Wireless

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Revision as of 04:44, 19 September 2017 by Paul Blankenbaker (talk | contribs) (Configuring WIFI from the command line)
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What Wireless Cards Are Supported?

Unfortunately, getting a wireless card to work with Linux, can be quite tricky. Often, it comes down to searching the Internet, making your best guess from bits of information, and then purchasing a card and trying it. It doesn't help that manufacturers like to change chip sets without changing model numbers.

The following lists the manufacturers of WIFI card chip sets that we have had good luck with working out of the box.

See the "Linux wireless LAN support" web site to access a WIFI compatibility database.

How Do I Get My Broadcom Card Working?

Since the NST system is based off of Fedora, it comes with a kernel module that can be used to support some Broadcom WIFI cards. The kernel module is named: b43. Unfortunately, it appears that the required firmware for this module is not provided by Fedora.

Instructions and more information on dealing with Broadcom cards can be found on the "b43 and b43legacy" page at the Linux Wireless web site.

How do I determine the manufacturer of the chip set in my WIFI card?

The lspci command is useful in determining who manufacturers the WIFI chip set in your WIFI adapter and what version of the chip set is used. For example:

[root@cayenne ~]# lspci | grep -i network
02:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01)
[root@cayenne ~]# 

The output of the above command suggests that the WIFI card is manufactured by Atheros Communications Inc. and that it has a model number of AR9285. This card happens to work well in a NST system, however if it didn't, a Google search on "Atheros AR9285 Fedora" would likely provide some clues as to what would need to be done to make it work.

Will My Wireless Card Work At Boot?

It is unlikely that when you boot a live NST system that it will use your wireless card at boot as the default network device. In order for this to occur during a Console mode boot, all of the following must be true:

  • The NST system must recognize and support your WIFI card.
  • The NST system must associate the eth0 interface with your WIFI card (it typically won't do this if your system has any Ethernet devices).
  • There must be a wireless access point within range that has no authentication/encryption in place.

However, if you boot a live NST system to Desktop mode instead of Console mode, the NetworkManager service will be running. The NetworkManager service tries very hard to determine and establish a connection to networks. If there is a open wireless access point within range of your system, its possible that your NST system will connect to it automatically when you log in.


How Do I Configure My Wireless Card For Network Access?

From The GNOME Desktop

If you plan on using your WIFI card as your connection to the network, it is recommended to boot your NST system to Desktop mode, log into the system using the GNOME desktop manager and use the NetworkManager applet. There will be a network icon on the top bar of your desktop you click on to work with the applet. The NetworkManager applet makes it very easy to connect to different WIFI networks and to enter in the necessary key(s) to join encrypted networks.

From The NST WUI

If you are not running the NetworkManager service, you can use the NST WUI to setup a secure WPA connection. From the top menu bar on the NST WUI, select: Network|Wireless|WPA-PSK Setup. This should open up a page in the NST WUI which allows you to select which interface to configure, to scan for available networks and to enter your pre-shared key.

WIFI From The Command Line (with NetworkManager)

If you are using NetworkManager to manage your wireless interface, you can use the nmcli (NetworkManager Command Line utility) to connect your wireless card to an access point. It works as follows:

  • Scan your system for WIFI cards
  • Scan for access points
  • Connect to the access point
[root@chimi ~]# nmcli device wifi rescan
[root@chimi ~]# nmcli device wifi list
*  SSID                             MODE   CHAN  RATE       SIGNAL  BARS  SECURITY  
   ringo-2.4                        Infra  9     54 Mbit/s  100     ▂▄▆█  WPA2      
*  ringo-5.0                        Infra  153   54 Mbit/s  100     ▂▄▆█  WPA2      
   --                               Infra  9     54 Mbit/s  67      ▂▄▆_  WPA2      
   HP-Print-88-ENVY 4500 series     Infra  3     54 Mbit/s  52      ▂▄__  WPA2      
   NETGEAR58                        Infra  10    54 Mbit/s  42      ▂▄__  WPA2      
   ATT8u3W7d9                       Infra  6     54 Mbit/s  40      ▂▄__  WPA1 WPA2 
   belkin.d43.guests                Infra  11    54 Mbit/s  30      ▂___  --        
   belkin.d43                       Infra  11    54 Mbit/s  30      ▂___  WPA1 WPA2 
   ATT9Zug2Nn                       Infra  4     54 Mbit/s  29      ▂___  WPA2      
   2WIRE201                         Infra  9     54 Mbit/s  29      ▂___  WPA1 WPA2 
   MotoVAP_M91427SA0MS8             Infra  108   54 Mbit/s  29      ▂___  WPA2      
   ATT2IAK24t_guest                 Infra  8     54 Mbit/s  25      ▂___  WPA2      
   HP-Print-5A-Deskjet 2540 series  Infra  3     54 Mbit/s  24      ▂___  WPA2      
   NETGEAR58-5G                     Infra  153   54 Mbit/s  19      ▂___  WPA2      
[root@chimi ~]# nmcli device wifi connect ringo-5.0 password WIFI_PASSWORD
Device 'wlp3s0' successfully activated with 'ff3fee57-dbb1-4c04-854a-ee3a3c4f9b75'.
[root@chimi ~]# 



WEP From The Command Line (no NetworkManager)

We do not recommend using WEP for accessing WIFI networks as WEP does not provide much security. However, if you need to connect your NST system to a wireless access point using WEP, you should be able to use NetworkManager if you've logged into a GNOME desktop.

If you need to access WEP from the command line, here are some dated notes from 2005 which might prove useful:

The first problem is to determine the name of the device (eth0, eth1, wlan0, etc) which Linux associates with your wireless card. After inserting your wireless card into your system, you can use the iwconfig command to determine its device name.

[root@cayenne ~]# iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

wlan0     IEEE 802.11bgn  Mode:Managed  Access Point: Not-Associated   
          Tx-Power=20 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
         
wlan0mon  IEEE 802.11bgn  Mode:Monitor  Frequency:2.472 GHz  Tx-Power=20 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          
[root@cayenne ~]# 

The above shows that wlan0 is the device name associated with a wireless card.

Once you determine the device name of your wireless card, you will need to create the appropriate configuration file under the: "/etc/sysconfig/network-scripts" directory. The following shows how one could create the necessary configuration for the wireless card and then restart the network drivers to enable the card.

[root@probe root]# cdnet
[root@probe network-scripts]# cp nst-eth0.dhcp ifcfg-wlan0
[root@probe network-scripts]# vim ifcfg-wlan0
DEVICE=wlan0
BOOTPROTO=dhcp
ONBOOT=yes

ESSID="bogus"
MODE="Managed"
RATE="auto"



:wq
[root@probe root]# cat >| keys-wlan0
KEY="FEDCBA9876543210123456789A"
^D
[root@probe root]# chmod 600 keys-wlan0
[root@probe root]# service network restart
Shutting down interface wlan0:                             [  OK  ]
Shutting down loopback interface:                          [  OK  ]
Setting network parameters:                                [  OK  ]
Bringing up loopback interface:                            [  OK  ]
Bringing up interface wlan0:                               [  OK  ]
[root@probe root]#

For your card, you will need to change the values assigned to the ESSID and KEY variables above. You may also need to specify something other than wlan0 if the iwconfig output shows your WIFI card having a different device name.

Will My Wireless Card Work With Kismet and Airsnort?

Some wireless cards that work perfectly fine for general networking, won't work with Kismet or Airsnort. It turns out that in order for a wireless card to be used by either of these two programs, the driver for the card needs to support monitor mode. If monitor mode is not supported, then you won't be able to use programs such as Kismet or Airsnort.

The best way to determine whether your WIFI card supports monitor mode or not is to setup and try using Kismet. To do this:

  • Select Network|Wireless|Kismet Server from the NST WUI menu bar.
  • Press the Setup System To Run Kismet button.
  • Press the Return button after setup completes.
  • Press the Kismet README file to read up on the ncsource configuration line.
  • Press the Edit Kismet Config button and check and/or adjust the ncsource parameter.
  • Press the Save & Return button.
  • Press the Start button to start the kismet_server service.
  • Press the Server Log button and look for ERROR messages indicating that Kismet failed to use your WIFI card or failed to put your WIFI card into monitor mode.

Note for a complete walk through on setting up Kismet, see: HowTo Geolocate kismet Data - you can ignore the steps related to setting up a GPS as you don't have to have a GPS connected to run Kismet.

Can I Monitor And Use the Wireless Card For Networking?

Typically you can not use a wireless card for both monitoring and networking at the same time. It is definitely not possible if you enable channel hopping while using the wireless card in monitor mode.