monitoring droped wlan packedge

Live forum:


28-11-2007 11:42:17


My question is
There is a chance, that I can monitoring the WLAN packedges? I have to see, how many packedges dropt by the driver, becouse of it's wrong.

How can I set to monitor mode my USB dongle, with the mac80211 wlan stack?

Can you help me?


28-11-2007 18:40:19

Check the manpage of iwconfig, and you will find

iwconfig wlan0 mode monitor

make sure to execute that command while the interface is down.


28-11-2007 21:27:41

Thank's for the help.

Can you help me about broken wireless packedge receiving?
The CRC check funkction for the wifi packedge is, in the mac80211 stack, or one of your files.

I have an USB donge. It use the rt2500 driver, and the other libs and files to use stick with the mac80211 wifi stack.


29-11-2007 19:07:55

Grab the latest rt2x00 version, and use debugfs. The latest version creates the debugfs file <debugfs root>/<mac80211 entry>/<rt2x00 entry>frame/dump

If you read that dump file, you will capture all incoming and outgoing frames regardless of any filtering in mac80211.
Mattias has created a tool that can save the frames and make them accessible for wireshark


02-12-2007 17:20:15

Thank's. It's a usefull for me, but the link is broken. (


03-12-2007 12:04:01

FYI The server is back up, so you can download the tools.

Let me know if you have any problems.


03-12-2007 15:36:58

This version only run with 2.6.24rc kernel?

I have ubuntu Gutsy generic 2.6.22 kernel, also mac80211 stack.
But the driver it not able to complaine. (


03-12-2007 20:41:21

The frame dumping facility is actually only in our git tree. It probably won't be in mainline until 2.6.25


05-12-2007 12:38:58

There is the day of the installation and probe. Atfer that, I will write the results. )

But, I would have some help to find broked wifi packet with wireshark. Can you help me?


05-12-2007 23:39:41

Wireshark will probably color packets with invalid checksums anyway, but you can also use wireshark's filtering capabilities to filter the packet list for whatever criteria you like. You'll first need to decide which frames are considered bad, then you can define an appropriate filter.