Cisco Cisco 2106 Wireless LAN Controller

This section describes important information about the controllers and access points.

In controller software release 4.2.61.0, the controller’s bootup configuration file is stored in an 
Extensible Markup Language (XML) format rather than in binary format. When you upgrade a controller 
from a previous software release to 4.2.61.0, the binary configuration file is migrated and converted to 
XML. However, the configuration file does not migrate correctly if it contains any of the following 
characters as part of a user configuration string: &, <, >, ', ". For example, a WLAN profile named R&D 
causes an XML parsing error after the second reboot, even though this profile name is valid in 4.1 and 
previous configurations.

When clients use the controller’s internal DHCP server, IP addresses are not preserved across reboots. 
As a result, multiple clients can be assigned the same IP address. To resolve any IP address conflicts, 
clients must release their existing IP address and request a new one.

The controller supports web authentication redirects only to HTTP (HTTP over TCP) servers. It does not 
support web authentication redirects to HTTPS (HTTP over SSL) servers.

The controller disables the radio bands that are not permitted by the configured country of operation 
(CSCsi48220).

Cisco recommends that you do not configure 40-MHz channels in the 2.4-GHz radio band because 
severe co-channel interference is likely to occur.

In controller software release 4.2 or later, external antenna gain is factored into the maximum transmit 
power of the access point. Therefore, when you upgrade from an earlier software release to 4.2 or later, 
you might see a decrease in transmit power output.