Difference between revisions of "Wireless Networking"


From Knoppix Documentation Wiki
Jump to: navigation, search
(Wireless Networking Overview)
m (General Information On Wireless Card Setup Under Knoppix)
Line 26: Line 26:
  
 
This is a stub for this section, to be added shortly
 
This is a stub for this section, to be added shortly
 +
 +
  
 
'''The below sections are specific information on specific make and models of Wireless Networking Adapters and  information we currently have on if they are supported in Knoppix or not. Please add your results with your card to the list, and please try to keep the list in alphabetical order.'''
 
'''The below sections are specific information on specific make and models of Wireless Networking Adapters and  information we currently have on if they are supported in Knoppix or not. Please add your results with your card to the list, and please try to keep the list in alphabetical order.'''

Revision as of 23:26, 5 September 2005

Wireless Networking Overview

Wireless networking (or wifi) allows you to network computers and related equipment (print servers, cameras, and other devices that connect by ethernet) without the need to run wires between equipment.

The advantages: Greater flexability in equipment location, no need to run network cable throughout your building, ease of moving equipment, easy and clean to add new users (such as at a wifi enabled "Hot Spot" coffe shop or airport terminal). The disadvantages: extra cost, slower speed than wired connections, connections are usually not as reliable, interference from other equipment including cordless phones and microwave ovens, security issues, extra compexity in setting the wireless network up, extra power usage in a noteboot (usually significantly reducing battery life per charge), and manufacturers usually not releasing open source drivers for Linux or even specs for the wireless chips that would allow developers to write free high quality drivers.

There are many versions of wifi equipment available. Common versions are 802.11b, a standard that runs at 11mbit/second and 802.11g, which runs at 54mb/s. 802.11g equipment can also work with 802.11b, although when you mix them the entire network often slows to the 802.11b speed. Both 802.11b and 802.11g equipment works on the unlicensed 2.4 ghz band, a band that is frequently used by cordless phones, and is close in frequency to the frequency of microwave ovens. There is another standard, 802.11a, that uses a different (higher) frequenct band. 802.11a equipment is not usually fond in the home consumer market. There are also many newer proposed standards, with many manufacturers offering faster next generation equipment even before these standards are finalized. here are also other wirelsss technologies used for other things, such as Bluetooth and wireless mice and keyboards, which are beyond the scope of this wiki article.

The range of wifi connections varys greatly with the equipment used and the location, but is typically 50 to 100 feet. It is greater outdoors than is a building with many walls or transmitting through floors. Even minor changes in transmitter and/or receiver location can significantly affect reception. Frequently users in apartment complexes will find that they can receive signals from other users wifi users, or that their own signals can be received by others. It may be ncessary to make setting in the wifi equipment to move a user to a different channel to avoid some interference.

Wifi equipment uses the same band but not the exact same channels in different countries. If you travel with wireless equipment you may still be able to connect to connect to wifi equipment when outside your country, but you should check that your equipment is not operating on channels that are illegal to use in that country.

802.11b tends to be less expensive than 802.11g. It is slower, but at 11 mb/s it is still fater than the internet connection of most users, so if you plan on using wireless networking mainly for Internet access this may be a non-issue. Older 802.11b equipment is also usually much better supported in Linux than 802.11g, when it is supported at all.

To set up a wireless network you need a wireless network interface adapter (NIC) for each computer that will not have a wired ethernet connection. You should expect to also need a wireless router that the wireless computers will all connect to and that will connect to your Internet modem. There are devices called "access points" that can be attached to an existing network that includes one or more routers, but an access point without a router is not enough. The internet modem must support an ethernet connection to attach to a router. You can not attach a Internet modem with a cheap USB only connection to a router. Home routers, even wireless routers, have dropped greatly in price recently and are now very affordable.

Linux Wireless Network Issues

This is a stub for this section, to be added shortly

Wireless Networking Security Issues

This is a stub for this section, to be added shortly

General Information On Wireless Card Setup Under Knoppix

This is a stub for this section, to be added shortly


The below sections are specific information on specific make and models of Wireless Networking Adapters and information we currently have on if they are supported in Knoppix or not. Please add your results with your card to the list, and please try to keep the list in alphabetical order.

Netgear WG111

Configuring the WG111 to use WPA-PSK on a wireless network

This card works very well in Knoppix 3.9, but is as of yet untested in other versions (to my knowledge).

  • Commands:

Assuming that the drivers are on the cd in /dev/cdrom, then

mount /dev/cdrom/ /mnt/cdrom/

Find ndiswrapper configuration under Knoppix->Network/Internet and select netwg111.inf from /mnt/cdrom. After that finishes, create the configuration file that you will need shortly using the following command:

wpa_passphrase MySSIDHere MyPassphraseHere > /home/knoppix/wpa_supplicant.conf 

Now, use your favorite text editor (if you don't have one, try Kate under the menu item Editors) and edit the /home/knoppix/wpa_supplicant.conf you just created (see sample below).

With that completed, run the following command. Warning: As it is, the command will monopolize your current command window with potentially useful debugging output, including your encryption key; add -B if you would rather run it in the background (useful when you know it works already), remove -K to hide your key.

sudo wpa_supplicant -ddKt -i wlan0 -c /home/knoppix/wpa_supplicant.conf -Dndiswrapper

The following grabs an IP address if you use DHCP from your router.

sudo pump -i wlan0

And finally, tell Knoppix where to go to find the internet.

sudo route add default gw <Gateway/Router IP address here> 
  • wpa_supplicant.conf

Note: the bold lines were added in the editing steps for my Linksys WRT54G Router to accept the card. See the Useful Links at the end for a full explanation of all options that can be put in here.

ctrl_interface=/home/knoppix/wpa_supplicant
eapol_version=1
ap_scan=1
network={
ssid="MySSIDHere"
scan_ssid=1
#psk="MyPassphraseHere"
psk=hex representation of the passphrase
proto=WPA
key_mgmt=WPA-PSK
pairwise=TKIP
group=TKIP
}
  • Useful Links:

Wireless card success story (where I located the pump command)

Example wpa_supplicant.conf with full explanations and various configurations


-bobeltomate