Cisco Cisco IOS Software Release 12.2(55)SE

Support for increasing the NVRAM buffer size for saving large configuration files. 

ARP tracking probe enhancement to specify a source IP address for a VLAN.

Network Edge Access Topology (NEAT) controls the supplicant port during the supplicant 
authentication period. When you connect a supplicant switch to the authenticator switch, the 
authenticator port could be error-disabled when receiving Spanning Tree Protocol (STP) bridge 
protocol data unit  (BPDU) packets and the supplicant switch is not authenticated. The NEAT feature 
is now enhanced to block the supplicant port during authentication, to ensure authentication 
completes. 

Use the dot1x supplicant controlled transient global configuration command to control access to 
the supplicant port during authentication. Use the no form of this command to provide access to the 
supplicant port during the authentication period

You should review this section before you begin working with the switch. These are known limitations 
that will not be fixed, and there is not always a workaround. Some features might not work as 
documented, and some features could be affected by recent changes to the switch hardware or software.