Cisco Cisco IOS Software Release 12.4(6)T

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The MSCHAP Version 2 feature (introduced in Cisco IOS Release 12.2(2)XB5) allows Cisco routers to 
utilize Microsoft Challenge Handshake Authentication Protocol Version 2 (MSCHAP V2) 
authentication for PPP connections between a computer using a Microsoft Windows operating system 
and a network access server (NAS).

For Cisco IOS Release 12.4(6)T, MSCHAP V2 now supports a new feature: AAA Support for 
MSCHAPv2 Password Aging. Prior to Cisco IOS Release 12.4(6)T, when Password Authentication 
Protocol (PAP)-based clients sent username and password values to the authentication, authorization, 
and accounting (AAA) subsystem, AAA generated an authentication request to the RADIUS server. If 
the password expired, the RADIUS server replied with an authentication failure message. The reason for 
the authentication failure was not passed back to AAA subsystem; thus, users were denied access 
because of authentication failure but were not informed why they were denied access. 

The Password Aging feature, available in Cisco IOS Release 12.4(6)T, notifies crypto-based clients that 
the password has expired and provides a generic way for the user to change the password. The Password 
Aging feature supports only crypto-based clients.

Your Cisco IOS software release may not support all of the features documented in this module. To reach 
links to specific feature documentation in this module and to see a list of the releases in which each feature is 
supported, use the 

.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image 
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