300-420 Exam Dumps : Designing Cisco Enterprise Networks (ENSLD) v1.1

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.

The valid get-config reply must show OSPF process ID 400 with network 192.168.128.128/25 enabled for Area 0. A /25 prefix has a block size of 128 addresses, so 192.168.128.128/25 is a valid network boundary and covers addresses from 192.168.128.128 through 192.168.128.255. Any reply that shows the wrong OSPF process, an incorrect network boundary, the wrong prefix length or wildcard equivalent, or a nonzero area does not verify the requested model set. In Cisco IOS XE model-driven configuration, the readback has to match the schema path and values used by the model, not simply produce an approximate CLI interpretation. Option B is the reply that confirms the intended OSPF object. This verification method is important because YANG automation can fail silently in operational workflows when the payload is syntactically valid but targets the wrong container or key. A get-config verification step confirms the running datastore contains the exact OSPF process and area membership required by the design. Reference topics: YANG OSPF configuration, NETCONF get-config, prefix validation, IOS XE native models.

Secure segmentation is the Cisco SD-WAN Secure Direct Cloud Access function that separates user traffic into different zones and VPNs or VRFs. In Cisco SD-WAN, VPNs provide logical segmentation that is comparable to VRF separation in traditional routing. Secure Direct Cloud Access extends this segmentation model when users access internet and cloud applications directly from the branch. The design can keep corporate, guest, payment, voice, IoT, and other traffic classes isolated, with policy and security controls applied per segment or zone. Centralized data policy controls forwarding behavior, but the feature that divides traffic into separate zones and VPN or VRF contexts is secure segmentation. Perimeter control and application-aware routing are useful security and performance functions, but they do not describe the core segmentation mechanism. Segmentation is a fundamental SD-WAN design requirement because direct cloud access must not collapse trust boundaries simply because traffic no longer hairpins through a central data center. Reference topics: Cisco SD-WAN secure segmentation, VPNs, VRFs, direct cloud access, zone-based policy.