Juniper Updated JN0-105 Exam Questions and Answers by noa

One of the key advantages of Junos OS is its ability to roll back to previous configurations. This feature allows administrators to revert to an earlier configuration state, which is invaluable for quickly recovering from configuration errors or undesired changes. Junos OS maintains an archive of previous configurations, enabling easy rollback to any saved state. Another significant advantage of Junos OS is its modular design. The operating system is structured so that different processes and services run in separate protected memory spaces, enhancing the stability and reliability of the system. If one process fails, it does not affect the others, thereby minimizing the risk of system-wide failures.

In Junos OS, to navigate from operational mode to configuration mode, you can use either the edit or configure command. Both commands move the CLI from operational mode, where you can view the state of the device, to configuration mode, where you can make changes to the device's configuration.

In Junos OS, the dedicated out-of-band management interface is typically named fxp0. This interface is used exclusively for management traffic and is physically separated from the data traffic interfaces. It allows administrators to perform management tasks even when the device is experiencing issues that affect the forwarding plane.

From the JNCIA-Junos Study Guide and Junos OS Documentation:

“The fxp0 interface is a dedicated management interface that provides out-of-band management access. It is commonly found on Juniper routers, switches, and security platforms. You assign IP addresses to this interface as you would any other, and it is often used to connect to a management network or to allow SSH, Telnet, or SNMP access.”

— Junos OS Fundamentals, Chapter: Interfaces

— Junos OS Documentation: Management Interfaces Overview

— JNCIA-Junos Exam Objective: Interface Types

Exception traffic refers to packets that the Packet Forwarding Engine (PFE) cannot process normally and must be forwarded to the Routing Engine (RE) for further processing. This includes packets destined for the router itself or packets needing special handling that the PFE cannot provide. To protect the RE from being overwhelmed by such traffic, which could potentially impact the router's control plane functions, exception traffic is rate-limited. This means that there's a threshold to how much exception traffic can be sent to the RE, ensuring that the router's critical management and control functions remain stable and responsive even during high traffic volumes or attacks.