8 Linux Commands: To Find Out Wireless Network Speed, Signal Strength And Other Information

Posted on in Categories Linux, Linux desktop, Linux laptop last updated June 6, 2012

Linux operating systems comes with various set of tools allowing you to manipulate the Wireless Extensions and monitor wireless networks. This is a list of tools used for wireless network monitoring tools that can be used from your laptop or desktop system to find out network speed, bit rate, signal quality/strength, and much more.

#1: Find out your wireless card chipset information

Type the following command to list installed wireless card, enter:
$ lspci
$ lspci | grep -i wireless
$ lspci | egrep -i --color 'wifi|wlan|wireless'

Sample outputs:

0c:00.0 Network controller: Intel Corporation Ultimate N WiFi Link 5300

Please note down the 0c:00.0.

#2: Find out wireless card driver information

Type the following command to get information about wireless card driver, enter:
$ lspci -vv -s 0c:00.0
Sample outputs:

0c:00.0 Network controller: Intel Corporation Ultimate N WiFi Link 5300
	Subsystem: Intel Corporation Device 1121
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- SERR- 
	Kernel driver in use: iwlwifi

#3: Disabling wireless networking ( Wi-Fi )

You may want to disable Wi-Fi on all laptops as it poses a serious security risk to sensitive or classified systems and networks. You can easily disable Wi-Fi under Linux using the techniques described in this tutorial.

#4: Configure a wireless network interface

iwconfig command is similar to ifconfig command, but is dedicated to the Linux wireless interfaces. It is used to manipulate the basic wireless parameters such as ssid, mode, channel, bit rates, encryption key, power and much more. To display information about wlan0 wireless interface, enter:

iwconfig Interface-Name-Here
iwconfig wlan0

Sample outputs:

wlan0     IEEE 802.11abgn  ESSID:"nixcraft5g"  
          Mode:Managed  Frequency:5.18 GHz  Access Point: 74:44:44:44:57:FC   
          Bit Rate=6 Mb/s   Tx-Power=15 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=41/70  Signal level=-69 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:28   Missed beacon:0

In the above output iwconfig command shows lots of information:

  1. The name of the MAC protocol used
  2. ESSID (Network Name)
  3. The NWID
  4. The frequency (or channel)
  5. The sensitivity
  6. The mode of operation
  7. Access Point address
  8. The bit-rate
  9. The RTS threshold
  10. The fragmentation threshold
  11. The encryption key
  12. The power management settings

How do I find out link quality?

You can get overall quality of the link. This may be based on the level of contention or interference, the bit or frame error rate, how good the received signal is, some timing synchronisation, or other hardware metric.
# iwconfig wlan0 | grep -i --color quality
Sample outputs:

Link Quality=41/70  Signal level=-69 dBm

41/70 is is an aggregate value, and depends totally on the driver and hardware.

How do I find out signal level?

To find out received signal strength (RSSI – how strong the received signal is). This may be arbitrary units or dBm, iwconfig uses driver meta information to interpret the raw value given by /proc/net/wireless and display the proper unit or maximum value (using 8 bit arithmetic). In Ad-Hoc mode, this may be undefined and you should use the iwspy command.
# iwconfig wlan0 | grep -i --color signal
Sample outputs:

Link Quality=41/70  Signal level=-69 dBm

Some parameters are only displayed in short/abbreviated form (such as encryption). You need to use the iwlist command to get all the details.

#5: See link quality continuously on screen

You can use /proc/net/wireless file. The iwconfig will also display its content as described above.

cat /proc/net/wireless

Better use the watch (gnuwatch, bsdwatch) command to run cat command repeatedly, displaying wireless signal on screen:

watch -n 1 cat /proc/net/wireless

Sample outputs:

Linux watch wireless signal
Fig.01: Linux watch wireless signal with /proc file system

Note: Again values will depend on the driver and the hardware specifics, so you need to refer to your driver documentation for proper interpretation of those values.

#6: Gnome NetworkManager

Gnome Network Manger
Fig:02: Gnome Network Manger

Gnome and many other Linux desktop operating system can use NetworkManager to keep an active network connection available at all times. he point of NetworkManager is to make networking configuration and setup as painless and automatic as possible. This package contains a systray applet for GNOME’s notification area but it also works for other desktop environments which provide a systray like KDE or XFCE. It displays the available networks and allows to easily switch between them. For encrypted networks it will prompt the user for the key/passphrase and it can optionally store them in the gnome-keyring.

Please note that NetworkManager is configured through graphical interfaces, which are available for both GNOME and KDE.

#7: Say hello to wavemon

wavemon is a ncurses-based monitoring application for wireless network devices. It displays continuously updated information about signal levels as well as wireless-specific and general network information. Currently, wavemon can be used for monitoring devices supported by the wireless extensions, included in kernels version 2.4 and higher. Just type the following command to see the details:
$ wavemon

wavemon - a wireless network monitor application
Fig.03: wavemon - a wireless network monitor application for Linux

#8: Other options

You can use the following tools too:

  1. Wicd which stands for Wireless Interface Connection Daemon, is an open source software utility to manage both wireless and wired networks for Linux.
  2. iwevent command displays Wireless Events received through the RTNetlink socket. Each line displays the specific Wireless Event which describes what has happened on the specified wireless interface. Sample outputs from iwevents:
    Waiting for Wireless Events from interfaces...
    07:11:57.124553   wlan0    Set Mode:Managed
    07:11:57.124621   wlan0    Set ESSID:off/any
    07:12:00.391527   wlan0    Scan request completed
    07:12:10.428741   wlan0    Scan request completed
    07:12:10.432618   wlan0    Set Mode:Managed
    07:12:10.432642   wlan0    Set ESSID:off/any
    07:12:10.432651   wlan0    Set Frequency:5.18 GHz (Channel 36)
    07:12:10.432722   wlan0    Set ESSID:"nixcraft5g"
    07:12:10.647943   wlan0    Association Response IEs:01088C129824B048606C2D1A7E081BFFFFFF00010000000000C20101000000000000000000003D16240D0000000000000000000000000000000000000000DD0
    07:12:10.648019   wlan0    New Access Point/Cell address:74:44:44:44:57:FC
    07:12:22.310182   wlan0    Scan request completed
  3. iwgetid command report ESSID, NWID or AP/Cell Address of wireless network. iwgetid is easier to integrate in various scripts. A sample output from iwgetid command:
    wlan0     ESSID:"nixcraft5g"
  4. iwlist command Get more detailed wireless information from a wireless interface. A typical usage is as follows:
    Usage: iwlist [interface] scanning [essid NNN] [last]
                  [interface] frequency 
                  [interface] channel 
                  [interface] bitrate 
                  [interface] rate 
                  [interface] encryption 
                  [interface] keys 
                  [interface] power 
                  [interface] txpower 
                  [interface] retry 
                  [interface] ap 
                  [interface] accesspoints 
                  [interface] peers 
                  [interface] event 
                  [interface] auth 
                  [interface] wpakeys 
                  [interface] genie 
                  [interface] modulation 

See also:

  • man pages iwlist, iw, iwconfig, iwgetid, iwevent, iwlist
  • Linux wireless wiki

Have a favorite wireless tool for Linux? Let’s hear about it in the comments.

30 comment

  1. Very helpful indeed! I specifically learned about wavemon for the first time — what a great little piece of software!

  2. Wireless Extenssion (WEXT) is almost absolute with latest kernels moving wireless subsystem to nl80211 interface. iw is going to be the tool onwards :)

  3. Thanks for the many tips and tools concerning wireless networking. There is only one tool among the list that I’ve not had very good success with, and that is NetworkManager. If anything at all needs to change, it seems to have difficulty with those changes. Two network management tools have fairly consistently worked for me: wicd and a command-based network manager called ceni. These two tools allow me to set up a typical environment for wired and wireless networks, but when something changes, I find these tools easily allow me to remove or alter my configuration, set something else up, and have it work. As long as I know the correct interfaces and their access characteristics, the drivers and networks are functioning properly, these tools work.

    I have found the Debian Wifi Wiki: http://wiki.debian.org/WiFi, which has links to many Wifi drivers, is very helpful for setting up wireless. Much of the information can be applied to other systems. The Arch Wiki is another good source for information about wireless and Wifi: https://wiki.archlinux.org/index.php/Wireless_Setup

    Both the Debian and Arch sites liberally reference other sources of information, so if you start at one of these two Wiki sites, you have an excellent chance of locating the information you are looking for.

  4. Great article!!! I tried wavemon and I really like it. It is a nice tool and I didn’t know about it before I read your article. Thanx

  5. Hey, what I think is really missing is a command that shows what PHY mode is currently used: B, G or N. I mean with N you can manually set 54Mbit/s, and in some cases in G you can have more than 54Mbit/s, so these numbers alone can be misleading.

  6. hi,,
    now i work in Linux system. I have two zolertia nodes and I want to know the signal strength or the signal quality between this nodes,, are there any command can help me ??

    thank you very much

  7. you might add or check for a tool called horst
    that is especially usefull if you want to debug mesh networks
    on debian : apt-get install horst should do the trick, or more usefull on your openwrt router (with at least 8mb of flash) : opkg update ; opkg install horst

  8. I just wanted to know, for example your PC is connected to a wireless dongle which is connected to a cellular network. If the link quality and signal strength are tested then does it test the quality of the link and signal between the wifi dongle and the PC or the link quality and strength between the cellular network and the wifi dongle. Please reply :)

Leave a Comment