Cisco 300-420 Bundle

Security group policy alone may not replace full virtual-network level route isolation where separate macrosegments are required. “Design distinct fabric virtual networks with appropriate external borders and tightly defined shared services” would remedy that alternative situation, but it would not correct the present issue: a fabric control plane supplies locator information, while the data plane uses supported VXLAN encapsulation to carry endpoint traffic.

“Use supported redundant LISP control-plane nodes and verify endpoint registration and mapping refresh behavior” is the supported response when fabric control-plane endpoint-to-location mapping must reflect movement and be consistent with current host registration. Here the decisive response is “Design overlay forwarding paths with validated VXLAN reachability, fabric edge encapsulation and proper transport MTU”, so that different intervention does not meet the stated requirement.

Ordinary underlay reachability does not assign endpoint onboarding and VXLAN edge functions to a nonfabric access device. “Provision eligible access devices as supported fabric edge nodes and verify host onboarding and virtual network assignments” applies to that other condition. The reported evidence is a campus engineer describes LISP mapping updates as the mechanism transporting user data between fabric edges and neglects overlay tunnel reachability; this alternative would address the wrong dependency.

That change concerns qos oversubscription during backup, where Policy percentages alone do not preserve service if critical aggregate traffic exceeds reduced failover link capacity. The reported issue instead stems from: Input classification and policing operate on traffic entering an interface, while output scheduling applies to egress congestion.

That change concerns qos validation with actual queue counters, where A syntactically installed QoS policy does not establish that actual applications match intended classes or receive required forwarding treatment. In this question the necessary remedy is “Place supported ingress policing and remarking at appropriate boundaries and egress queuing at the actual bottleneck”, which this alternative does not provide.

That change concerns video traffic burst and jitter buffer design, where Average throughput can hide instantaneous bursts and delay variation that disrupt real-time media even when link utilization seems moderate. The observed condition is a campus operator attaches an output queue policy to a branch WAN interface but expects it to police inbound untrusted DSCP markings from the carrier; this mechanism addresses another problem.

Unprotected edge-port fast transition can introduce topology-change or loop risks if another bridge is attached. “Apply supported PortFast or edge behavior with BPDU Guard and an approved exception procedure for genuine uplinks” would remedy that alternative situation, but it would not correct the present issue: fabric overlay multicast support and replication design have specific control and data-plane requirements beyond simple underlay multicast reachability.

“Design distinct fabric virtual networks with appropriate external borders and tightly defined shared services” is the supported response when security group policy alone may not replace full virtual-network level route isolation where separate macrosegments are required. Here the decisive response is “Select a supported SD-Access multicast forwarding model and test receivers across fabric edges and virtual networks”, so that different intervention does not meet the stated requirement.

A single endpoint map/control-plane service is a common-mode availability risk even with redundant data-plane links. “Design supported control-plane node redundancy and test endpoint registration continuity during node loss” applies to that other condition. The reported evidence is an enterprise uses multicast video across a campus fabric but assumes ordinary underlay PIM subscriptions automatically deliver overlay multicast groups end to end; this alternative would address the wrong dependency.

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” would remedy that alternative situation, but it would not correct the present issue: an EIGRP feasible successor must satisfy its feasibility condition relative to the successor's feasible distance to prevent loops.

“Use explicit tag-based redistribution policy, defined metrics and directional filters at well-documented borders” is the supported response when uncontrolled bidirectional redistribution can reintroduce routes, create loops and lose source-of-truth route preference. Here the decisive response is “Review reported and feasible distances and design valid loop-free alternatives rather than forcing an invalid candidate”, so that different intervention does not meet the stated requirement.

Unnecessary specific-route propagation increases state and change sensitivity without providing required central policy detail. “Apply well-bounded route summaries at distribution interfaces only after validating component networks and discard consequences” applies to that other condition. The reported evidence is an enterprise asks EIGRP to install an alternate path solely because the alternate advertised distance is low, without checking the feasibility condition; this alternative would address the wrong dependency.

Conventional iBGP full mesh grows quadratically and becomes costly to configure, observe and recover. “Introduce redundant route reflectors with appropriate client hierarchy and loop-prevention identifiers” would remedy that alternative situation, but it would not correct the present issue: unbounded EIGRP query scope and nontransit spokes can prolong active route computation across a large topology.

“Advertise summaries only with valid downstream coverage or an explicitly documented safe discard and failover behavior” is the supported response when summary advertisement can attract destinations no longer reachable through the summarizing area, creating a predictable blackhole. Here the decisive response is “Declare eligible nontransit branches as EIGRP stubs and summarize at appropriate aggregation points with verified alternate paths”, so that different intervention does not meet the stated requirement.

Protocol adjacency and IPv4 routes do not alone establish correct IPv6 reachability, interface addressing or address-family support. “Implement supported IS-IS IPv6 reachability with interface family configuration and consistent topology preferences” applies to that other condition. The reported evidence is a large hub-and-spoke EIGRP deployment sends queries into hundreds of branch routers during a core route failure, increasing convergence delay; this alternative would address the wrong dependency.

Without deliberate STP root design, Layer 2 forwarding paths may traverse inappropriate access hardware. “Set primary and backup STP roots on appropriate distribution devices and validate bridge priority and path costs” would remedy that alternative situation, but it would not correct the present issue: carrier detection at the local switch does not necessarily detect loss of a remote routed neighbor or intermediate path.

“Select a validated stacking or virtual-switch architecture and plan supervisor, interconnect and software compatibility” is the supported response when a virtualized or stacked switching design needs supported control, state and multichassis link mechanisms to act as one logical system. Here the decisive response is “Design suitable BFD sessions for supported routing peers with conservative scale-aware timer settings”, so that different intervention does not meet the stated requirement.

Routing graceful restart requires compatible neighbor capability and safe stale-route lifetimes, not merely redundant uplinks. “Use supported graceful restart and nonstop forwarding features only where peer compatibility and forwarding state can be verified” applies to that other condition. The reported evidence is a distribution-to-core Ethernet link stays administratively up while a transport device in the middle fails, and routing reconverges only after slow protocol timeouts; this alternative would address the wrong dependency.

That change concerns qos policing versus buffering behavior, where Policing enforces a rate by dropping or remarking excess packets, whereas shaping ordinarily smooths outbound bursts using buffers. The reported issue instead stems from: An oversized or unbounded strict-priority queue can consume interface capacity and deny adequate service to other classes.

That change concerns qos shaping on provider lower rate link, where A high-speed physical port does not imply equal committed service rate, so uncontrolled bursts can be discarded in the provider network. In this question the necessary remedy is “Reserve low-latency priority treatment for justified real-time traffic with controlled bandwidth and balanced class allocations”, which this alternative does not provide.

That change concerns diffserv versus intserv service model, where Per-flow IntServ state scales differently from aggregated DiffServ classes and can become operationally expensive for large multi-site deployments. The observed condition is an enterprise places voice, video, backups and database replication in one strict-priority class, and ordinary business applications starve during a site backup; this mechanism addresses another problem.

Traditional active-standby first-hop redundancy does not by itself provide the desired per-client gateway load distribution. “Consider GLBP where supported or a different routed access and anycast design, based on platform capability and operational needs” would remedy that alternative situation, but it would not correct the present issue: a per-VLAN spanning-tree model scales protocol state with VLAN count and may become less efficient than suitable aggregated instances.

“Align approved MST region configuration and verify boundary ports and per-instance root placement” is the supported response when MST region membership requires consistent region identifier, revision and VLAN mapping rather than matching only some VLAN names. Here the decisive response is “Assess MST or Layer 3 access boundaries against actual traffic steering and availability requirements”, so that different intervention does not meet the stated requirement.

Superior BPDUs on an untrusted downstream link can alter STP root selection unless the boundary is protected. “Enable Root Guard on appropriate downstream designated ports and keep intended root roles explicit” applies to that other condition. The reported evidence is a campus uses hundreds of VLANs with distinct rapid spanning-tree instances and experiences growing CPU and change-control complexity; this alternative would address the wrong dependency.

RESTCONF uses resource-oriented HTTP methods with defined read and write semantics, so GET is not an appropriate configuration write operation. “Use supported RESTCONF PATCH, PUT or POST methods at correct YANG resource paths with authorization and content types” would remedy that alternative situation, but it would not correct the present issue: NETCONF and RESTCONF share model-driven concepts but use different protocol transports, operation semantics and session behavior.

“Use supported on-change telemetry for the neighbor state path with safeguards for subscriber load and update volume” is the supported response when coarse periodic publication can delay visibility of short state transitions and is not equivalent to supported event-driven on-change reporting. Here the decisive response is “Match API protocol to the orchestrator requirements and supported device capabilities, including SSH/XML NETCONF or HTTP/RESTCONF workflows”, so that different intervention does not meet the stated requirement.

On-change subscriptions report eligible state changes, not necessarily uniformly spaced observations required for some time-series analytics. “Choose supported periodic or sample telemetry publication with a suitable interval for the planning metric” applies to that other condition. The reported evidence is a controller team chooses NETCONF for an HTTP-native integration solely because both interfaces use YANG models and assumes their framing and transports are interchangeable; 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. “Design suitable BFD sessions for supported routing peers with conservative scale-aware timer settings” would remedy that alternative situation, but it would not correct the present issue: without deliberate STP root design, Layer 2 forwarding paths may traverse inappropriate access hardware.

“Use supported graceful restart and nonstop forwarding features only where peer compatibility and forwarding state can be verified” is the supported response when routing graceful restart requires compatible neighbor capability and safe stale-route lifetimes, not merely redundant uplinks. Here the decisive response is “Set primary and backup STP roots on appropriate distribution devices and validate bridge priority and path costs”, 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. “Apply supported PortFast or edge behavior with BPDU Guard and an approved exception procedure for genuine uplinks” applies to that other condition. The reported evidence is a campus has redundant access trunks but an unmanaged access switch wins spanning-tree root after it comes online with an unexpectedly favorable bridge priority; this alternative would address the wrong dependency.

Encapsulation and encryption overhead reduce effective path MTU, and missing PMTUD control messages can stall large packets. “Budget tunnel overhead, validate tunnel MTU/MSS adjustment and preserve necessary ICMP feedback” would remedy that alternative situation, but it would not correct the present issue: tenant route separation blocks cross-VPN reachability until carefully controlled route-target import/export rules make the intended service available.

“Plan supported matching IKE/IPsec transforms and identity validation with staged security upgrades on both gateways” is the supported response when IP reachability does not imply that IKE versions, cryptographic proposals, identities and authentication settings agree across peers. Here the decisive response is “Design an approved extranet or shared-services VPN import/export model with explicit prefix filters and security enforcement”, so that different intervention does not meet the stated requirement.

Traditional point-to-point encryption tunnel meshes may add unnecessary topology and scale complexity for a trusted private routed underlay. “Evaluate supported GET VPN group key distribution and policy design where technology and business requirements fit” applies to that other condition. The reported evidence is two enterprise departments use separate MPLS VPNs but need access to one shared CRM subnet without importing all routes from one another; this alternative would address the wrong dependency.