Search Linux Wireless

Re: Strange problem with ath9k and ASUS N66U AP.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

On 04/24/2012 11:08 PM, Jouni Malinen wrote:
On Tue, Apr 24, 2012 at 05:26:07PM -0700, Ben Greear wrote:
On 04/24/2012 03:50 PM, Ben Greear wrote:
I am trying some ath9k virtual clients against an ASUS N66U.

Here is part of the N66U wifi log showing that it
thinks sta11 is not authorized:

00:95:95:00:00:0C  associated
00:95:95:00:00:0D  associated authorized

Here's a better log.  Makes me think supplicant might be at fault???

Looks more like an AP bug to me..

sta8 failed, sta9 works fine.  The difference appears to be the extra
RX EAPOL packet that sta8 receives...

1335313181.999422: sta8: WPA: RX message 3 of 4-Way Handshake from c8:60:00:e8:88:b0 (ver=2)
1335313181.999465: sta8: WPA: Sending EAPOL-Key 4/4

1335313182.063695: sta8: WPA: RX message 3 of 4-Way Handshake from c8:60:00:e8:88:b0 (ver=2)
1335313182.063745: sta8: WPA: Sending EAPOL-Key 4/4

Either the AP did not receive the first EAPOL-Key 4/4 or processed it
only after retransmitting 3/4. Supplicant side will need to to reply to
retransmitted 3/4 to complete the 4-way handshake. If the AP received
either of these 4/4 messages, it should be fine with the result. If it
didn't receive either, it should disconnect the station. It does not
look like either of those happened.

Ok, it seems strange they would have such a lame
bug, but maybe they never tried associating several stations at once.
(I see around 30% failure rate when using just 15 stations).

We have several off-the-shelf APs and home-grown ones (using ath9k) that work fine,
even when associating 100+ stations, so at the least the N66U is weird...

That said, I'll probably need to attempt a work-around for this.  The only
obvious thing I see is the extra RX EAPOL (in all error cases I looked at, and none
where it associated properly), and the fact that DHCP just fails to acquire a lease.

I'll try adding a hack to detect the duplicate RX EAPOL and bounce the connection
if that hits, and see if that helps any...


Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at

[Linux Kernel]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Share Photos]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Photo]     [Yosemite]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]     [Free Dating]     [M2M Wireless]

Add to Google Powered by Linux