Cisco 300-420 Bundle

Fabric overlay encapsulation adds overhead beyond ordinary IP reachability and depends on a healthy L3 underlay. “Provide resilient IP underlay reachability and adequate end-to-end MTU for supported fabric encapsulation” would remedy that alternative situation, but it would not correct the present issue: ordinary underlay reachability does not assign endpoint onboarding and VXLAN edge functions to a nonfabric access device.

“Design overlay forwarding paths with validated VXLAN reachability, fabric edge encapsulation and proper transport MTU” is the supported response when a fabric control plane supplies locator information, while the data plane uses supported VXLAN encapsulation to carry endpoint traffic. Here the decisive response is “Provision eligible access devices as supported fabric edge nodes and verify host onboarding and virtual network assignments”, so that different intervention does not meet the stated requirement.

Fabric control-plane endpoint-to-location mapping must reflect movement and be consistent with current host registration. “Use supported redundant LISP control-plane nodes and verify endpoint registration and mapping refresh behavior” applies to that other condition. The reported evidence is a newly connected access switch is routed to the fabric core but attached endpoints never receive the expected overlay segmentation because the device is not operating as a fabric edge; this alternative would address the wrong dependency.

That change concerns BGP local preference primary egress, where AS-path prepending mainly affects remote path selection; outbound path preference within the local AS is commonly controlled with local preference. The reported issue instead stems from: iBGP typically preserves the external next hop, which must be reachable through the internal routing infrastructure.

That change concerns BGP route reflector cluster design, where Conventional iBGP full mesh grows quadratically and becomes costly to configure, observe and recover. In this question the necessary remedy is “Provide appropriate next-hop-self policy or valid internal reachability for external BGP next hops with loop-free forwarding”, which this alternative does not provide.

That change concerns BGP as path prepending inbound engineering, where Local preference is not exported between autonomous systems, so changing it cannot directly govern external networks' inbound selection. The observed condition is an edge router shares eBGP-learned routes with internal iBGP peers, but remote clients cannot resolve the unchanged external next-hop address; this mechanism addresses another problem.

Gateway role restoration depends on the selected FHRP protocol and its configured preemption settings, not priority numbers alone. “Document whether automatic takeover or stability-first non-preemption is intended for each critical VLAN” would remedy that alternative situation, but it would not correct the present issue: traditional active-standby first-hop redundancy does not by itself provide the desired per-client gateway load distribution.

“Include virtual-gateway ownership and split-brain validation in every campus distribution switch change window” is the supported response when a single physical gateway address makes host access depend on one distribution device even when a second gateway exists. Here the decisive response is “Compare first-hop load sharing and operational complexity before selecting a protocol solely for redundancy”, so that different intervention does not meet the stated requirement.

FHRP presence alone may not account for upstream path viability without appropriate object or interface tracking. “Validate gateway priority changes against real upstream failures rather than only powering off the active switch” applies to that other condition. The reported evidence is a large access VLAN needs multiple distribution gateways to forward client traffic concurrently, but the proposed HSRP design forwards all hosts through one active router; this alternative would address the wrong dependency.

Mixed or unsuitable metric styles can undermine consistent path-cost planning and overflow the intended metric range. “Govern IS-IS metric templates and perform cost-map reviews when adding high-capacity links or changing topology” would remedy that alternative situation, but it would not correct the present issue: protocol adjacency and IPv4 routes do not alone establish correct IPv6 reachability, interface addressing or address-family support.

“Rotate routing authentication keys with overlap windows and verify peer inventory during link provisioning” is the supported response when an unprotected adjacency trust boundary can admit unauthorized IS-IS control messages into a routing domain. Here the decisive response is “Test IPv4 and IPv6 reachability separately when extending a stable routing protocol deployment”, so that different intervention does not meet the stated requirement.

Unbounded EIGRP query scope and nontransit spokes can prolong active route computation across a large topology. “Validate stub declaration and query-domain boundaries for every newly onboarded nontransit branch” applies to that other condition. The reported evidence is a network has existing IS-IS IPv4 reachability and adds IPv6-only applications, but the design assumes IPv4 reachability automatically creates IPv6 forwarding information; this alternative would address the wrong dependency.

An MPLS Layer 3 VPN routes IP among separated CE networks rather than delivering a transparent Layer 2 Ethernet service. “Choose an eligible provider Layer 2 VPN or Ethernet private line design if extending a broadcast domain is genuinely required” would remedy that alternative situation, but it would not correct the present issue: ordinary port-level upgrades may not meet aggregate fiber-capacity and distance requirements when the optical transport must host many independent wavelengths.

“Design cellular failover with tested signal strength, provider diversity, data-plan capacity and selective critical traffic routing” is the supported response when mobile backup is useful only if real coverage, policy, cost and failure independence support required branch services. Here the decisive response is “Evaluate supported DWDM wavelengths, optics, optical budget, dispersion and protection channels for the transport design”, so that different intervention does not meet the stated requirement.

Multipoint Ethernet services and many independent E-Line circuits have different Layer 2 forwarding and spanning-tree implications. “Choose appropriate Metro Ethernet point-to-point or multipoint service topology with explicit VLAN and loop-avoidance design” applies to that other condition. The reported evidence is two data centers need many high-throughput channels over existing dark fiber but an architect proposes a single low-rate Ethernet handoff for each future application; this alternative would address the wrong dependency.

Logical transport labels or TLOCs do not inherently represent independent circuits, carrier facilities or last-mile paths. “Map TLOCs to genuinely diverse approved transport interfaces and validate policy-based failover” would remedy that alternative situation, but it would not correct the present issue: using only the affected data-plane overlay for operational access can eliminate remote troubleshooting when the fabric fails.

“Validate OMP route advertisements and centralized policy across controllers with intended VPN and TLOC eligibility” is the supported response when data-plane tunnel presence does not guarantee that control-plane route advertisement and segmentation policy deliver needed service prefixes. Here the decisive response is “Provide an appropriately secured independent management path or out-of-band recovery access for critical WAN edges”, so that different intervention does not meet the stated requirement.

Secure SD-WAN fabric admission requires authorized organization identifiers and valid identity trust, not just IP routing. “Design approved CA trust, certificate lifecycle and device authorization procedures for every control node and edge” applies to that other condition. The reported evidence is operations wants to reach branch edges for troubleshooting through an overlay VPN that might be down during a widespread incident; this alternative would address the wrong dependency.

Carrier detection at the local switch does not necessarily detect loss of a remote routed neighbor or intermediate path. “Monitor false BFD flaps and hardware resource limits when tightening liveness timers across many peers” would remedy that alternative situation, but it would not correct the present issue: routing graceful restart requires compatible neighbor capability and safe stale-route lifetimes, not merely redundant uplinks.

“Include root placement and protection checks in switch onboarding templates” is the supported response when without deliberate STP root design, Layer 2 forwarding paths may traverse inappropriate access hardware. Here the decisive response is “Test interactions between graceful restart, BFD and partial data-plane failure before relying on nonstop behavior”, so that different intervention does not meet the stated requirement.

Unprotected edge-port fast transition can introduce topology-change or loop risks if another bridge is attached. “Periodically test edge-port protections and review exceptions for meeting rooms and shared desks” applies to that other condition. The reported evidence is a campus core undergoes control-plane restart and peers immediately purge all routes although forwarding hardware might remain functional during a supported restart interval; this alternative would address the wrong dependency.

That change concerns saas paas iaas service responsibility split, where Cloud service models allocate operational responsibility differently; consuming PaaS normally shifts underlying host management while retaining customer data and access duties. The reported issue instead stems from: gNMI is a model-driven management interface commonly using gRPC streaming and structured path/value messages rather than a generic webpage.

That change concerns telemetry certificate mutual authentication, where TLS mutual authentication depends on valid identity and trust configuration, independent of basic network reachability. In this question the necessary remedy is “Implement a supported gNMI client with secure gRPC connectivity and a valid Subscribe request for modeled paths”, which this alternative does not provide.

That change concerns cloud on ramp sd wan policy, where Traditional centralized route topology can add delay and consume backbone capacity even when local cloud on-ramp options are available. The observed condition is a collector opens an HTTP webpage and expects to receive streaming gNMI telemetry messages as ordinary JSON page content; this mechanism addresses another problem.

A hybrid deployment can transfer sensitive data or metadata across administrative and geographic boundaries even when application compute stays on-premises. “Conduct data-flow mapping and legal residency checks before selecting hybrid SaaS and managed-service integrations” would remedy that alternative situation, but it would not correct the present issue: cloud service models allocate operational responsibility differently; consuming PaaS normally shifts underlying host management while retaining customer data and access duties.

“Validate method, status-code and error-body handling in network API client tests” is the supported response when RESTCONF uses resource-oriented HTTP methods with defined read and write semantics, so GET is not an appropriate configuration write operation. Here the decisive response is “Review shared-responsibility assignments at every workload migration and cloud provider contract change”, so that different intervention does not meet the stated requirement.

Standardized models do not necessarily represent every vendor-specific operational or configuration feature. “Keep proprietary model use isolated and documented so future portability work remains manageable” applies to that other condition. The reported evidence is a development team moves a legacy application to a managed PaaS runtime but budgets for patching its underlying virtual machine host while leaving application access controls unowned; this alternative would address the wrong dependency.

Manual per-prefix policy misses newly onboarded routes when attributes and export rules are not centrally classified. “Govern community naming, collision avoidance and route-leak tests across all border routers” would remedy that alternative situation, but it would not correct the present issue: graceful restart depends on both peers' supported capabilities and bounded stale-route handling, not merely a routing session name.

“Monitor tunnel endpoint resilience and account for encapsulation overhead in path MTU design” is the supported response when an IPv4-only underlay cannot natively carry IPv6 forwarding without an overlay or other transition capability. Here the decisive response is “Test graceful-restart interactions with BFD and forwarding readiness during platform changes”, so that different intervention does not meet the stated requirement.

BGP aggregation can hide component failures and attract traffic for unreachable portions of the summarized prefix. “Audit aggregate announcements and child route health before and after regional outages” applies to that other condition. The reported evidence is a provider BGP edge restarts its control process and a peer immediately removes all routes even though the design expects transient forwarding continuity; this alternative would address the wrong dependency.

A purely hub-and-spoke forwarding policy can add latency and load when the DMVPN design is intended to allow direct spoke shortcuts. “Use a supported DMVPN phase and NHRP routing design that safely establishes eligible spoke-to-spoke tunnels” would remedy that alternative situation, but it would not correct the present issue: GRE provides encapsulation for multiple protocols but does not itself encrypt or authenticate payload confidentiality.

“Align supported NHRP and tunnel registration settings and verify the hub can map the spoke's current public transport address” is the supported response when dynamic spoke resolution needs correct NHRP network ID, authentication, hub mapping and reachable tunnel source rather than only a live Internet connection. Here the decisive response is “Combine supported GRE transport with an appropriate IPsec protection design, or select a secure alternative meeting multicast needs”, so that different intervention does not meet the stated requirement.

Logical dual-circuit contracts may share a physical access path and suffer a common-cause outage. “Choose WAN edge circuits with validated last-mile, provider and facility diversity where the service recovery target requires it” applies to that other condition. The reported evidence is an architect proposes plain GRE between remote branches to carry multicast routing updates and claims GRE alone satisfies corporate confidentiality requirements; this alternative would address the wrong dependency.