Which two fields are you required to enter when you create a new user account? (Choose two.)

1. A. username
2. B. full name
3. C. user ID
4. D. login class

Correct Answer: AD
In Junos OS, when creating a new user account, the minimum required fields are the username and the login class. The username is the identifier for the account, while the login class specifies the level of access or permissions the user has on the device. Login classes allow for the differentiation between various roles, such as read-only access or full administrative rights. Other information, such as full name or user ID, is optional and not strictly necessary for the creation of a functional user account.

Which command modifier would you use to see all possible completions for a specific command?

1. A. |
2. B. detail
3. C. ?
4. D. extensive

Correct Answer: C
In Junos OS, the ? command modifier is used to display all possible completions for a specific command. This helps users understand the available options and syntax for a command they are trying to use.
Reference: Juniper Networks CLI Documentation
"Use the ? command modifier to display all possible completions for a specific command."

What is a benefit of using J-Web?

1. A. It simultaneously manages multiple devices.
2. B. It provides a customizable dashboard.
3. C. It provides more advanced features than the CLI.
4. D. It provides console-based management.

Correct Answer: B
If you've committed a configuration and then need to revert to the previous configuration, the rollback command is used. Since the incorrect IP address has not been committed, as indicated by the commit check command being successful, issuing rollback 1 will undo the changes made in the current session, which includes the accidental entry of the IP address.

Which Junos OS component is responsible for maintaining the forwarding table?

1. A. Routing Engine
2. B. chassis control daemon
3. C. Packet Forwarding Engine
4. D. management daemon

Correct Answer: C
The Packet Forwarding Engine (PFE) in Junos OS is responsible for maintaining the forwarding table. The PFE processes incoming packets, performs route lookups in the forwarding table, and forwards packets based on this information, offloading these tasks from the Routing Engine to ensure efficient packet forwarding.

You have configured some interfaces on a Junos device; however, you have not yet committed the configuration.
What happens if you issue the rollback 0 command in this scenario?

1. A. The messages.log file is deleted.
2. B. The factory default configuration is loaded.
3. C. The Junos device is rebooted.
4. D. The interface changes you made are discarded.

Correct Answer: D
Issuing the rollback 0 command in Junos OS will discard any uncommitted changes and revert to the last committed configuration. This command effectively cancels any configuration changes that have been made but not yet committed, ensuring that the device returns to its previous stable state.
References:
✑ "rollback 0 ...................................(rolls back the changes just made )" from Useful Juniper Commands.txt.
✑ Juniper official documentation: Rolling Back a Configuration.