Wireless tools for Linux
Encyclopedia
Wireless tools for Linux is a package of Linux
commands (simple text-based utilities/tools) intended to support and facilitate the configuration of wireless devices using the Linux Wireless Extension. The Wireless tools for Linux and Linux Wireless Extension are maintained by Jean Tourrilhes and sponsored by Hewlett-Packard
.
.
In many Linux distributions, this package is included by default, or based on whether a wireless card is present. If it is not automatically installed by the distribution, it is usually easy to find in binary form.
and KDE
, or an application called NetGo, to manipulate these settings.
By default, interface names are dynamic, and each network adapter
is assigned the first available name (eth0, eth1...) while the order network interfaces are created may vary. Now ifrename allows the user to decide what name a network interface will have. It can use a variety of selectors to match interface names to the network interfaces on the system, the most common selector is the interface MAC address
.
ifrename must be run before interfaces are brought up, which is why it's mostly useful in various scripts (init
, hotplug) but is seldom used directly by the user. By default it renames all present system interfaces using mappings defined in /etc/iftab.
, SSID
). It may also be used to display the wireless statistics (extracted from /proc/net/wireless).
In the free Berkeley Software Distribution
UNIX
operating systems, the role of iwconfig is performed by an expanded ifconfig
command.
Sample
The following command displays information about the currently associated wireless network.
It doesn't take any arguments.
By default it will print the ESSID of the device, and if it doesn't have any it will print its NWID instead. The information reported is the same as the one shown by iwconfig, but iwgetid is easier to integrate in various scripts.
The command is primarily used to generate a list of nearby wireless access point
s and their MAC address
es and SSIDs.
Sample
The following screen dialog shows the result of scanning for nearby wireless access points.
This scan yields only one nearby wireless access point. Helpful information in this scan includes ESSID, the type of network, and signal quality.
Without any argument, iwpriv lists the available private commands available on each interface, and the parameters that they require. Using this information, the user may apply those interface specific commands on the specified interface.
The information gathered is the same as that available in
Manpages:
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
commands (simple text-based utilities/tools) intended to support and facilitate the configuration of wireless devices using the Linux Wireless Extension. The Wireless tools for Linux and Linux Wireless Extension are maintained by Jean Tourrilhes and sponsored by Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
.
Adoption
It is included with most operating system distributions built on the Linux kernelLinux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
.
In many Linux distributions, this package is included by default, or based on whether a wireless card is present. If it is not automatically installed by the distribution, it is usually easy to find in binary form.
Frontends
Due to the relative complexity of requiring several separate commands for one task (e.g. iwlist and iwconfig to find and sync with a wireless access point), some recommend using frontends provided by GNOMEGNOME
GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...
and KDE
KDE
KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...
, or an application called NetGo, to manipulate these settings.
ifrename
ifrename allows to rename wireless network interfaces based on various static criteria to assign a consistent name to each interface.By default, interface names are dynamic, and each network adapter
Network card
A network interface controller is a computer hardware component that connects a computer to a computer network....
is assigned the first available name (eth0, eth1...) while the order network interfaces are created may vary. Now ifrename allows the user to decide what name a network interface will have. It can use a variety of selectors to match interface names to the network interfaces on the system, the most common selector is the interface MAC address
MAC address
A Media Access Control address is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used for numerous network technologies and most IEEE 802 network technologies, including Ethernet...
.
ifrename must be run before interfaces are brought up, which is why it's mostly useful in various scripts (init
Init
init is a program for Unix-based computer operating systems that spawns all other processes. It runs as a daemon and typically has PID 1. The boot loader starts the kernel and the kernel starts init...
, hotplug) but is seldom used directly by the user. By default it renames all present system interfaces using mappings defined in /etc/iftab.
iwconfig
iwconfig is used to display and change the parameters of the network interface which are specific to the wireless operation (e.g. interface name, frequencyFrequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
, SSID
Service set identifier
A service set is all the devices associated with a local or enterprise IEEE 802.11 wireless local area network .-Service set identifier :...
). It may also be used to display the wireless statistics (extracted from /proc/net/wireless).
In the free Berkeley Software Distribution
Berkeley Software Distribution
Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
UNIX
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating systems, the role of iwconfig is performed by an expanded ifconfig
Ifconfig
ifconfig is a system administration utility in Unix-like operating systems to configure, control, and query TCP/IP network interface parameters from a command line interface or in system configuration scripts...
command.
Sample iwconfig output
The following command displays information about the currently associated wireless network.
$ iwconfig eth1
eth1 IEEE 802.11g ESSID:"OSU_PUB"
Mode:Managed Frequency:2.427 GHz Access Point: 00:0D:9D:C6:38:2D
Bit Rate=48 Mb/s Tx-Power=20 dBm Sensitivity=8/0
Retry limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=91/100 Signal level=-39 dBm Noise level=-87 dBm
Rx invalid nwid:0 Rx invalid crypt:860 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:39 Missed beacon:8
iwevent
iwevent displays wireless events generated by drivers and setting changes that are received through the RTNetlink socket. Each line displays the specific wireless event which describes what has happened on the specified wireless interface.It doesn't take any arguments.
iwgetid
iwgetid reports the ESSID, NWID or access point/cell address of the wireless network that is currently used.By default it will print the ESSID of the device, and if it doesn't have any it will print its NWID instead. The information reported is the same as the one shown by iwconfig, but iwgetid is easier to integrate in various scripts.
iwlist
iwlist is used to scan for available wireless networks and display additional information about them that is not displayed by iwconfig. The main argument is used to select a category of information, iwlist displays in detailed form all information related to this category, including information already shown by iwconfig.The command is primarily used to generate a list of nearby wireless access point
Wireless access point
In computer networking, a wireless access point is a device that allows wireless devices to connect to a wired network using Wi-Fi, Bluetooth or related standards...
s and their MAC address
MAC address
A Media Access Control address is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used for numerous network technologies and most IEEE 802 network technologies, including Ethernet...
es and SSIDs.
Sample iwlist output
The following screen dialog shows the result of scanning for nearby wireless access points.
$ iwlist eth1 scan
eth1 Scan completed :
Cell 01 - Address: 00:12:17:46:E6:AF
ESSID:"shutyourstupiddogup"
Protocol:IEEE 802.11bg
Mode:Master
Channel:1
Encryption key:off
Bit RateBit rateIn telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....
:1 Mb/s
Bit Rate:2 Mb/s
Bit Rate:5.5 Mb/s
Bit Rate:6 Mb/s
Bit Rate:9 Mb/s
Bit Rate:11 Mb/s
Bit Rate:12 Mb/s
Bit Rate:18 Mb/s
Bit Rate:24 Mb/s
Bit Rate:36 Mb/s
Bit Rate:48 Mb/s
Bit Rate:54 Mb/s
Quality=82/100 Signal level=-48 dBm
Extra: Last beacon: 36ms agoThis scan yields only one nearby wireless access point. Helpful information in this scan includes ESSID, the type of network, and signal quality.
iwpriv
It is used to manipulate parameters and setting of the Wireless Extension specific to each driver (as opposed to iwconfig which deals with generic ones).Without any argument, iwpriv lists the available private commands available on each interface, and the parameters that they require. Using this information, the user may apply those interface specific commands on the specified interface.
iwspy
iwspy is used to monitor a set list of nodes and record the link quality of each of them.The information gathered is the same as that available in
/proc/net/wireless: quality of the link, signal strength and noise level. This information is updated each time a new packet is received, so each address of the list adds some overhead in the driver. Note that this functionality works only for nodes part of the current wireless cell, you can not monitor access points you are not associated with (you can use Scanning for that) and nodes in other cells. In Managed mode, in most case packets are relayed by the access point, in this case you will get the signal strength of the access point. For those reasons this functionality is mostly useful in ad hoc and master mode.See also
- NdisWrapperNdisWrapperNDISwrapper, is a free software driver wrapper that enables the use of Windows XP drivers for network devices , on Linux only operating systems. NDISwrapper works by implementing the Windows kernel and NDIS APIs, and dynamically linking the Windows drivers to this implementation...
- NetworkManagerNetworkManagerNetwork Manager is a software utility aimed at simplifying the use of computer networks on Linux-based and other Unix-like operating systems.- Overview :...
- Linux Wireless (Security) Tools
External links
Manpages: