300-420 Exam Dumps - Cisco CCNP Enterprise Questions and Answers

The correct IS-IS design combines tuned SPF/PRC behavior with a proper Level 1 and Level 2 hierarchy. Reducing SPF and PRC intervals, within platform and stability limits, helps routers react more quickly to topology changes after a link failure. However, fast timers alone are not enough; the hierarchy must contain instability so physical link flaps in the access layer have limited impact on the rest of the network. Access routers should form Level 1 adjacencies inside their local area, while aggregation routers should operate as Level 1/Level 2 routers to connect the access area to the Level 2 backbone. This design gives access routers a simple local view and uses aggregation as the interarea boundary. Running all access and aggregation routers as L1/L2 across the network increases the size of the backbone and exposes more routers to wider flooding, which is the opposite of the requirement. Redistributing Internet routes into Level 1 is also poor design because it bloats the access area. Therefore, the right choices are C and E. Reference topics: IS-IS hierarchy, L1/L2 design, SPF and PRC tuning, access-layer convergence, fault containment.

For model-driven telemetry with periodic updates, the architect must understand that each periodic update sends the subscribed data at the configured interval. Cisco telemetry guidance distinguishes periodic subscriptions from on-change subscriptions. A periodic subscription streams a full copy of the subscribed data element or table at each interval, even if the underlying state has not changed. That behavior is useful when the collector needs regular time-series samples, trending, or baseline monitoring, but it creates predictable bandwidth and collector-load requirements. On-change subscriptions are different: they publish updates when the subscribed state changes and are more efficient for state changes such as interface status, memory thresholds, or protocol adjacency m ovement. Empty subscription behavior and initial update timing may matter in specific implementations, but they are not the main design consideration in this question. Since the customer requires periodic updates, the design must size the transport, collector, retention system, and subscription intervals around repeated full data delivery. Reference topics: model-driven telemetry, periodic subscription, on-change subscription, YANG-modeled operational data, collector sizing.

DMVPN is the correct overlay VPN solution for dynamic, secure, scalable branch-to-branch communication. Cisco Dynamic Multipoint VPN uses multipoint GRE, NHRP, and IPsec to support dynamic tunnel creation without manually defining a static tunnel between every branch pair. That design is well suited to a global organization where branches communicate frequently and more branches will be added later. DMVPN allows spokes to register with hubs and, depending on the phase design, establish dynamic spoke-to-spoke tunnels for direct traffic while maintaining encrypted protection with IPsec. EasyVPN is more oriented to remote-access or simplified client/server VPN deployments and is not the scalable branch mesh solution described. GETVPN is strong for private WAN encryption but does not build dynamic IPsec tunnels over an overlay in the same manner and assumes a trusted private routing core. L2TP is not the correct enterprise dynamic branch overlay. The architect should choose DMVPN and select the appropriate phase, routing protocol, summarization strategy, and IPsec profile based on branch scale and resource limits. Reference topics: DMVPN, NHRP, mGRE, IPsec protection, spoke-to-spoke dynamic tunnels.

The selected configuration sets are correct because the addressing plan must use VLSM to maximize subnets and minimize wasted addresses. Customer A requires 125 hosts, so it needs a /25 subnet, which provides 126 usable host addresses. Customer D requires 62 hosts, so it needs a /26 subnet, which provides 62 usable addresses exactly. Point-to-point or small WAN links B, C, and E should use the smallest appropriate link subnets shown in the exhibit, typically /30 for IPv4 point-to-point links when two usable addresses are required. A correct plan must allocate the largest blocks first, align every subnet on the proper boundary, avoid overlap, and avoid assigning a larger-than-needed subnet to any customer or link. Options A and C are the two valid combinations that satisfy those rules in the exhibit. Any option that places a /25 or /26 on the wrong boundary, overlaps with another block, or wastes larger subnets on links would fail the design objective. Reference topics: IPv4 VLSM, subnet boundary alignment, host capacity planning, point-to-point addressing, route summarization readiness.

Bootstrap Router is the standards-based mechanism that supports dynamic RP discovery in a PIM sparse-mode domain. Cisco documentation distinguishes Auto-RP, which is Cisco-proprietary, from BSR, which is defined for standards-based RP distribution. With BSR, candidate RPs advertise their availability, and the elected bootstrap router distributes RP-set information throughout the PIM domain. This removes the operational burden of manually configuring the same static RP information on every multicast router. Anycast-RP provides RP redundancy and load sharing but does not by itself provide standards-based dynamic RP discovery across the domain. Static RP is simple but not dynamic. Auto-RP can dynamically distribute RP information, but it is not the standards-based answer. The design value of BSR is most visible in large multicast domains, where routers need consistent RP information and manual changes are risky. Therefore, when the question asks for a standards-based RP deployment that supports dynamic RP discovery, the correct answer is bootstrap router. Reference topics: PIM sparse mode, Bootstrap Router, candidate RP, RP-set distribution, dynamic RP discovery.

The telemetry mapping separates dial-in and dial-out behavior. In dial-in telemetry, the collector initiates the session toward the network device and subscribes to the data that it wants streamed. This model gives the collector direct control over the subscription lifecycle, but it requires the collector to reach the device and manage each session. In dial-out telemetry, the network device initiates the session toward the collector based on a configured subscription. This is useful when devices must stream telemetry to a centralized destination through firewalls or controlled management paths. Cisco model-driven telemetry can stream structured data from YANG models using subscription behavior rather than relying on repeated CLI polling. The selected drag-and-drop answer matches each consideration to the mode that owns the connection initiation and subscription handling. In design work, the architect must consider reachability direction, security policy, NAT traversal, collector scale, subscription persistence, and whether subscriptions should be configured on the device or created by the collector. Reference topics: model-driven telemetry, dial-in mode, dial-out mode, YANG subscriptions, gRPC telemetry, operational data streaming.

Cisco SD-WAN is the correct solution when the design must use internet circuits at each site while providing failover, load sharing, and QoS. Basic IPsec tunnels can encrypt traffic, but they do not by themselves provide a complete WAN architecture for path measurement, dynamic traffic steering, centralized policy, application-aware routing, or scalable operational control. Cisco SD-WAN builds secure overlay tunnels across available transports and continuously measures path characteristics such as loss, latency, and jitter. It can then steer applications according to SLA policy, use multiple circuits for active/active forwarding, and fail traffic over when a path degrades or fails. QoS can be applied consistently through templates and policy across the WAN Edge routers. GET VPN is best suited to private MPLS-style networks and does not address internet-circuit overlay orchestration in the same way. Traditional DMVPN is a valid dynamic VPN technology, but SD-WAN is the more complete resilient internet-WAN design for these requirements. Reference topics: Cisco SD-WAN, internet transport, application-aware routing, failover, load sharing, QoS.

The required resource is the organization name. During manual WAN Edge onboarding, the device needs local system identity information and transport reachability so it can authenticate into the Cisco Catalyst SD-WAN overlay. Cisco onboarding workflows identify system parameters such as system IP, site ID, organization name, and vBond information as required configuration elements. The organization name must match the value configured across the SD-WAN controllers; otherwise, certificate validation and control connection establishment fail. After the WAN Edge authenticates with vBond, vBond helps it discover the vSmart controllers and vManage. That is why the vSmart hostname is not the first required onboarding resource in this question. NAT may exist in the path and vBond can assist traversal, but NAT itself is not the configuration identity item. A generic domain name is not the same as the SD-WAN organization name. Reference topics: Cisco SD-WAN onboarding, vBond orchestrator, organization-name, control connections, WAN Edge manual configuration.

A Cisco native YANG model is the right choice when the engineer needs to configure a capability that is specific to Cisco NX-OS. YANG models fall broadly into open standards-based models and vendor-native models. IETF and OpenConfig models are useful for multivendor consistency, but they intentionally model common behavior and may not cover every platform-specific feature. Cisco native models are generated to represent Cisco operating system configuration and operational data more closely, including features that are unique to IOS XE, IOS XR, or NX-OS. Cisco developer guidance commonly positions native models as the model family to use when full platform feature coverage is required. IEEE is not the relevant model family for Cisco NX-OS feature-specific configuration in NETCONF. OpenConfig is useful when the design objective is common cross-vendor abstraction, but that is not the question’s requirement. Therefore, for an NX-OS-only feature that must be configured through NETCONF/YANG, the engineer should choose the Cisco native model for NX-OS.

Interdomain multicast designs commonly use MP-BGP and MSDP together. MP-BGP carries multicast routing information between domains so routers can perform RPF checks based on the correct multicast topology rather than relying only on unicast routing. MSDP is used between rendezvous points in different PIM sparse-mode domains to exchange information about active sources. Cisco multicast documentation describes MSDP as a mechanism that connects multiple PIM-SM domains and allows RPs to discover multicast sources in other domains. Together, MP-BGP provides the reachability information and MSDP provides source discovery between RPs. IGMPv2 is a host-to-router group membership protocol inside a local subnet, not an interdomain multicast routing protocol. MLD provides the IPv6 equivalent of host group membership signaling. BIDIR-PIM is a multicast forwarding mode optimized for many-to-many traffic inside a domain, but it is not the pair of protocols used for interdomain source and receiver communication in this question. Therefore, the correct protocols are MP-BGP and MSDP.