What is the main objective of the NSF feature?

The main objective of the Non-Stop Forwarding (NSF) feature is to ensure uninterrupted packet forwarding during routing protocol reconvergence or a switchover event, such as when a router's control plane fails or needs to be reloaded. With NSF enabled, a router can maintain its data forwarding capabilities using its existing forwarding information base (FIB) while a routing protocol re-establishes adjacencies and updates its routing table. This capability significantly reduces downtime and packet loss for traffic flowing through the router, thus enhancing the availability of services in a network.

In contrast to other options, which focus on different aspects of network management or functionality, B directly addresses the core purpose of NSF in maintaining service continuity during control plane disruptions. For instance, while managing routing table updates is important, it does not directly relate to the forwarding capabilities during a switchover. Similarly, security for multicast traffic and minimizing CPU usage do not encapsulate the primary function of NSF, which is centered around ensuring that IP packets are still being forwarded even as the router undergoes changes.