Use airodump-ng and Horst to analyze the live WiFi traffic:
airodump-ng wlan0
#figure out BSSID, SID, connected stations, etc.
airodump-ng --band abg wlan0
#figure out BSSID, SID, connected stations, etc on all bands (default only 2.4).
airodump-ng --channel 3 wlan0
#sniffing on channel 3
airodump-ng --channel 3 --essid WHATSOVER wlan0
#sniffing on channel 3 filtering by essid
airodump-ng --channel 3 --encrypt WPA1 wlan0
#sniffing on channel 3 only for encryption WPA1
Home of the WiFi tools: