Cisco 300-420 Bundle

DSCP semantics and provider class-of-service mappings are not necessarily preserved across an independent administrative domain. “Include the provider QoS contract and trust-domain mapping in WAN migration design packages” would remedy that alternative situation, but it would not correct the present issue: priority queuing alone cannot create bandwidth beyond circuit capacity, and too many concurrent sessions can oversubscribe voice allocation.

“Review class allocation totals and projected peak demand as new applications join the WAN” is the supported response when without class-based queue service, different traffic priorities may compete equally under congestion rather than receiving guaranteed minimum allocations. Here the decisive response is “Recalculate concurrent-call capacity whenever codec, provider CIR or secondary WAN path changes”, so that different intervention does not meet the stated requirement.

Random early detection is usually better aligned with responsive TCP queues than with high-priority delay-sensitive voice traffic. “Validate platform queue and drop algorithm selection for each application class” applies to that other condition. The reported evidence is a small branch has a 3 Mbps WAN with no admission control and permits twenty simultaneous high-bitrate voice sessions, causing severe jitter; this alternative would address the wrong dependency.

Priority queuing alone cannot create bandwidth beyond circuit capacity, and too many concurrent sessions can oversubscribe voice allocation. “Design call admission or session limits based on codec overhead and failover bandwidth, with controlled class policies” would remedy that alternative situation, but it would not correct the present issue: DSCP semantics and provider class-of-service mappings are not necessarily preserved across an independent administrative domain.

“Implement appropriate CBWFQ or platform-supported scheduler weights after classifying actual traffic” is the supported response when without class-based queue service, different traffic priorities may compete equally under congestion rather than receiving guaranteed minimum allocations. Here the decisive response is “Negotiate and implement DSCP-to-provider-CoS mapping and verify marking at each trust boundary”, so that different intervention does not meet the stated requirement.

Random early detection is usually better aligned with responsive TCP queues than with high-priority delay-sensitive voice traffic. “Use appropriate congestion avoidance on suitable best-effort TCP classes and protect voice through controlled priority service” applies to that other condition. The reported evidence is a branch marks a critical application with DSCP 46, but the MPLS provider maps it into ordinary treatment because service-class translation was never agreed; this alternative would address the wrong dependency.

A per-VLAN spanning-tree model scales protocol state with VLAN count and may become less efficient than suitable aggregated instances. “Assess MST or Layer 3 access boundaries against actual traffic steering and availability requirements” would remedy that alternative situation, but it would not correct the present issue: superior BPDUs on an untrusted downstream link can alter STP root selection unless the boundary is protected.

“Enable appropriate UDLD modes on supported fiber links and validate shutdown and recovery procedures” is the supported response when physical link-up is insufficient to guarantee bidirectional signal integrity, which can affect control-plane protocols and forwarding. Here the decisive response is “Enable Root Guard on appropriate downstream designated ports and keep intended root roles explicit”, so that different intervention does not meet the stated requirement.

MST region membership requires consistent region identifier, revision and VLAN mapping rather than matching only some VLAN names. “Align approved MST region configuration and verify boundary ports and per-instance root placement” applies to that other condition. The reported evidence is an access switch connected to a third-party tenant device begins sending superior BPDUs and causes the building's STP root to move into the tenant network; this alternative would address the wrong dependency.

That change concerns ntp time quality in network operations, where Uncoordinated system clocks undermine log chronology, audit correlation and incident reconstruction. The reported issue instead stems from: Overly aggressive polling can consume limited control-plane CPU and management bandwidth without improving decision quality.

That change concerns pim sparse mode rendezvous point resilience, where ASM shared-tree setup may depend on reachable RP control functions that need deliberate redundancy. In this question the necessary remedy is “Select telemetry collection intervals and methods proportional to observed change rates and device capacity”, which this alternative does not provide.

That change concerns rpf multicast source route check, where Multicast RPF typically checks the route back toward the source or RP, not merely whether a receiver destination is reachable. The observed condition is a team polls every interface on hundreds of switches every second over the production WAN and then experiences management-plane load spikes; this mechanism addresses another problem.

That change concerns ipsec traffic selector scope, where VPN session status can be healthy while mismatched crypto ACLs or traffic selectors omit the application flow. The reported issue instead stems from: Traditional point-to-point encryption tunnel meshes may add unnecessary topology and scale complexity for a trusted private routed underlay.

That change concerns mpls layer 3 vpn extranet reachability, where Tenant route separation blocks cross-VPN reachability until carefully controlled route-target import/export rules make the intended service available. In this question the necessary remedy is “Evaluate supported GET VPN group key distribution and policy design where technology and business requirements fit”, which this alternative does not provide.

That change concerns ipsec ike proposal compatibility, where IP reachability does not imply that IKE versions, cryptographic proposals, identities and authentication settings agree across peers. The observed condition is a corporate private MPLS WAN needs IP payload confidentiality across many sites without forcing ordinary site-to-site traffic through a tunnel hub; this mechanism addresses another problem.

Fabric wireless requires supported controller and edge integration and consistent segmentation assignments for mobile clients. “Test roaming, controller failover and policy consistency before broad fabric wireless expansion” would remedy that alternative situation, but it would not correct the present issue: extended nodes and ordinary fabric nodes have distinct supported roles and scale limits; uplink connection alone does not confer every fabric service.

“Review transit scalability, border redundancy and trust-boundary translation at every inter-fabric connection” is the supported response when physical underlay IP connectivity does not by itself establish appropriate inter-fabric transit, route exchange and segmentation policy. Here the decisive response is “Check software and platform support for extended-node quantity and uplink design during rollout”, so that different intervention does not meet the stated requirement.

Link redundancy within the fabric does not guarantee sufficient external border forwarding capacity during degraded operation. “Use measured peak traffic and failure-mode utilization when capacity planning SD-Access borders” applies to that other condition. The reported evidence is a campus wants to hang many simple access switches from an SD-Access fabric edge and assumes each automatically has full fabric border and control-plane functionality; this alternative would address the wrong dependency.

That change concerns BGP prefix filter outbound boundary, where Unrestricted BGP export policy exposes destinations not authorized for upstream announcement and risks routing leaks. The reported issue instead stems from: A BGP TCP session does not automatically negotiate or advertise every address family without appropriate capabilities and policy.

That change concerns ospf point-to-point network type, where Default broadcast OSPF network behavior can elect designated routers even when the topology is only a two-router link. In this question the necessary remedy is “Enable intended IPv6 unicast AFI/SAFI activation, reachable next hops and export filtering consistently on peers”, which this alternative does not provide.

That change concerns ospf bfd rapid failure detection, where Layer 1 carrier state may not reveal a downstream path failure and slow neighbor detection extends blackhole time. The observed condition is two enterprise BGP routers establish a TCP session and exchange IPv4 reachability but their IPv6 networks remain absent after enabling the underlying IPv6 interface; this mechanism addresses another problem.

An EIGRP feasible successor must satisfy its feasibility condition relative to the successor's feasible distance to prevent loops. “Review reported and feasible distances and design valid loop-free alternatives rather than forcing an invalid candidate” would remedy that alternative situation, but it would not correct the present issue: uncontrolled bidirectional redistribution can reintroduce routes, create loops and lose source-of-truth route preference.

“Apply well-bounded route summaries at distribution interfaces only after validating component networks and discard consequences” is the supported response when unnecessary specific-route propagation increases state and change sensitivity without providing required central policy detail. Here the decisive response is “Use explicit tag-based redistribution policy, defined metrics and directional filters at well-documented borders”, so that different intervention does not meet the stated requirement.

Neighbor authentication parameters and permitted key windows must align or the routing protocol rejects peer messages. “Coordinate supported EIGRP authentication changes and key rollover across both peers with safe cutover” applies to that other condition. The reported evidence is two autonomous branch EIGRP routing domains redistribute into one core and begin sending learned routes back into the origin domain; this alternative would address the wrong dependency.

ASM initially uses a shared RP tree and may switch to source-specific shortest-path forwarding according to design and platform behavior. “Test multicast forwarding path changes and source-tree utilization for large streaming applications” would remedy that alternative situation, but it would not correct the present issue: a dense many-to-many application can impose excessive source tree state if its delivery model ignores suitable shared bidirectional multicast designs.

“Verify switch snooping and receiver protocol versions before enabling SSM at scale” is the supported response when source-specific multicast applications need supported source-aware receiver membership signaling, commonly IGMPv3 for IPv4. Here the decisive response is “Model source and receiver population, not just one test stream, when selecting multicast mode”, so that different intervention does not meet the stated requirement.

PIM DR election provides a defined designated router role on a multiaccess segment to avoid conflicting join responsibilities. “Record PIM DR priorities and test host join continuity after an access router outage” applies to that other condition. The reported evidence is a collaboration application has many multicast senders in the same group and operators propose building separate source-specific trees for every participant; this alternative would address the wrong dependency.

That change concerns sd wan overlay segmentation with vpn, where An unsegmented overlay routing context can make trust-boundary errors more likely even if some edge access rules exist. The reported issue instead stems from: Static transport preference does not substitute for application-aware path decisions using measured latency, loss and jitter.

That change concerns sd wan local internet breakout security, where Local breakout bypasses central inspection unless equivalent secure edge controls and policy are deliberately placed. In this question the necessary remedy is “Create supported application-aware routing policy with validated SLA class thresholds and fallback behavior”, which this alternative does not provide.

That change concerns sd wan multicast design bandwidth cost, where Naive unicast replication can consume excessive WAN capacity, while multicast support depends on platform and overlay design. The observed condition is a voice collaboration app takes the least-cost broadband transport even when packet loss breaches an SLA because policy only prefers link color and ignores live performance; this mechanism addresses another problem.

That change concerns rapid spanning tree edge port guard, where Unprotected edge-port fast transition can introduce topology-change or loop risks if another bridge is attached. The reported issue instead stems from: Routing graceful restart requires compatible neighbor capability and safe stale-route lifetimes, not merely redundant uplinks.

That change concerns campus stp root placement, where Without deliberate STP root design, Layer 2 forwarding paths may traverse inappropriate access hardware. In this question the necessary remedy is “Use supported graceful restart and nonstop forwarding features only where peer compatibility and forwarding state can be verified”, which this alternative does not provide.

That change concerns campus virtual switching platform abstraction, where A virtualized or stacked switching design needs supported control, state and multichassis link mechanisms to act as one logical system. The observed condition 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 mechanism addresses another problem.