One command line tool that has come in quite handy many times over the years when dealing with Wi-Fi networks is ‘iw’. With this command you can scan the Wi-Fi bands for networks and get the configuration and capabilities of each in a detailed list. It’s perfect to find out, for example, which options are supported by an Access Point. Here’s an example of my 802.11ac capable access point:
The ‘highlights’ of my Access Point (AP) that are marked in blue in the output below are as follows:
- Signal strength: -65 dBm, a strong value that gives very high throughput in case there is no interference.
- The load count and utilization values are interesting as they inform clients that there are 4 devices in total connected to this access point at the moment and that the load is 6/255, i.e. not very high.
- The AP uses channel 100, i.e. in the 5 GHz band.
- The AP supports 80 MHz channels, but NOT 160 or 80+80 MHz channels.
- It supports Single-User Beamforming in both directions and and Multi-User Beamforming in downlink.
- 4×4 MIMO is supported.
sudo iw dev wlp3s0 scan BSS 00:00:00:00:00:00 (on wlp3s0) -- associated TSF: 10438666559449 usec (120d, 19:37:46) freq: 5500 beacon interval: 100 TUs capability: ESS Privacy SpectrumMgmt ShortSlotTime RadioMeasure (0x1511) signal: -65.00 dBm last seen: 304 ms ago Information elements from Probe Response frame: SSID: xxxxxxxx Supported rates: 6.0* 9.0 12.0* 18.0 24.0* 36.0 48.0 54.0 DS Parameter set: channel 100 Country: DE Environment: Indoor/Outdoor Channels [36 - 36] @ 23 dBm Channels [40 - 40] @ 23 dBm Channels [44 - 44] @ 23 dBm Channels [48 - 48] @ 23 dBm Channels [52 - 52] @ 23 dBm Channels [56 - 56] @ 23 dBm Channels [60 - 60] @ 23 dBm Channels [64 - 64] @ 23 dBm Channels [100 - 100] @ 30 dBm Channels [104 - 104] @ 30 dBm Channels [108 - 108] @ 30 dBm Channels [112 - 112] @ 30 dBm Channels [116 - 116] @ 30 dBm Channels [120 - 120] @ 30 dBm Channels [124 - 124] @ 30 dBm Channels [128 - 128] @ 30 dBm Channels [132 - 132] @ 30 dBm Channels [136 - 136] @ 30 dBm Channels [140 - 140] @ 30 dBm Power constraint: 3 dB BSS Load: * station count: 4 * channel utilisation: 9/255 * available admission capacity: 0 [*32us] HT capabilities: (MS: 802.11n) Capabilities: 0x9ef RX LDPC HT20/HT40 SM Power Save disabled RX HT20 SGI RX HT40 SGI TX STBC RX STBC 1-stream Max AMSDU length: 7935 bytes No DSSS/CCK HT40 Maximum RX AMPDU length 65535 bytes (exponent: 0x003) Minimum RX AMPDU time spacing: No restriction (0x00) HT TX/RX MCS rate indexes supported: 0-31 HT operation: * primary channel: 100 * secondary channel offset: above * STA channel width: any * RIFS: 0 * HT protection: no * non-GF present: 1 * OBSS non-GF present: 0 * dual beacon: 0 * dual CTS protection: 0 * STBC beacon: 0 * L-SIG TXOP Prot: 0 * PCO active: 0 * PCO phase: 0 Overlapping BSS scan params: * passive dwell: 20 TUs * active dwell: 10 TUs * channel width trigger scan interval: 300 s * scan passive total per channel: 200 TUs * scan active total per channel: 20 TUs * BSS width channel transition delay factor: 5 * OBSS Scan Activity Threshold: 0.25 % Extended capabilities: HT Information Exchange Supported, Extended Channel Switching, TFS, WNM-Sleep Mode, TIM Broadcast, BSS Transition, 6 VHT capabilities: (MS: 802.11ac) VHT Capabilities (0x338b79f2): Max MPDU length: 11454 Supported Channel Width: neither 160 nor 80+80 RX LDPC short GI (80 MHz) short GI (160/80+80 MHz) TX STBC SU Beamformer SU Beamformee MU Beamformer RX antenna pattern consistency TX antenna pattern consistency VHT RX MCS set: 1 streams: MCS 0-9 2 streams: MCS 0-9 3 streams: MCS 0-9 4 streams: MCS 0-9 5 streams: not supported 6 streams: not supported 7 streams: not supported 8 streams: not supported VHT RX highest supported: 0 Mbps VHT TX MCS set: 1 streams: MCS 0-9 2 streams: MCS 0-9 3 streams: MCS 0-9 4 streams: MCS 0-9 5 streams: not supported 6 streams: not supported 7 streams: not supported 8 streams: not supported VHT TX highest supported: 0 Mbps VHT operation: * channel width: 1 (80 MHz) * center freq segment 1: 106 * center freq segment 2: 0 * VHT basic MCS set: 0xfffc WMM: * Parameter version 1 * BE: CW 15-1023, AIFSN 3 * BK: CW 15-1023, AIFSN 7 * VI: CW 7-15, AIFSN 2, TXOP 3008 usec * VO: CW 3-7, AIFSN 2, TXOP 1504 usec WPS: * Version: 1.0 * Wi-Fi Protected Setup State: 2 (Configured) * Response Type: 3 (AP) * UUID: xxxxxxxxx-xxx-xx-xxxx-xxxxxxxxx * Manufacturer: AVM * Model: FBox * Model Number: 0000 * Serial Number: 0000 * Primary Device Type: 6-0050f204-1 * Device name: FBox * Config methods: Display, PBC, Keypad * RF Bands: 0x3 * Unknown TLV (0x1049, 6 bytes): 00 xx xx xx xx xx RSN: * Version: 1 * Group cipher: CCMP * Pairwise ciphers: CCMP * Authentication suites: PSK * Capabilities: 1-PTKSA-RC 1-GTKSA-RC (0x0000)
Very interesting!
i didn’t know the station count was broadcasted…
BSS Load:
* station count: 4
must have missed your post from 3yrs ago that turned up in the first places when i just tried to search for that value 😉
https://blog.wirelessmoves.com/2017/04/wifi-qbss-load-element-shows-number-of-connected-devices.html
I’m surprised my ubiquity equipment sends this information, but i’m not sure if it is correct tbh. It does not really match the number of clients that the ubnt controller shows when i look it up…️