_password"
10 }

Some distributions set up wpa_supplicant via wpa_cli and entries in /etc/network/interfaces instead, but the basic configuration idea is the same. wpa_supplicant needs a while to authenticate, so maybe in your setup, the DHCP request just comes a little too early.

To check on the WPA status, enter the following:

$ sudo wpa_cli status

which should give an output like the following when WPA is operational and an IP address has been obtained:

Selected interface 'eth1'

Why Windows?


In the September 2008 issue, page 56, Klaus rhetorically asks why anyone would need Windows. I work for a company that uses VPN security to allow us to log in from home. This security package only runs on Windows XP (not earlier or later versions) and is called SC_XP_2k_ngxR60_hfa1.exe. Of course, this works in a virtual WinXP window, but this critical application must have Windows.

For those of us who cannot select the software packages that big organizations use, we are stuck with their choices. These choices almost always mandate Windows. In my case, it must be WinXP.


My rhetorical answer would be: "Why choose a proprietary VPN with an uncertain security level and uncertain future maintenance costs over a standardized, open source solution like OpenVPN or SSH?"

I'm not attempting to discuss whether or not SC_XP_2k_ngxR60_hfa1.exe would run under Wine, because in my opinion, it does not offer much advantage using an open source operating system just as a loader for a proprietary software base.

Of course, you are right: Often the users are simply not allowed to make a choice on their own, which is a problem that, sadly, has no technical solution.

USB Modem


I am currently running Debian 4.0 "Etch" on a home-built PC (AMD Athlon, 1GB DDR RAM). I'm trying to connect to the Internet using a USB modem (Huawei E160G) in the UK. I have managed to load the drivers for the modem using dmsg and lsusb, in conjunction with modprobe alterations. However, when it comes to configuring the modem using kppp, I need to provide usernames and passwords, which my ISP tends not to supply, therefore making it impossible to connect.

I decided to install Debian 5.0 "Lenny," which I found to be a lot better when it comes to hardware detection. Lenny sees my modem as a GSM modem, without me making any alterations. However, when I try to connect, I am faced with similar unfriendliness regarding kppp.

I know that "Lenny" sees my modem but cannot get past this problem of configuring it so that it actually works. I have followed numerous online tutorials, only to be let down. Wvdial and Gnome PPP are equally unfriendly. My whole problem is probably between the chair and keyboard.

Also, will future Knoppix distros provide support for USB modems?


Debian/Knoppix, as well as all recent GNU/Linux distributions, support USB modems. A USB serial module called USBSerial works with many devices that identify themselves as serial modems. Check with lsmod | grep usbserial for the presence of this module once the modem has been plugged in, and check dmesg | grep ttyUSB. If it doesn't appear, try modprobe usbserial as root. For your modem, the serial line autodetection seems to work, so /dev/ttyUSB0 is operational.

The E160G is an UMTS modem, which means that the connection procedure is similar to dialing a provider's number via phone line, except that some parts have to be changed in the standard setting of your modem program.

I'm describing two alternative configurations here: One is via kppp, the graphical modem tool in KDE, and the second one is a plaintext configuration of wvdial.

Don't worry about the unknown login/password for authentication. Actually, you don't need them because your modem identifies you using the SIM card number, so your Internet connection gets charged to your phone bill. But because kppp demands a login and password, you can literally give both of them as three.

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