Cisco Cisco 2106 Wireless LAN Controller

One Time Passwords (OTP) are supported on the Wireless Lan Controller (WLC) using TACACS and 
RADIUS. In this configuration, the controller acts as a transparent pass-thru device. The controller 
forwards all client requests to the TACACS/RADIUS server without inspecting the client behavior.  
When using OTP the client must only establish a single connection to the controller to function properly.  
The controller currently does not have any intelligence or checks to correct a client that is trying to 
establish multiple connections.

In software releases prior to 6.0, the controller sends uppercase alpha characters in the MAC address. In 
software release 6.0 or later, the controller sends lowercase alpha characters in the MAC address for the 
RADIUS called-station-id and calling-station-id attributes. If you enabled these attributes for 802.1X 
authentication in previous releases and upgrade to software release 6.0, client authentication fails. 
Therefore, you must change the MAC addresses to lowercase characters on the RADIUS server before 
upgrading to software release 6.0.

You can create up to 50 access point groups for 2100 series controllers and controller network modules 
and up to 192 access point groups for 4400 series controllers, 5500 series controllers, the Cisco WiSM, 
and the 3750G wireless LAN controller switch.

You must disable IP-MAC address binding in order to use an access point in sniffer mode if the access 
point is joined to a 5500 series controller, a 2100 series controller, or a controller network module 
running software release 6.0. To disable IP-MAC address binding, enter this command using the 
controller CLI: config network ip-mac-binding disable.

WLAN 1 must be enabled in order to use an access point in sniffer mode if the access point is joined to 
a 5500 series controller, a 2100 series controller, or a controller network module running software 
release 6.0. If WLAN 1 is disabled, the access point cannot send packets.

When controllers in the mobility list are running different software releases (such as 5.0, 5.1, 5.2, and 
6.0), Layer 2 or Layer 3 client roaming is not supported between GD to ED. It is supported only between 
controllers running the same and GD release such as 6.0 and 4.2.

Guest tunneling works only between controllers running the same software release or between 
controllers running software release 4.2 and controllers running any later software release (for example, 
4.2 to 5.0, 4.2 to 5.1, 4.2 to 5.2, or 4.2 to 6.0). Guest tunneling does not work among controllers running 
other combinations of software.