ISIS supports both plain text and cryptographic authentication. However, only one
authentication scheme can be configured at a time:
Configure plain text authentication using the
Configure cryptographic authentication using the
command for MD5, SHA, or other authentication schemes.
The following behavioral change was introduced that impacts the ISIS authentication
Starting with Release 16.10.1, the
command can be used to enable cryptographic authentication. Therefore, plain
text authentication cannot be configured using the
command if the
command is already configured.
After Release 16.10.1, you are no longer required to issue the authentication mode
command. Enter the
command to configure cryptography. This command cannot co-exist with the
command. As a result of the new behavior, you will see the following error
message when you attempt to configure authentication in combination with the
Enter configuration commands, one per line. End with CNTL/Z.
Device(config)#router isis abc
Device(config-router)#authentication key-chain isis-key
%Please configure password using authentication command
Since the new software does not allow configuration of the
command to coexist with the
command, the behavior change will cause a service interruption when a device is
upgraded. This command will be automatically deleted from the new configuration.