The relationship between the routing table (Routing Information Base or RIB) and the forwarding table (Forwarding Information Base or FIB) is the cornerstone of the Junos OS architectural separation between the control and data planes. The routing table resides in the control plane on the Routing Engine (RE). Its primary role is to aggregate all reachability information from every configured protocol and select the best route for each destination prefix based on criteria like preference and metrics.
Once the Routing Engine has identified the single " active " best path for a destination, it distills this complex routing data into a simplified, streamlined version called the forwarding table . The forwarding table contains only the essential information needed to move a packet: the destination prefix, the egress interface, and the Layer 2 next-hop MAC address. The RE then " pushes " this forwarding table to the Packet Forwarding Engine (PFE) in the data plane. By having the PFE use a table built from the routing table , Junos ensures that transit traffic can be processed at wire speed without the overhead of complex routing logic. This one-way flow-from the comprehensive RIB on the RE to the optimized FIB on the PFE-allows the device to maintain high performance even while routing protocols are recalculating or the management plane is under heavy load.

Junos OS utilizes a Role-Based Access Control (RBAC) model through the use of login classes, which define the specific permissions and restrictions for different user levels. To simplify administration, Juniper provides several predefined classes that cater to common organizational roles. The requirement here is for an account that can perform basic network diagnostics (operational mode) but lacks the authority to modify the system state (configuration mode).
The operator class is specifically engineered for this purpose. It grants permissions such as clear, network, reset, trace, and view. These permissions allow the user to execute monitoring commands like show, use diagnostic tools like ping and traceroute, and clear statistics. Crucially, the operator class does not include the configure or commit permissions, preventing the user from entering configuration mode or making any permanent changes to the device.
Comparing this to other options: the read-only class is more restrictive, generally allowing only the viewing of configuration and some state data, but often restricting active diagnostic tools like ping. The super-user class provides unrestricted access, while maintenance is not a standard predefined class for general operational roles. Assigning the operator class ensures that junior staff or automated monitoring systems have the visibility they need to troubleshoot connectivity without risking the integrity of the device configuration.
Reference: User Interfaces, Login Classes, and User Permissions.

A /26 subnet provides 64 total IP addresses, with 62 usable host addresses, which satisfies the requirement to support at least 50 hosts.

The routing table in the control plane evaluates available routes and selects the best path. The forwarding table is then derived from this selected routing information and used by the forwarding plane to make packet forwarding decisions.

Junos OS supports several methods for automatically archiving configurations upon commit. The supported methods are:
A). SCP (Secure Copy Protocol): SCP is a secure method for transferring files, including configurations, between devices. It is supported by Junos OS for archiving configurations after each commit.
C). FTP (File Transfer Protocol): FTP can also be used for transferring and archiving files, including configurations, after a commit in Junos OS.