wlanctl

Examine the IEEE 802.11 wireless LAN client/peer table

Syntax:

wlanctl interface [...]

wlanctl -a

Runs on:

QNX Neutrino

Options:

-a
Display the nodes for all interfaces.

Description:

Use the wlanctl utility to print node tables from IEEE 802.11 interfaces. Use the -a flag to print the nodes for all interfaces, or list one or more 802.11 interfaces to select their tables for examination. For example, to examine the node tables for atw0, use:

wlanctl atw0

The wlanctl utility displays the node table. For example:

atw0: mac 00:02:6f:20:f6:2e bss 02:02:6f:20:f6:2e
        node flags 0001<bss>
        ess <netbsd>
        chan 11 freq 2462MHz flags 00a0<cck,2.4GHz>
        capabilities 0022<ibss,short preamble>
        beacon-interval 100 TU tsft 18425852102545544165 us
        rates [1.0] 2.0 5.5 11.0
        assoc-id 0 assoc-failed 0 inactivity 0s
        rssi 161 txseq 10 rxseq 1420
atw0: mac 00:02:2d:2e:3c:f4 bss 02:02:6f:20:f6:2e
        node flags 0000
        ess <netbsd>
        chan 11 freq 2462MHz flags 00a0<cck,2.4GHz>
        capabilities 0002<ibss>
        beacon-interval 100 TU tsft 18425852105450086784 us
        rates [1.0] 2.0 5.5 11.0
        assoc-id 0 assoc-failed 0 inactivity 0s
        rssi 159 txseq 2 rxseq 551
atw0: mac 00:02:6f:20:f6:2e bss 02:02:6f:20:f6:2e
        node flags 0000
        ess <netbsd>
        chan 11 freq 2462MHz flags 00a0<cck,2.4GHz>
        capabilities 0022<ibss,short preamble>
        beacon-interval 100 TU tsft 18425852102558548069 us
        rates [1.0] 2.0 5.5 6.0 9.0 11.0 12.0 18.0 24.0 36.0 48.0 54.0
        assoc-id 0 assoc-failed 0 inactivity 145s
        rssi 163 txseq 9 rxseq 2563

This example is taken from a network consisting of three stations running in ad hoc mode. The key for interpreting the node printouts follows:

mac
In the sample node table, the first network node has MAC number 00:02:6f:20:f6:2e.
bss
The first node belongs to the 802.11 network identified by Basic Service Set Identifier (BSSID) 02:02:6f:20:f6:2e.
node flags
Only one node flag, bss, is presently defined. The first node is distinguished from the rest by its node flags: flag bss indicates that the node represents the 802.11 network that the interface has joined or created. The MAC number for the node is the same as the MAC number for the interface.
ess
The name of the (Extended) Service Set we have joined. This is the same as the network name set by ifconfig with the ssid option.
chan
The wlanctl utility prints the channel number, the center frequency in megahertz, and the channel flags. The channel flags indicate the frequency band ( (2.4GHz or 5GHz), modulation (cck, gfsk, ofdm, turbo, and dynamic cck-ofdm), and operation constraints (passive scan). Common combinations of band and modulation are:
Band Modulation Description
2.4GHz cck 11Mb/s DSSS 802.11b
2.4GHz gfsk 1-2Mb/s FHSS 802.11
2.4GHz ofdm 54Mb/s 802.11g
2.4GHz dynamic cck-ofdm Mixed 802.11b/g network
5GHz ofdm 54Mb/s 802.11a
5GHz turbo 108Mb/s 802.11a
capabilities
Ad hoc-mode and AP-mode 802.11 stations advertise their capabilities in 802.11 Beacons and Probe Responses. The wlanctl utility understands these capability flags:
Flag Description
ess Infrastructure (access point) network
ibss Ad hoc network (no access point)
privacy WEP encryption
short preamble Reduce 802.11b overhead
pbcc 22Mbps 802.11b+
channel agility Change channel for licensed services
beacon-interval
In the example, beacons are sent once every 100 Time Units. A Time Unit (TU) is 1024 microseconds (a "kilo-microsecond" or kus). Thus 100 TU is about one tenth of a second.
tsft
802.11 stations keep a Time Synchronization Function Timer (TSFT) which counts up in microseconds. Ad hoc-mode stations synchronize time with their peers. Infrastructure-mode stations synchronize time with their access point. Power-saving stations wake and sleep at intervals measured by the TSF Timer. The TSF Timer has a role in the coalescence of 802.11 ad hoc networks ("IBSS merges").
rates
802.11 stations indicate the bit-rates they support, in units of 100KB/s in 802.11 Beacons, Probe Responses, and Association Requests. The wlanctl utility prints a station's supported bit-rates in 1Mb/s units. A station's basic rates are flagged by an asterisk (*). The last bit-rate at which a packet was sent to the station is enclosed by square brackets.
assoc-id
In an infrastructure network, the access point assigns to each client an Association Identifier, which is used to indicate traffic for power-saving stations.
assoc-failed
The number of times the station tried and failed to associate with its access point.
inactivity
The number of seconds that elapsed since a packet was last received from the station. When this value reaches net.link.ieee80211.maxinact, the station is eligible to be purged from the node table.
rssi
Unitless Received Signal Strength Indication (RSSI). Higher numbers indicate stronger signals. Zero is the lowest possible RSSI. On a hostap- or adhoc-mode interface, the node with node flag bss set uses rssi to indicate the signal strength for the last packet received from a station that doesn't belong to the network. On an infrastructure-mode station, the node with node flag bss set indicates the strength of packets from the access point.
txseq
The next 802.11 packet sent to this station will carry this transmit sequence number. The 802.11 MAC uses the transmit sequence number to detect duplicate packets.
rxseq
The last packet received from this station carried this transmit sequence number.