how to get a list of the connected wifi clients in OpenWrt 10.03?

Question

Fa11enAngel · Answer 1 · 2022-09-01T09:55:22.387

In order to see associated wifi clients, even if they don't have a DHCP Client or have no ip, you have to ask the AP for associated wifi devices:

# MAC80211
iw dev wlan0 station dump

# Universal (Tested with OpenWRT 14.07 and 15.05.X)
# iwinfo must be installed first as it is optional
# opkg update && opkg install iwinfo
iwinfo wlan0/wl0/ath0 assoclist

# using hostapd
ubus call hostapd.wlan0 get_clients

# Proprietary Broadcom (wl)
wl -i wl0 assoclist
 
# Proprietary Atheros (madwifi)
wlanconfig ath0 list sta

This way you will also see the connection speed. For me this is looking like this:

# iwinfo wlan0 assoclist
12:34:56:78:9A:BC  -26 dBm / -95 dBm (SNR 69)  1930 ms ago
RX: 24.0 MBit/s, MCS 0, 20MHz                   3359 Pkts.
TX: 130.0 MBit/s, MCS 14, 20MHz, short GI       1209 Pkts.

score 16 · Accepted Answer · answered Mar 19 '11 at 21:28

16

You may use the arp-table, or DHCP-leases. Not a perfect solution, maybe it's enough?

List arp-table

arp

List DHCP-leases

cat /tmp/dhcp.leases

... and combined

for ip in $(arp | grep -v IP | awk '{print $1}'); do 
    grep $ip /tmp/dhcp.leases; 
done

answered Mar 19 '11 at 21:28

nsg

375
2
10

3

You have recent leases too, like a powered off laptop and a phone currently on another wifi network. – Dereckson Aug 04 '14 at 17:54
I still have empty response cat /tmp/dhcp.leases, while many devices got IP and network settings from WIFI of OpenWRT. – Boris Ivanov Aug 19 '17 at 18:25
This will not work if your router works as a bridge, since it doesn't offer the DHCP itself. – Raúl Salinas-Monteagudo Nov 28 '18 at 09:49

Alan42 · Answer 3 · 2018-09-20T10:29:54.140

2

Instead of cat /tmp/dhcp.leases|wc -l and arp -a, my solution is

opkg update
opkg install arp-scan
arp-scan --interface=br-lan --localnet | grep responded | awk '{print $12}'

It will return the number of devices which connected to OpenWRT by LAN port. Almost real time.

edited Sep 20 '18 at 10:29

answered Sep 12 '18 at 07:17

Alan42

561
4
14

score 1 · Answer 4 · answered Apr 04 '13 at 02:38

1

How about nmap?

opkg install nmap

Then do a stealth scan of your subnet (likely 192.168.1.0/24)

nmap -sS 192.168.1.0/24

This will list services running on the clients as well. It may also set off alarms if the client has port-scan detecting software (i.e snort) installed so be careful.

answered Apr 04 '13 at 02:38

KrakenSkulls

11
1

You generate traffic here. If you just want to keep statistics every minute, for example you would be creating traffing, radiation and consumption needlessly. I am thinking about the case where you want to know if your mobile phone is at your place, for a house automation system. You don't want to drain your phone battery for this. – Raúl Salinas-Monteagudo Nov 28 '18 at 09:58

kirelagin · Answer 5 · 2019-11-09T14:50:56.823

To get them directly from hostapd (the daemon that manages the access point):

$ ubus call hostapd.wlan0 get_clients

{
    "freq": 2462,
    "clients": {
        "<mac addr 1>": {
            "auth": true,
            "assoc": true,
            "authorized": true,
            "preauth": false,
            "wds": false,
            "wmm": true,
            "ht": true,
            "vht": false,
            "wps": false,
            "mfp": false,
            "rrm": [
                0,
                0,
                0,
                0,
                0
            ],
            "aid": 1
        }
    }
}

(or replace wlan0 with the interface you are interested in)

how to get a list of the connected wifi clients in OpenWrt 10.03?

5 Answers5