TL-WN722N / AR9271 generating A LOT of fake BSSIDs

[hdmn]

I have a little problem with my TP-LINK TL-WN722N (Atheros AR9271) card. It is producing a really weird output in kismet and I can't find any reason why.
It's seeing the networks around and even some, that aren't there, a lot of times with different (random) BSSIDs and sometimes slightly different SSIDs. 1000 APs in half an hour while not moving the card…
Have you seen sth like this? How can I fix this? Is it a hardware problem?!?

I verified with my Alfa - everythings normal.

And btw the WiGLE Map doesn't even show the SSIDs displayed in kismet - instead it's showing BSSIDs!?

Admins: can you please remove transaction #20150316-00079?
Thanks!
-hdmn

nearly 1000 new 'fake' AP

Screen Shot 2015-03-16 at 11.58.12.jpg (247.23 KiB) Viewed 21344 times

[hdmn]

ok... found the solution after a lot of googling...

Code: Select all

ncsource=wlan2:type=ath9k,validatefcs=true

my NIC obviously reported all frames/packets to kismet without omitting invalid or broken ones. and this is how you can tell kismet not to trust the wifi driver, but instead check them itself.

Code: Select all

validatefcs=true|false Kismet normally will not bother trying to validate the FCS checksum of incoming packets because most drivers only report valid frames in the first place. Packet sources which report invalid frames by default will enable this option automatically. If the drivers have been manually configured to report invalid packets, this should be specified to prevent Kismet from processing broken packets.

i am amazed by how much configuration options kismet is offering...
hope this helps someone else trying to figure out what's going on with their NIC.
-hdmn

[ccie4526]

Hmm, I've been running the WN722N for a while and haven't noticed any issues like this. I'll have to keep a watch on that.

Also, separately, did a bunch of sniffing around HD when I was working at the Uni-Klinikum there... about 10 years ago now.

[strasharo]

Same here, WN722N appears to produce a lot of noise by default. Thanks for the configuration tip.