CCNP Enterprise 300-420 Dumps PDF

Contracting an internet connection and deploying DMVPN is the most practical solution when the enterprise needs a fast, affordable, and reliable backup for a single MPLS provider. DMVPN can use broadband internet transport to build encrypted GRE/IPsec tunnels between sites, providing a backup WAN path without waiting for another private MPLS provider circuit. It supports dynamic routing and can be deployed incrementally, which makes it suitable after a recent outage when time and cost matter. BFD echo mode toward a provider PE can improve failure detection, but it does not create an alternate transport if the only MPLS provider has an outage. Adding a WAN router and a floating static route also fails unless another path exists. Contracting a second MPLS provider and deploying GETVPN may be robust, but it is slower and more expensive than the requested quick and affordable backup. Reference topics: DMVPN backup WAN, MPLS resiliency, internet VPN, IPsec, branch availability, rapid WAN deployment.

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.

An MPLS WAN from two separate ISPs is the strongest fit when the enterprise requires an active/backup WAN design with guaranteed SLAs for applications on either connection. MPLS VPN services are typically delivered with provider-backed service-level commitments for latency, jitter, packet loss, and availability, which is why they are selected for predictable enterprise application transport. Using two separate MPLS providers improves resiliency against a provider failure while preserving SLA-backed behavior on the backup path. A hybrid MPLS and Internet VPN model can be cost effective, but the Internet path generally does not provide the same deterministic SLA unless enhanced by a specific managed service contract. Internet from two providers improves reachability diversity but does not inherently guarantee application SLA. A single ISP hybrid design creates a provider dependency and weakens availability. Therefore, dual-provider MPLS is the conservative design for guaranteed active/backup WAN service. Reference topics: MPLS WAN design, service-level agreements, active/backup WAN, provider diversity, application performance assurance.

BFD is not required for the specific failure described: a physical fiber break on point-to-point routed links. In a Layer 3 campus or routed-access design, a direct physical link failure is detected by the interface state change, so the routing protocol can react immediately without waiting for hello/dead timers. Cisco campus design guidance favors point-to-point routed links partly because they give rapid convergence and avoid STP delays. BFD is valuable when a forwarding-path failure is not reliably detected by Layer 1 or Layer 2, or when a protocol adjacency must detect loss faster than its native timers. It does not automatically create convergence by itself; it detects failure and notifies the routing protocol. For a clean fiber cut on a routed point-to-point link, link-down detection is already fast enough for sub-second failover in the design. OSPF timer tuning is also not the preferred design answer for this physical-failure case. Reference topics: routed access design, point-to-point links, link-failure detection, BFD, OSPF convergence.