Cisco 300-420 Bundle

Overlay headers reduce usable path MTU and blocked ICMPv6 Packet Too Big feedback can prevent Path MTU Discovery. “Budget tunnel overhead in MTU planning, preserve required ICMPv6 control messages and validate endpoints' segment sizes” would remedy that alternative situation, but it would not correct the present issue: BGP additional paths must satisfy supported multipath eligibility rules and configured maximum-path policy to share traffic.

“Choose an aggregate policy with reviewed component-route dependencies, conservative discard behavior and correct reachability design” is the supported response when BGP aggregation can hide component failures and attract traffic for unreachable portions of the summarized prefix. Here the decisive response is “Evaluate path attributes and supported multipath settings, then choose a design that preserves deterministic failover”, so that different intervention does not meet the stated requirement.

An IPv4-only underlay cannot natively carry IPv6 forwarding without an overlay or other transition capability. “Use a supported IPv6-over-IPv4 tunnel with correct endpoint reachability, encapsulation security and effective MTU” applies to that other condition. The reported evidence is an edge device has two BGP paths to the same prefix but operators expect load sharing merely because both routes appear in the neighbor table; this alternative would address the wrong dependency.

Fabric control-plane endpoint-to-location mapping must reflect movement and be consistent with current host registration. “Monitor control-plane registration freshness and duplicate endpoint identities in multibuilding fabrics” would remedy that alternative situation, but it would not correct the present issue: fabric wireless requires supported controller and edge integration and consistent segmentation assignments for mobile clients.

“Check software and platform support for extended-node quantity and uplink design during rollout” is the supported response when extended nodes and ordinary fabric nodes have distinct supported roles and scale limits; uplink connection alone does not confer every fabric service. Here the decisive response is “Test roaming, controller failover and policy consistency before broad fabric wireless expansion”, 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 wireless clients roam between access points attached to a fabric, but engineers have not designed how controllers integrate with fabric edge nodes and virtual networks; this alternative would address the wrong dependency.

That change concerns sd wan application aware routing loss sla, where Static transport preference does not substitute for application-aware path decisions using measured latency, loss and jitter. The reported issue instead stems from: Remote-only controller dependencies and insufficient regional capacity can degrade onboarding, resiliency and convergence at scale.

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. In this question the necessary remedy is “Design supported regional controller and overlay architecture with redundancy, policy consistency and documented capacity limits”, 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 global SD-WAN fabric grows across continents but keeps every edge tied to a distant single control region, causing instability during regional carrier outages; this mechanism addresses another problem.

Bidirectional multipoint redistribution without route tagging or authoritative direction can reintroduce routes into their source protocol. “Apply explicit redistribution filters, tags, metrics and domain ownership at each boundary with deliberate failure fallback” would remedy that alternative situation, but it would not correct the present issue: a conventional port channel cannot span unrelated independent switches without a supported multichassis or stacking mechanism.

“Standardize member configuration and use supported LACP negotiation and consistency checks for the port channel” is the supported response when etherChannel members need compatible Layer 2 settings and negotiated bundling state to represent a correct logical link. Here the decisive response is “Use a validated multichassis EtherChannel, virtual switching, or routed dual-homing design for platform capabilities”, so that different intervention does not meet the stated requirement.

Ordinary directed and local broadcasts do not automatically cross routed boundaries, so an explicit authorized delivery design is required. “Design secure supported WoL relays, proxy agents or local management distribution rather than exposing unrestricted broadcasts” applies to that other condition. The reported evidence is a downstream server is dual-homed to two distribution devices that use an ordinary standalone EtherChannel design unsupported across separate control systems; this alternative would address the wrong dependency.

N-minus-one operation cannot carry combined load if each remaining link lacks spare capacity or business traffic prioritization. “Size redundant WAN capacity for failure-state critical loads or design explicit congestion and traffic-class degradation policy” 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.

“Evaluate supported GET VPN group key distribution and policy design where technology and business requirements fit” is the supported response when traditional point-to-point encryption tunnel meshes may add unnecessary topology and scale complexity for a trusted private routed underlay. 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.

VPN session status can be healthy while mismatched crypto ACLs or traffic selectors omit the application flow. “Update both peers' protected prefix definitions and routing design with least-privilege permitted flows” 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.

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: Logical network separation on one physical direct-connect facility does not eliminate common power, provider or meet-me-room failures.

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. In this question the necessary remedy is “Design redundant cloud interconnects with suitable facility diversity, BGP and controlled Internet or secondary private fallback”, which this alternative does not provide.

That change concerns telemetry certificate mutual authentication, where TLS mutual authentication depends on valid identity and trust configuration, independent of basic network reachability. The observed condition is a business integrates a regional network with public cloud using one dedicated physical circuit and assumes a separate routing VLAN on the same facility provides true disaster tolerance; this mechanism addresses another problem.

Mobile backup is useful only if real coverage, policy, cost and failure independence support required branch services. “Design cellular failover with tested signal strength, provider diversity, data-plan capacity and selective critical traffic routing” would remedy that alternative situation, but it would not correct the present issue: service encapsulation consumes transport overhead and can exceed an underlay MTU that was sized only for native Ethernet payloads.

“Use supported service probing and tracked next-hop or routing convergence to withdraw an unusable primary path” is the supported response when local interface carrier may remain up when upstream service fails, so a static route without health tracking can blackhole traffic. Here the decisive response is “Negotiate and implement supported provider service MTU and customer handoff frame sizes including encapsulation requirements”, so that different intervention does not meet the stated requirement.

Uncontrolled multihoming can select unpredictable exits and cause asymmetry or suboptimal paths under provider changes. “Define local preference, inbound announcement policy and health tracking based on primary and backup business requirements” applies to that other condition. The reported evidence is a provider delivers a Layer 2 VPN between sites with 1500-byte host payloads, but an extra service label and VLAN tag causes dropped frames in one segment; this alternative would address the wrong dependency.

Tenant route separation blocks cross-VPN reachability until carefully controlled route-target import/export rules make the intended service available. “Review route target overlaps and firewall rules together when allowing cross-VPN shared services” 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.

“Include maximum-frame and PMTU tests in every overlay transport acceptance plan” is the supported response when encapsulation and encryption overhead reduce effective path MTU, and missing PMTUD control messages can stall large packets. Here the decisive response is “Reconcile cloud subnet additions with tunnel selectors and routing changes before declaring VPN rollout complete”, so that different intervention does not meet the stated requirement.

IP reachability does not imply that IKE versions, cryptographic proposals, identities and authentication settings agree across peers. “Track cryptographic algorithm and lifetime standards jointly across every VPN peer lifecycle” 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.

That change concerns is-is adjacency authentication design, where An unprotected adjacency trust boundary can admit unauthorized IS-IS control messages into a routing domain. The reported issue instead stems from: Mixed or unsuitable metric styles can undermine consistent path-cost planning and overflow the intended metric range.

That change concerns is-is summary reachable component coverage, where Summary advertisement can attract destinations no longer reachable through the summarizing area, creating a predictable blackhole. In this question the necessary remedy is “Standardize supported wide-metric design and audit interface cost policies across participating IS-IS devices”, which this alternative does not provide.

That change concerns eigrp stub branch query containment, where Unbounded EIGRP query scope and nontransit spokes can prolong active route computation across a large topology. The observed condition is an enterprise upgrades IS-IS for high-capacity links but one region still relies on incompatible metric expectations, producing unintended path preference for long WAN circuits; this mechanism addresses another problem.

Randomly scattered branch subnets prevent region-level summarization and make routing and change control unnecessarily complex. “Use an authoritative IP address management registry with reservation, collision checks and explicit aggregation ownership for new sites” would remedy that alternative situation, but it would not correct the present issue: a flat random allocation from the /48 wastes the opportunity for site-level hierarchy and complicates growth and route summarization.

“Include realistic utilization forecasts and host-capacity arithmetic in IP addressing design signoff rather than relying on prefix labels” is the supported response when an IPv4 /27 ordinarily has only thirty usable host addresses, so it cannot accommodate the stated phones and gateway. Here the decisive response is “Maintain an IPv6 hierarchy registry and consistently reserve site and functional subnet identifiers before provisioning”, so that different intervention does not meet the stated requirement.

A /15 covers two consecutive aligned /16 networks and the selected /15 omits 10.66.0.0/16 while including unintended space. “Require automated prefix containment and component-reachability validation on every proposed aggregate route advertisement” applies to that other condition. The reported evidence is an organization receives an IPv6 /48 and assigns different arbitrary /64s to access LANs without reserving site blocks or a summarization scheme; this alternative would address the wrong dependency.

That change concerns eigrp unequal cost traffic sharing, where EIGRP unequal-cost load sharing is not enabled simply because multiple routes exist and is constrained by feasibility and variance. The reported issue instead stems from: Neighbor authentication parameters and permitted key windows must align or the routing protocol rejects peer messages.

That change concerns eigrp route summarization at hub, where Unnecessary specific-route propagation increases state and change sensitivity without providing required central policy detail. In this question the necessary remedy is “Coordinate supported EIGRP authentication changes and key rollover across both peers with safe cutover”, which this alternative does not provide.

That change concerns eigrp hub topology route leaking, where Uncontrolled bidirectional redistribution can reintroduce routes, create loops and lose source-of-truth route preference. The observed condition is two enterprise EIGRP neighbors cease exchanging routes after only one endpoint changes key identifiers during security hardening; this mechanism addresses another problem.