Showing results for 
Search instead for 
Did you mean: 

AP or RADIuS Server disconnects Wireless Users constantly



We are working with an Autenthication Server with Wireless Network, the AP´s are located on diferent LAN´s, but the problem is that some users get disconnection constantly, while anothers users are working without problems, same AP or diferent, you can be working without problems, but sometimes this problem can be in your PC.

Do you know, what i need to check ? do you have any idea about it?

Thank you, regards.

9 Replies 9


I would strongly advise you to try to find a constant in your troubleshooting, be it a specific wlan client radio, a specific vlan, our perhaps a group policy on the radius server. Your approach can aid you greatly in eliminating possible culprits if your approach is effective, else you find yourself covering the same ground and making no headway toward resolve. This could be something as simple as an "idle-timeout" setting in radius (seems like it would impact all clients, but not all clients are logging in at the same time or staying on continuously)...there is a variable that you've yet to discover that could be a one-stop solution to your problem. Based on the limited info in your post, it would be mile-long checklist to troubleshoot, but you can do so if you look, as mentioned before, for a constant. Wish I could help more!


Are any of your clients using Intel Wireless Network cards.

We have had an issue with laptops equiped with INTEL cards constantly disconnecting from the Access Points while others stay connected.

As far as I know there is no solution as yet (I believe it is an incompatibility issue with some Windows dll files)


Some cards are Intel, Dell and Cisco, i´m going to check that point, but you are right, some cards constantly disconnecting from the AP´s while others stay connected.

I don´t know if this problem is with AP´s Configuration, RADIUS Server, or Windows.

What version of ACS r u running? What are the logs from the AP's saying? What version of code on the AP's? Need some more info to help


I´m having problems yet, with Intel Cards, did you find any solution ?

Thank you, Luis.

I am experiencing the same problem. Some clients will work all day while others are continuously being disconnected.

ACS version 4.0 and WLC version

The logs just say the client disassociated reason unknown.

We have the same issue WLC v3.2.116.21. Some work fine, others are continuously disconnected. It depends on which AP they are near. We are seeing the issue with Intel 2200 b/g cards and Symbol 802.11b handheld scanner with 802.1X EAP-PEAP authentication. We have a P2 open with TAC now and have sent them wireless traces.

We did not see the issue with v3.2.78.0 but TAC told us they would not support issues after the roll back. Here is their quote: "Cisco does not support software downgrade for WLC. If you downgrade a WLC from to, you may run into problem[s]. We do not test software downgrade[s] for [the] WLC. Thus, a software downgrade is not supported."

I have been able to resolve this issue in our network today. Turns out that I had setup ACS with a DHCP scope that was conflicting with the windows domain DHCP.

Clients logging on were being assigned addresses by ACS that were already being used by access points. The WLC was kicking these connections.

After an authentication attempt, check your WLC logs for duplicate address -type errors. These also define the MAC addresses of the conflicting hosts.

Hope this helps!



When I was having disconnecting issue with our WLAN, and PEAP WinXP clients. I applied MS Hot Fix KB885453. It helped me.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Recognize Your Peers