Core issue
The %AAAA-3-NOREG: authentication method 6 has no registry! error message appears when an internal software error occurs. The message appears once at bootup and every time a new user logs into the device. It is still possible to log in, but this message appears every time.
This happens when the device is configured with the aaa new-model command, but no Terminal Access Controller Access-Control System (TACACS) or
Remote Authentication Dial-In User Service (RADIUS) group is configured. It can be configured in these ways:
This error is documented in Cisco bug ID CSCse45735.
In some scenarios, traceback errors can also appear along with this error message. Sometimes, even when the aaa is configured properly, if the switch uses the backup authentication method for some reason, the error message appears. This error message is cosmetic and does not cause any other issue.
Resolution
The workaround for this issue is to remove the aaa new-model command configuration in order to stop the appearance of the message on bootup or whenever a new user logs into the device.
Configure a RADIUS or TACACS authentication group in order to prevent the appearance of the message with every new login, but note that a single message still appears on bootup.
This issue is resolved in these Cisco IOS software releases:
In order to resolve this issue, upgrade the Cisco IOS software to any one of these releases, which can be downloaded from Cisco Downloads.
