allow and deny command attributes for user permissions

B

When creating user permissions in Junos OS, the allow and deny command attributes can be used to control which commands the user is allowed or not allowed to execute. Here are the details of each answer option:

A. If you allow and deny the same commands, the Junos OS will fail the commit check. This statement is true. If you use both allow and deny command attributes to specify the same set of commands, the Junos OS will fail the commit check because it cannot determine which action to take.

B. If you allow and deny the same commands, the allow command permissions take precedence over the deny command permissions. This statement is false. If both allow and deny command attributes are used to specify the same commands, the deny command permissions take precedence over the allow command permissions. This means that the user will not be allowed to execute the command, even if it is specified in the allow command attribute.

C. If you specify a regular expression for allow and deny with two variants of a command, both will be ignored. This statement is false. If you specify a regular expression for allow and deny with two variants of a command, the Junos OS will evaluate the regular expressions and allow or deny the commands as specified. Regular expressions are powerful tools for matching complex patterns, and they can be used to specify a range of commands with similar names.

D. The all login class permission bits take precedence over allow and deny when a user issues the rollback command. This statement is true. The all login class permission bits are a set of permissions that are granted to all users by default. These permissions take precedence over any allow or deny command attributes when a user issues the rollback command, which rolls back the configuration changes made in the current session.

In summary, the correct answer is A, and the other statements are either false or true but not relevant to the allow and deny command attributes.