sta = dev[0].own_addr()
filt = "wlan.fc.type == 2 && " + \
"wlan.da == " + sta + " && " + \
- "wlan.sa == " + ap
+ "wlan.sa == " + ap + " && " + \
+ "wlan.fc.protected == 1"
fields = ["wlan.ccmp.extiv"]
res = run_tshark(capfile, filt, fields)
vals = res.splitlines()