CCNP Enterprise 300-420 Exam Dumps

GETVPN is the correct transport-encryption design for this environment. The company is using a private MPLS-based service and requires encryption without maintaining permanent point-to-point tunnels. GETVPN was designed for private WAN environments where routing remains native and packets are encrypted without adding GRE or IPsec tunnel overlays between every pair of sites. It uses group-based keying, typically with key servers that distribute security policy and rekey material to group members. That supports dynamic key rotation and spoke-to-spoke communication while avoiding the operational burden of building and maintaining individual tunnels. DMVPN also supports dynamic spoke-to-spoke tunnels, but it is still a tunnel overlay using mGRE, NHRP, and IPsec, and it is usually selected for Internet or mixed transport overlays. Standard IPsec VPN requires maintaining tunnel relationships, and GRE VPN alone does not provide encryption. GETVPN therefore best matches tunnel-less encryption across a private MPLS WAN with centralized security policy and direct site-to-site forwarding. Reference topics: GETVPN, group encrypted transport, tunnel-less IPsec, private MPLS WAN encryption, group keying.

A totally stubby OSPF area is the best choice for a small remote site with low-end routers and no requirement to carry transit traffic. A standard stub area blocks Type 5 external LSAs, but it still receives interarea Type 3 summary LSAs. A totally stubby area goes further by blocking external routes and most interarea summary routes, while allowing a default route to be injected by the ABR. That greatly reduces LSDB size, SPF processing, memory use, and routing-table entries on the low-end routers. The remote site still has full connectivity to the rest of the OSPF domain through the default route. NSSA and totally NSSA designs are useful when the area must inject external routes from an ASBR inside the area, but the question does not state that the remote site needs redistribution. A regular stub area is acceptable but does not minimize resources as much as a totally stubby area. Because there is no demand for traffic to pass through this area, the most efficient Cisco design is totally stubby. Reference topics: OSPF stub areas, totally stubby area, default routing, LSDB reduction, branch OSPF design.

Cisco Express Forwarding uses the adjacency table to store the Layer 2 rewrite information needed to forward packets efficiently. CEF separates forwarding decisions into the Forwarding Information Base and the adjacency table. The FIB identifies the best next hop based on routing information, while the adjacency table contains the directly connected next-hop details, including the MAC address and encapsulation rewrite string used on the outgoing interface. That is why the correct layer is Layer 2. CEF is not using the adjacency table to populate Layer 3 routes; the routing table and FIB handle Layer 3 reachability. It is also not a Layer 1 function because physical signaling does not determine the next-hop rewrite. Layer 4 is unrelated to CEF adjacency resolution. In a campus or WAN design, CEF matters because it allows hardware or optimized software forwarding without process-switching every packet. Correct ARP, neighbor discovery, and adjacency formation are therefore essential to fast packet forwarding, especially when convergence or high-throughput forwarding is required.

Running BFD between EIGRP neighbors is the appropriate design when the problem is traffic loss during link failure and the requirement is to reduce the impact of the failure. EIGRP can detect neighbor loss through its hello and hold timers, but those timers may not be fast enough for applications sensitive to packet loss. Bidirectional Forwarding Detection provides rapid failure detection independent of the routing protocol’s normal timer expiration. When BFD detects a failed forwarding path, it notifies EIGRP so the routing process can converge without waiting for the EIGRP hold timer. Summarization is still a valuable scaling technique, but it primarily reduces route table size and query scope; it does not directly accelerate failure detection on an individual inter-router link. Reducing EIGRP hello and hold timers can improve detection, but it increases control-plane load and is less efficient than BFD. The question emphasizes data loss when any one link fails, so fast failure detection is the best corrective design. Reference topics: EIGRP convergence, BFD, failure detection, hello and hold timers, routed-link resiliency.