Cisco 300-420 Bundle

Local log storage and rollover cannot substitute for reliable centralized timestamped security event retention. “Design redundant remote syslog collectors with protected transport, appropriate facilities and retention controls” would remedy that alternative situation, but it would not correct the present issue: in-band-only management can share a fault with the network being repaired, eliminating the ability to recover remotely.

“Classify authentic management flows and allocate controlled minimum service within the WAN's QoS policy” is the supported response when without proper management traffic classification and minimum bandwidth, congestion can starve necessary operations traffic. Here the decisive response is “Provide secure out-of-band management through independent transport, power and authentication suitable for critical nodes”, so that different intervention does not meet the stated requirement.

Legacy community strings do not provide SNMPv3's user-based authentication and encryption capabilities needed by the policy. “Design supported SNMPv3 users, auth/privacy mechanisms, least-privilege views and central credential lifecycle” applies to that other condition. The reported evidence 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 alternative would address the wrong dependency.

Encapsulation and encryption overhead reduce effective path MTU, and missing PMTUD control messages can stall large packets. “Include maximum-frame and PMTU tests in every overlay transport acceptance plan” would remedy that alternative situation, but it would not correct the present issue: IP reachability does not imply that IKE versions, cryptographic proposals, identities and authentication settings agree across peers.

“Treat key server redundancy, rekey windows and group membership security as critical design dependencies” 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 “Track cryptographic algorithm and lifetime standards jointly across every VPN peer lifecycle”, so that different intervention does not meet the stated requirement.

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” applies to that other condition. The reported evidence is two enterprise VPN gateways can ping one another but fail to establish a protected site-to-site tunnel after one side moves to a stronger IKE encryption suite; this alternative would address the wrong dependency.

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” would remedy that alternative situation, but it would not correct the present issue: neighbor authentication parameters and permitted key windows must align or the routing protocol rejects peer messages.

“Assess feasible successors and apply an approved variance design with realistic traffic-share expectations” is the supported response when EIGRP unequal-cost load sharing is not enabled simply because multiple routes exist and is constrained by feasibility and variance. Here the decisive response is “Coordinate supported EIGRP authentication changes and key rollover across both peers with safe cutover”, so that different intervention does not meet the stated requirement.

Uncontrolled bidirectional redistribution can reintroduce routes, create loops and lose source-of-truth route preference. “Use explicit tag-based redistribution policy, defined metrics and directional filters at well-documented borders” applies to that other condition. The reported evidence is two enterprise EIGRP neighbors cease exchanging routes after only one endpoint changes key identifiers during security hardening; this alternative would address the wrong dependency.

IP-prefix ACLs become brittle when identity and endpoint groups move, while fabric policy can use scalable group-based classification. “Audit SGT classification and policy matrix changes when onboarding new job roles” would remedy that alternative situation, but it would not correct the present issue: high session counts and excessively aggressive timers can exhaust control resources and cause false routing flaps.

“Include reverse-path verification in campus security zone design and ECMP changes” is the supported response when stateful inspection needs coherent bidirectional flow visibility, while independent routing cost choices can create asymmetric paths. Here the decisive response is “Establish timer and session-count budgets per platform before promising uniform subsecond convergence”, so that different intervention does not meet the stated requirement.

A summary advertised by a border without valid components can attract and blackhole traffic during partial network failures. “Test partial reachability failures, not only complete router outages, when validating multicampus route policy” applies to that other condition. The reported evidence is a design mandates subsecond link failure reaction on hundreds of campus peers and enables aggressive BFD for every adjacency without capacity estimation; this alternative would address the wrong dependency.

NETCONF can expose candidate datastores, locking and commit operations where supported, unlike assuming every management interface has equivalent transactions. “Design a supported NETCONF workflow with lock, edit-config, validate, commit and rollback handling for the device capabilities” would remedy that alternative situation, but it would not correct the present issue: on-change subscriptions report eligible state changes, not necessarily uniformly spaced observations required for some time-series analytics.

“Match API protocol to the orchestrator requirements and supported device capabilities, including SSH/XML NETCONF or HTTP/RESTCONF workflows” is the supported response when NETCONF and RESTCONF share model-driven concepts but use different protocol transports, operation semantics and session behavior. Here the decisive response is “Choose supported periodic or sample telemetry publication with a suitable interval for the planning metric”, so that different intervention does not meet the stated requirement.

Coarse periodic publication can delay visibility of short state transitions and is not equivalent to supported event-driven on-change reporting. “Use supported on-change telemetry for the neighbor state path with safeguards for subscriber load and update volume” applies to that other condition. The reported evidence is a capacity planning service needs a stable one-minute time series but engineers configure only on-change updates and complain that unchanged gauges disappear; this alternative would address the wrong dependency.

Security group policy alone may not replace full virtual-network level route isolation where separate macrosegments are required. “Use virtual-network boundaries for real routing isolation and review any exception-based cross-VN reachability” would remedy that alternative situation, but it would not correct the present issue: unprotected edge-port fast transition can introduce topology-change or loop risks if another bridge is attached.

“Test interactions between graceful restart, BFD and partial data-plane failure before relying on nonstop behavior” 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 “Periodically test edge-port protections and review exceptions for meeting rooms and shared desks”, so that different intervention does not meet the stated requirement.

A virtualized or stacked switching design needs supported control, state and multichassis link mechanisms to act as one logical system. “Evaluate shared-control-plane failure risk and upgrade procedures when choosing platform abstraction over independent switches” applies to that other condition. The reported evidence is a user-facing access port is configured as a fast transition edge port but an employee connects a small switch that starts sending BPDUs; this alternative would address the wrong dependency.

PIM sparse mode forwarding relies on supported multicast routing and receiver membership along the required multicast distribution tree. “Enable appropriate PIM and IGMP behavior on intended routed interfaces and validate RP and RPF reachability” would remedy that alternative situation, but it would not correct the present issue: multicast RPF decisions can be sensitive to unicast path selection, including ECMP and asymmetric routing behavior.

“Assess multicast replication at branching points or other supported content distribution design with receiver policy” is the supported response when naive replicated unicast can consume far more shared-link capacity than a suitable multicast tree for many receivers. Here the decisive response is “Align multicast source reachability and acceptable RPF design with supported ECMP handling and stable upstream selection”, so that different intervention does not meet the stated requirement.

RP location affects shared-tree path efficiency and control resilience for ASM groups and can create a remote common-mode dependency. “Choose strategically located and redundant RPs considering source and receiver topology, routing cost and failover” applies to that other condition. The reported evidence is an enterprise adds an equal-cost WAN path and multicast traffic begins failing because the selected upstream RPF path differs from the ingress interface chosen by a source; this alternative would address the wrong dependency.

A virtualized or stacked switching design needs supported control, state and multichassis link mechanisms to act as one logical system. “Select a validated stacking or virtual-switch architecture and plan supervisor, interconnect and software compatibility” 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.

“Apply supported PortFast or edge behavior with BPDU Guard and an approved exception procedure for genuine uplinks” is the supported response when unprotected edge-port fast transition can introduce topology-change or loop risks if another bridge is attached. Here the decisive response is “Use supported graceful restart and nonstop forwarding features only where peer compatibility and forwarding state can be verified”, so that different intervention does not meet the stated requirement.

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” 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.

Protocol adjacency and IPv4 routes do not alone establish correct IPv6 reachability, interface addressing or address-family support. “Test IPv4 and IPv6 reachability separately when extending a stable routing protocol deployment” would remedy that alternative situation, but it would not correct the present issue: an IPv4 /27 ordinarily has only thirty usable host addresses, so it cannot accommodate the stated phones and gateway.

“Use an authoritative IP address management registry with reservation, collision checks and explicit aggregation ownership for new sites” is the supported response when randomly scattered branch subnets prevent region-level summarization and make routing and change control unnecessarily complex. Here the decisive response is “Include realistic utilization forecasts and host-capacity arithmetic in IP addressing design signoff rather than relying on prefix labels”, 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 a campus plans an ordinary IPv4 /27 for a voice VLAN with seventy active phones and expects enough usable addresses after adding a default gateway; this alternative would address the wrong dependency.

A normal area floods external routing information that stub-capable branches may not need when a default route is sufficient. “Choose a supported stub-area design consistently across the area and ensure the ABR provides an appropriate default route” would remedy that alternative situation, but it would not correct the present issue: translation adds stateful dependencies and application edge cases that may be unnecessary when a controlled native dual-stack phase is viable.

“Budget tunnel overhead in MTU planning, preserve required ICMPv6 control messages and validate endpoints' segment sizes” is the supported response when overlay headers reduce usable path MTU and blocked ICMPv6 Packet Too Big feedback can prevent Path MTU Discovery. Here the decisive response is “Select native dual stack for capable segments and reserve translation for real IPv4-only boundaries with documented requirements”, so that different intervention does not meet the stated requirement.

IPv6-only clients cannot communicate with IPv4-only services without supported translation and suitable destination synthesis. “Design appropriate NAT64 plus DNS64 service boundaries, DNS behavior and application compatibility exceptions” applies to that other condition. The reported evidence is a migration team proposes full NAT64 for an entire enterprise even though most applications and WAN devices already support IPv6 and IPv4 simultaneously; this alternative would address the wrong dependency.

That change concerns cisco sd wan management plane resilience, where Management availability and existing data-plane forwarding have different dependencies, while loss of manageability remains an operational risk. The reported issue instead stems from: Data-plane tunnel presence does not guarantee that control-plane route advertisement and segmentation policy deliver needed service prefixes.

That change concerns cisco sd wan transport tloc diversity, where Logical transport labels or TLOCs do not inherently represent independent circuits, carrier facilities or last-mile paths. In this question the necessary remedy is “Validate OMP route advertisements and centralized policy across controllers with intended VPN and TLOC eligibility”, which this alternative does not provide.

That change concerns cisco sd wan controller certificate trust, where Secure SD-WAN fabric admission requires authorized organization identifiers and valid identity trust, not just IP routing. The observed condition is a new branch has functioning encrypted transport tunnels but receives no remote service routes because centralized SD-WAN control policies omit the site; this mechanism addresses another problem.