Display wireless events generated by drivers and setting changes
iwevent
iwevent 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.
This command doesn't take any arguments.
There are two classes of Wireless Events.
The first class is events related to a change of wireless settings on the interface (typically done through iwconfig or a script calling iwconfig). Only settings that could result in a disruption of connectivity are reported. The events currently reported are changing one of the following setting :
Network ID
ESSID
Frequency
Mode
Encryption
All those events will be generated on all wireless interfaces by the kernel wireless subsystem (but only if the driver has been converted to the new driver API).
The second class of events are events generated by the hardware, when something happens or a task has been finished. Those events include :
New Access Point/Cell address
The interface has joined a new Access Point or Ad-Hoc Cell, or lost its association with it. This is the same address that is reported by iwconfig.
Scan request completed
A scanning request has been completed, results of the scan are available (see iwlist).
Tx packet dropped
A packet directed at this address has been dropped because the interface believes this node doesn't answer anymore (usually maximum of MAC level retry exceeded). This is usually an early indication that the node may have left the cell or gone out of range, but it may be due to fading or excessive contention.
Custom driver event
Event specific to the driver. Please check the driver documentation.
Registered node
The interface has successfully registered a new wireless client/peer. Will be generated mostly when the interface acts as an Access Point (mode Master).
Expired node
The registration of the client/peer on this interface has expired. Will be generated mostly when the interface acts as an Access Point (mode Master).
Spy threshold crossed
The signal strength for one of the addresses in the spy list went under the low threshold or went above the high threshold.
Most wireless drivers generate only a subset of those events, not all of them, the exact list depends on the specific hardware/driver combination. Please refer to driver documentation for details on when they are generated, and use iwlist(8) to check what the driver supports.
Jean Tourrilhes - [email protected]