Strange Client issue

Unanswered Question
Apr 24th, 2012


We have a strange issue which only started a few weeks ago.

the hardware

wlc 5508 ver

APs - AIR-LAP1142N-N-K9  

we have AP groups setup with mobility between 3 controllers

2 dhcp servers - isc dhcp - lease time is 1 hour

The client MAC OS X 10.6.7 and there seems to be 100s of people being affected

repaired file permissions on one of the MBP - to no avail

The client has mac in sleep mode, wakes up the mac book and tries to connect, at which point the airport connects but does not get an IP.

these errors are on the increase

Client Excluded: MACAddress:x Base Radio MAC  :y Slot: 1 User Name: unknown Ip Address: unknown  Reason:Attempted to use IP Address assigned to another device.   ReasonCode: 3

if the MAC client is connected and moves to another location and another AP in the same controller

The client is excluded and blocked out.

I have disabled dhcp proxy on the controller to no avail.

I have restarted the dhcp servers

I have removed the wireless profile from the client, which helped yesterday, but the problem returned this morning.

It seems to me that the duplicate IP is the same IP of the client,

Also have a lot more of these errors

Client Excluded: MACAddress:x Base Radio MAC  :y Slot: 0 User Name: unknown Ip Address: unknown  Reason:802.11 Association failed repeatedly.  ReasonCode: 2

and when we look up clients MAC address we see that the client has both of these errors with in the same period of time.

We have some clients that are not having this problem at all.

Any thoughts or Ideas would be greatly appreciated

I have this problem too.
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Scott Fella Tue, 04/24/2012 - 19:11

What type of authentication is used? Make sure you don't have both WPA and WPA2 enabled on the same WLAN.

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Andrew MacTaggart Tue, 04/24/2012 - 19:22

ssid 1

[WPA2][Auth(PSK)] - radius with mac address filtering

ssid 2

[WPA2][Auth(802.1X)] - radius with ldap authentication

ssid 3


Scott Fella Tue, 04/24/2012 - 19:24

So which WLAN is the issue? With the radius, what details do you see on the radius logs?

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Andrew MacTaggart Tue, 04/24/2012 - 19:37

ssid 1 and 2, but mostly 1

in fact if a user never had connected to ssid 2 or 3 the connect straight away to ssid 2 or 3, but if they had connected to ssid 2 or 3, they display the same issue, client excluded.

I will contact the radius server admin and see what I can find.

In the meantime I have rebooted the dhcp servers and removed client exclusion option from controllers.

Scott Fella Tue, 04/24/2012 - 19:44

Might be how the device goes into sleep mode. I just had a customer today thy had issues when the user closes the lid and opens the lid right away. They had to adjust the power setting to get that fixed, but the clients would fail to reconnect. If removing client exclusion fixes the issue, then maybe you have to sniff the traffic and see what is being sent and what isn't being sent.


Scott Fella

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