Has anyone seen or know of how this client-based TKIP notification manifests on
Cisco controllers?

Bruce T. Johnson | Network Engineer | Partners Healthcare 
Network Engineering | 617.726.9662 | Pager: 31633 | [EMAIL PROTECTED]



-----Original Message-----
From: The EDUCAUSE Wireless Issues Constituent Group Listserv on behalf of
Joshua Wright
Sent: Thu 12/4/2008 11:33 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Aruba ARM 2.0
 
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Kade Cole wrote:
> We have been using the 3.3.2.x code line for a while now. We have not
> enabled any of the advanced ARM 2.0 features yet. We are also
> experiencing some weird issues with Macs on the N APs. Every once in a
> while our MacBook Pros will throw up an alert that says "Your Wireless
> LAN has been compromised and will be disabled for one minute." Is this
> the same thing you are seeing?

I've seen this error a few times on TKIP networks, caused by a MIC
failure calculation on received frames.  I suspect this is a bug in the
driver's MIC code, but I haven't been able to narrow it down further.

When a client observes a MIC failure, it will send a MIC Failure
Notification message to the AP (a critical component of the new TKIP
attack, more at
http://www.willhackforsushi.com/presentations/TKIP_Attack_Webcast_2008-11-17.pdf
).
 The AP keeps track of these notices, and will shut down the network for
60 seconds if more than two are received within 60 seconds.

On ArubaOS, check the system logs for entries like the following:

Received TKIP Micheal MIC Failure Report from the Station [mac addr]
[bssid] [apnames]

This logging entry indicates the AP is indeed seeing MIC failures from
clients, supporting this theory.

If you aren't running TKIP, or have additional details you can share,
I'd love to hear them.  Thanks!

- -Josh


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