I have read a lot of Q&As that have achieved success in packet captures of Wifi probe requests, which entails capturing IEEE802_11_RADIO
(802.11 plus radiotap header) in monitor mode. But I find that I cannot capture any packets at all in monitor mode (though I have no trouble with packet captures in managed mode on a network). I'm sitting right next to my iPhone, on which I am streaming video and sometimes checking for the presence of additional wireless networks.
Shouldn't I at least be picking up on beacons from APs? Can anyone suggest what my roadblock might be?
I've set my wireless card to monitor mode, then run tcpdump:
ifconfig wlan0 down
iwconfig wlan0 mode monitor
ifconfig wlan0 up
tcpdump -fni wlan0 # TCPDUMP
I've also tried using airmon-ng
to create a new device on which to attempt a capture:
stop network-manager # AIRMON-NG WARNS THAT THIS COULD CAUSE PROBLEMS IF NOT KILLED
service avahi-daemon stop # AIRMON-NG WARNS THAT THIS COULD CAUSE PROBLEMS IF NOT KILLED
killall wpa_supplicant # AIRMON-NG WARNS THAT THIS COULD CAUSE PROBLEMS IF NOT KILLED
airmon-ng start wlan0 # AIRMON-NG
tcpdump -fni mon0 # TCPDUMP
In the block of commands above, airmon-ng
outputs the following:
Interface Chipset Driver
wlan0 Unknown iwlwifi - [phy0]
(monitor mode enabled on mon0)
tcpdump
consistently outputs the following and then nothing (no captures):
tcpdump: WARNING: mon0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on mon0, link-type IEEE802_11_RADIO (802.11 plus radiotap header), capture size 65535 bytes
I'm running:
tcpdump version 4.5.1
libpcap version 1.5.3
Ubuntu 14.04 LTS
I've also tried airodump-ng
in order to scan channels 1-12.
As for my hardware, lspci
ouputs:
03:00.0 Network controller: Intel Corporation Wireless 7260 (rev 83)
Subsystem: Intel Corporation Dual Band Wireless-AC 7260
Flags: bus master, fast devsel, latency 0, IRQ 64
Memory at f0400000 (64-bit, non-prefetchable) [size=8K]
Capabilities: [c8] Power Management version 3
Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [40] Express Endpoint, MSI 00
Capabilities: [100] Advanced Error Reporting
Capabilities: [140] Device Serial Number e8-b1-fc-ff-ff-e8-fa-80
Capabilities: [14c] Latency Tolerance Reporting
Capabilities: [154] Vendor Specific Information: ID=cafe Rev=1 Len=014 <?>
Kernel driver in use: iwlwifi
802.11a/b/g/n/ac 7260ac rev. 83 man: 8086 dev:08b2 Mini-PCIe Intel iwlwifi