Cisco 300-420 Bundle

That change concerns mutual redistribution loop prevention, where Bidirectional multipoint redistribution without route tagging or authoritative direction can reintroduce routes into their source protocol. The reported issue instead stems from: An SVI routed ACL does not necessarily inspect intra-VLAN switched frames that never reach Layer 3 forwarding.

That change concerns vrf-lite campus tenant isolation, where A common routing instance cannot enforce independent overlapping IP destinations and controlled route exposure by itself. In this question the necessary remedy is “Design supported VACL, private VLAN or separate VLAN segmentation according to local traffic patterns and platform capabilities”, which this alternative does not provide.

That change concerns multicampus route summarization boundary, where Missing site-level address summarization increases routing state and exposes the WAN to local campus topology churn. The observed condition is two servers share a VLAN, but security engineers place an ACL only on the routed SVI and assume it filters all direct Layer 2 traffic between them; this mechanism addresses another problem.

Network dual stacking alone does not add AAAA DNS records, IPv6 listening services, security policy or path validation to existing applications. “Plan application-by-application dual-stack readiness including DNS, access controls, routing, management and rollback verification” would remedy that alternative situation, but it would not correct the present issue: IS-IS Level 1 operates within an area while Level 2 provides inter-area connectivity and should bound unwanted topology flooding.

“Use an appropriately generated unique-local IPv6 prefix for suitable internal services alongside routed global addressing where Internet access is needed” is the supported response when provider-dependent global prefixes may require renumbering when upstream connectivity changes and do not replace a stable local-only design. Here the decisive response is “Design appropriate Level 1 and Level 2 adjacency placement with resilient L1/L2 border routers and reachable inter-area summaries”, so that different intervention does not meet the stated requirement.

Typical Ethernet SLAAC uses /64 interface identifiers and ordinary host autoconfiguration expectations are not met by arbitrary longer access prefixes. “Allocate /64 prefixes for SLAAC access segments while using more specialized lengths only in supported and justified designs” applies to that other condition. The reported evidence is an enterprise runs IS-IS across two geographic areas but requires every Level 1 router to store all other areas' detailed link-state information; this alternative would address the wrong dependency.

That change concerns sd access redundant control plane nodes, where A single endpoint map/control-plane service is a common-mode availability risk even with redundant data-plane links. The reported issue instead stems from: Identity group classification requires a trusted policy source and onboarding process rather than arbitrary address-based role guessing.

That change concerns sd access multicast in overlay fabric, where Fabric overlay multicast support and replication design have specific control and data-plane requirements beyond simple underlay multicast reachability. In this question the necessary remedy is “Integrate the fabric with appropriate Cisco ISE identity policy and validated endpoint profiling or authentication flows”, which this alternative does not provide.

That change concerns sd access sgt micro segmentation, where IP-prefix ACLs become brittle when identity and endpoint groups move, while fabric policy can use scalable group-based classification. The observed condition is a design team enables fabric segmentation but never integrates network-access authentication and group assignment, assuming switches infer business roles from host IPs; 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 single physical gateway address makes host access depend on one distribution device even when a second gateway exists.

“Restore approved VLAN trunk reachability and compatible HSRP group and timer settings across both devices” is the supported response when FHRP peers must exchange control messages in a correctly shared VLAN to maintain a single active forwarding role. Here the decisive response is “Design a supported FHRP virtual gateway with aligned priorities, Layer 2 reachability and safe failover between distribution switches”, so that different intervention does not meet the stated requirement.

Gateway role restoration depends on the selected FHRP protocol and its configured preemption settings, not priority numbers alone. “Choose a documented VRRP preemption design with safe delay and reachability tracking that fits service stability goals” applies to that other condition. The reported evidence is a campus user VLAN has two distribution switches, but its hosts use the physical IP of only one switch as the default gateway and lose external connectivity during maintenance; this alternative would address the wrong dependency.

TLS mutual authentication depends on valid identity and trust configuration, independent of basic network reachability. “Deploy approved certificates and trust anchors for the telemetry endpoint and collector, including correct service identity names” would remedy that alternative situation, but it would not correct the present issue: traditional centralized route topology can add delay and consume backbone capacity even when local cloud on-ramp options are available.

“Integrate MPLS L3VPN with approved cloud private routing and select per-tenant VRF and gateway route policies” is the supported response when private transport does not automatically enforce tenant segmentation or prevent unintended route exchange into cloud environments. Here the decisive response is “Design supported cloud on-ramp or cloud gateway integration with controlled routing, identity and service security policy”, so that different intervention does not meet the stated requirement.

GNMI is a model-driven management interface commonly using gRPC streaming and structured path/value messages rather than a generic webpage. “Implement a supported gNMI client with secure gRPC connectivity and a valid Subscribe request for modeled paths” applies to that other condition. The reported evidence is an enterprise uses SD-WAN at branches and wants direct low-latency cloud access, but cloud-hosted routes still hairpin through a remote data center; this alternative would address the wrong dependency.

That change concerns snmpv3 authenticated management design, where Legacy community strings do not provide SNMPv3's user-based authentication and encryption capabilities needed by the policy. The reported issue instead stems from: In-band-only management can share a fault with the network being repaired, eliminating the ability to recover remotely.

That change concerns network management vrf segmentation, where A common routing table broadens the management attack surface and increases risk of route or ACL leakage. In this question the necessary remedy is “Provide secure out-of-band management through independent transport, power and authentication suitable for critical nodes”, which this alternative does not provide.

That change concerns prioritizing network management traffic, where Without proper management traffic classification and minimum bandwidth, congestion can starve necessary operations traffic. The observed condition is a distributed business manages core routers only through their production VPN, and a routing incident removes both business forwarding and remote admin access; this mechanism addresses another problem.

That change concerns cisco sd wan orchestration plane purpose, where The orchestration function helps WAN edges discover and authenticate to the fabric but should not be placed in the regular data forwarding path. The reported issue instead stems from: A hybrid WAN needs explicit route and security decisions because reachability alone does not guarantee sensitive traffic uses approved paths.

That change concerns wan path latency versus bandwidth choice, where Bandwidth alone does not determine application suitability when propagation delay and jitter exceed interactive service limits. In this question the necessary remedy is “Classify traffic by trust and business criticality and apply supported routing or SD-WAN policies for each transport”, which this alternative does not provide.

That change concerns wan failover testing asymmetric return path, where Multihoming and address translation must account for both directions; outbound route changes alone may not preserve return paths. The observed condition is a business retains MPLS for regulated transactional traffic but adds low-cost Internet transport and advertises all private prefixes across both transports without selection policy; this mechanism addresses another problem.

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” 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.

Mixed or unsuitable metric styles can undermine consistent path-cost planning and overflow the intended metric range. “Standardize supported wide-metric design and audit interface cost policies across participating IS-IS devices” 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.

Physical redundancy does not imply control-plane equal-cost path installation or useful flow distribution. “Align appropriate IGP costs and supported equal-cost multipath settings with capacity and symmetric path requirements” would remedy that alternative situation, but it would not correct the present issue: a virtualized or stacked switching design needs supported control, state and multichassis link mechanisms to act as one logical system.

“Design suitable BFD sessions for supported routing peers with conservative scale-aware timer settings” is the supported response when carrier detection at the local switch does not necessarily detect loss of a remote routed neighbor or intermediate path. Here the decisive response is “Select a validated stacking or virtual-switch architecture and plan supervisor, interconnect and software compatibility”, 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 two distribution switches are intended to behave as one logical platform, but engineers assume separate independent control planes deliver the same cross-chassis link semantics; this alternative would address the wrong dependency.

IP reachability does not imply that IKE versions, cryptographic proposals, identities and authentication settings agree across peers. “Plan supported matching IKE/IPsec transforms and identity validation with staged security upgrades on both gateways” would remedy that alternative situation, but it would not correct the present issue: VPN session status can be healthy while mismatched crypto ACLs or traffic selectors omit the application flow.

“Design an approved extranet or shared-services VPN import/export model with explicit prefix filters and security enforcement” is the supported response when tenant route separation blocks cross-VPN reachability until carefully controlled route-target import/export rules make the intended service available. Here the decisive response is “Update both peers' protected prefix definitions and routing design with least-privilege permitted flows”, 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 a site-to-site tunnel negotiates successfully but finance traffic fails because protected subnet traffic selectors exclude one new destination prefix; this alternative would address the wrong dependency.

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.