You have just increased the MTU size of interface ge-0/0/0 and committed the configuration.
Which command would help you identify the applied MTU change?
Correct Answer:
D
After increasing the MTU size of an interface and committing the configuration, the command to verify the applied MTU change is D, "show interfaces ge- 0/0/0." This command displays detailed information about the interface, including the current MTU size, making it the best choice for verifying the applied changes.
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?
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.
After the factory default configuration is loaded, which configuration object must be created prior to the first commit?
Correct Answer:
A
In Juniper Networks devices, when the factory default configuration is loaded, the first step before committing any configuration is to set up root authentication. This is crucial because it secures the device by ensuring that only authorized users have administrative access. Without setting up a root password, the device will not allow any commit operations, which is a safety measure to prevent unauthorized access. This requirement emphasizes the importance Juniper places on security right from the initial setup of the device.
Which two statements are true about the Junos OS? (Choose two.)
Correct Answer:
AC
In Junos OS, as with many network operating systems, the control plane is responsible for processes that determine how to route traffic. This includes maintaining routing tables, which store information about network paths and protocols. Therefore, routing tables are indeed stored in the control plane.
Exception traffic refers to packets that cannot be processed by the normal fast-path processing of the Packet Forwarding Engine (PFE) in the forwarding plane, and thus are sent to the control plane for further processing. This might include packets destined for the router itself, packets that need to be fragmented, or packets that match certain firewall filter criteria, among other reasons.
Routing tables are not stored in the forwarding plane. However, the forwarding plane contains the forwarding table (sometimes referred to as the forwarding information base or FIB), which is a distilled version of the routing table optimized for fast packet forwarding. The forwarding plane uses this information to perform the actual transfer of packets across the network device interfaces.
When considering routing tables and forwarding tables, which two statements are correct? (Choose two.)
Correct Answer:
AD
The routing table and forwarding table play distinct roles in a Junos OS device. The correct answers are A and D. The routing table (A) is used by the Routing Engine (RE) to select the best route among all the learned routes, while the routing table (D) stores all routes and prefixes learned from all routing protocols. The forwarding table, in contrast, contains only the active routes chosen by the RE and is used by the Packet Forwarding Engine for actual packet forwarding.