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

A migration from traditional IP-VPN service to Cisco SD-WAN commonly increases security and scalability. Cisco SD-WAN builds encrypted data-plane tunnels across supported transports, so the enterprise can use Internet, MPLS, or hybrid connectivity while maintaining secure site-to-site communication. The architecture also scales better operationally because policy, templates, onboarding, and routing control are centralized through the SD-WAN controllers and management plane. Increased solution complexity is not a desired characteristic; one of the design goals is to simplify operations through automation and centralized policy. Centralized application policies are also a major SD-WAN benefit, but when only two choices are selected, the stored answer emphasizes the two broad migration outcomes of security and scale. Distributed control plane is not correct because Cisco SD-WAN uses centralized control-plane logic with vSmart controllers distributing OMP routes and policies. A professional migration plan should validate transport diversity, controller redundancy, encryption policy, application-aware routing, and operational readiness. Reference topics: Cisco SD-WAN migration, encrypted overlay, scalability, centralized control plane, IP-VPN replacement.

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.

Advertising more-specific prefixes toward the preferred service provider is the correct way to influence inbound traffic to enter through a chosen CE interface. BGP inbound path control is indirect: the enterprise cannot set local preference inside remote autonomous systems, and MED is honored only under specific provider policies. The most deterministic option available to the customer is to advertise a longer-prefix route to the preferred provider because Internet and BGP route selection generally prefer the longest matching prefix before BGP path attributes are considered. If the aggregate is advertised to both providers but a more-specific route is advertised to the provider connected to gig0/0, return traffic for that more- specific destination is attracted through that interface. Lowering MED toward the less preferred provider is the opposite of the desired effect. AS-path prepending toward the preferred provider would make that path less attractive. Local preference affects outbound path selection inside the local AS, not inbound traffic from external networks. Reference topics: BGP inbound traffic engineering, longest-prefix match, route aggregation, AS-path prepending, MED, local preference.