JN0-105 Exam Dumps - Juniper JNCIA Questions and Answers

Referring to the exhibit, the presence of the "+" symbol next to the OSPF route for 192.168.100.2/32 indicates that this is the active route being used to forward traffic. The BGP route, although present, does not have the "+" symbol, indicating it is not the active route. In Junos OS, the routing table displays the active route with a "+" symbol, and the fact that the OSPF route has this symbol means it is the preferred path based on the routing protocol's decision process, which takes into account factors such as route preference (administrative distance) and metrics.

Two physical interface properties in Junos OS include the MAC address (A) and the Maximum Transmission Unit (MTU) size (D). The MAC address is a hardware identifier for the network interface, while the MTU size determines the largest packet size that the interface can transmit without needing to fragment the packet.

In Junos OS, the archival configuration under [edit system] allows for the automatic backup of configuration files to designated locations upon commit. When multiple archive-sites are specified, as shown in the exhibit with both SCP and FTP sites listed, the device does not choose between them or use them in a round-robin manner. Instead, it attempts to transfer the configuration backup files to all specified sites simultaneously upon each commit. This ensures redundancy and increases the likelihood that a backup will be successfully stored even if one of the transfer methods or destinations fails.

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.

The show chassis hardware command in Junos OS displays detailed information about the hardware installed in the device, including the chassis itself. This command provides a list of all hardware components, their serial numbers, part numbers, and version information. When looking for the chassis serial number specifically, this command is the most direct and comprehensive way to retrieve that information, as it includes the serial number of the chassis among the details provided.

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.

The show | compare command in Junos OS is used to display the differences between the candidate configuration and the active configuration. If no output is shown when you issue this command, it means that there are no changes between the candidate configuration and the active configuration. This indicates that the candidate configuration is identical to the active configuration, and thus no differences are displayed.

In the Junos OS, multiple software processes run independently in their own protected memory spaces. This design ensures that if one process crashes or encounters an issue, it does not affect the other processes running on the system. This architecture enhances the stability and reliability of the network device, as each process operates independently and securely.

Traceoptions in Junos OS are used for detailed debugging and troubleshooting of protocols and processes within the system. They are not enabled by default due to the potential performance impact and volume of data generated. Instead, traceoptions are enabled through specific configuration settings under the relevant protocol or process hierarchy. This allows administrators to target their troubleshooting efforts and control the scope of logging. By default, the output generated by traceoptions is stored in files located in the /var/log directory, with the file name typically specified in the traceoptions configuration. This structured approach to logging and debugging helps in diagnosing complex issues without overwhelming the system or the administrator with irrelevant data.

In the context of VLANs (Virtual Local Area Networks) on a Juniper switch, the numerical values assigned to each VLAN, such as those for Prod, Test, and Dev, are known as VLAN tags. These tags are part of the 802.1Q VLAN standard, which allows multiple VLANs to coexist on a single physical network. Each tag uniquely identifies the VLAN to which a frame belongs, enabling the switch to segregate and manage traffic based on VLAN membership. This tagging mechanism allows for efficient traffic separation and management, ensuring that devices within one VLAN do not receive traffic intended for another, thus maintaining network security and efficiency.