Cisco 300-420 Bundle

FHRP peers must exchange control messages in a correctly shared VLAN to maintain a single active forwarding role. “Audit VLAN membership and FHRP peer reachability before modifying router priority values” would remedy that alternative situation, but it would not correct the present issue: gateway role restoration depends on the selected FHRP protocol and its configured preemption settings, not priority numbers alone.

“Compare first-hop load sharing and operational complexity before selecting a protocol solely for redundancy” is the supported response when traditional active-standby first-hop redundancy does not by itself provide the desired per-client gateway load distribution. Here the decisive response is “Document whether automatic takeover or stability-first non-preemption is intended for each critical VLAN”, so that different intervention does not meet the stated requirement.

FHRP presence alone may not account for upstream path viability without appropriate object or interface tracking. “Validate gateway priority changes against real upstream failures rather than only powering off the active switch” applies to that other condition. The reported evidence is after a higher-priority distribution router returns from maintenance, operations expects it to become master automatically but the chosen VRRP preemption behavior was disabled; 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. “Document datastore capabilities and session failure recovery before using transactional network automation” would remedy that alternative situation, but it would not correct the present issue: machine-readable data model revisions and capabilities can differ across platform versions even if management connectivity remains healthy.

“Test cross-vendor schema availability before promising identical API behavior for every device” is the supported response when vendor-native data models may expose platform-specific schema that cannot be queried identically across different vendors. Here the decisive response is “Include API schema contract tests and rollback in every network software upgrade program”, so that different intervention does not meet the stated requirement.

Standardized models do not necessarily represent every vendor-specific operational or configuration feature. “Keep proprietary model use isolated and documented so future portability work remains manageable” applies to that other condition. The reported evidence is a network automation release breaks when some routers are upgraded to a newer software image that exposes changed model revisions and namespaces; this alternative would address the wrong dependency.

Multicast RPF typically checks the route back toward the source or RP, not merely whether a receiver destination is reachable. “Verify RPF interfaces after changing unicast costs or adding asymmetric WAN paths” would remedy that alternative situation, but it would not correct the present issue: uncoordinated system clocks undermine log chronology, audit correlation and incident reconstruction.

“Capacity-test telemetry subscription counts and sampling periods before expanding monitoring fleets” is the supported response when overly aggressive polling can consume limited control-plane CPU and management bandwidth without improving decision quality. Here the decisive response is “Monitor clock drift and NTP source reachability after management VRF and firewall changes”, so that different intervention does not meet the stated requirement.

ASM shared-tree setup may depend on reachable RP control functions that need deliberate redundancy. “Include RP election, anycast or redundancy testing during multicast design acceptance” applies to that other condition. The reported evidence is two distribution devices report the same routing flap five minutes apart because one device uses an unsynchronized clock; this alternative would address the wrong dependency.

That change concerns multicast boundary group filtering, where Without explicit multicast boundary control, group advertisements or forwarding may extend beyond authorized trust domains. The reported issue instead stems from: Legacy community strings do not provide SNMPv3's user-based authentication and encryption capabilities needed by the policy.

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 “Design supported SNMPv3 users, auth/privacy mechanisms, least-privilege views and central credential lifecycle”, 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 large enterprise collects SNMP interface counters using a shared SNMPv2 community across all regions and must meet per-user authentication and privacy controls; this mechanism addresses another problem.

Logical network separation on one physical direct-connect facility does not eliminate common power, provider or meet-me-room failures. “Design redundant cloud interconnects with suitable facility diversity, BGP and controlled Internet or secondary private fallback” would remedy that alternative situation, but it would not correct the present issue: TLS mutual authentication depends on valid identity and trust configuration, independent of basic network reachability.

“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 “Deploy approved certificates and trust anchors for the telemetry endpoint and collector, including correct service identity names”, so that different intervention does not meet the stated requirement.

Traditional centralized route topology can add delay and consume backbone capacity even when local cloud on-ramp options are available. “Design supported cloud on-ramp or cloud gateway integration with controlled routing, identity and service security policy” applies to that other condition. The reported evidence is a new telemetry collector can reach router TCP ports but the router refuses the gRPC session because the client and server certificate trust chains are not configured; this alternative would address the wrong dependency.

That change concerns ospf area 0 resilient backbone, where OSPF hierarchical inter-area connectivity depends on a stable backbone design and resilient area border connectivity. The reported issue instead stems from: A fragmented area-address plan and missing ABR inter-area summarization cause avoidable detailed LSAs to propagate.

That change concerns ospf stub area external lsa control, where A normal area floods external routing information that stub-capable branches may not need when a default route is sufficient. In this question the necessary remedy is “Allocate summarizable ranges and apply appropriate ABR area range configuration with complete component-route validation”, which this alternative does not provide.

That change concerns ospf nssa external redistribution, where A totally stubby or regular stub area cannot originate external LSAs through an internal ASBR in the required manner. The observed condition is dozens of contiguous branch prefixes are flooded individually into the OSPF backbone after a regional restructuring, increasing LSDB churn; this mechanism addresses another problem.

Legacy community strings do not provide SNMPv3's user-based authentication and encryption capabilities needed by the policy. “Rotate SNMPv3 credentials and test monitoring continuity across device replacements” would remedy that alternative situation, but it would not correct the present issue: without proper management traffic classification and minimum bandwidth, congestion can starve necessary operations traffic.

“Test the independent OOB path and break-glass credentials during scheduled resilience drills” is the supported response when in-band-only management can share a fault with the network being repaired, eliminating the ability to recover remotely. Here the decisive response is “Keep management class membership restricted to approved control services and monitor for abuse”, so that different intervention does not meet the stated requirement.

Local log storage and rollover cannot substitute for reliable centralized timestamped security event retention. “Review logging health and retention policy across all management routing contexts” applies to that other condition. The reported evidence is a WAN runs at capacity during remote backup jobs and incident responders lose SSH and telemetry access precisely when troubleshooting is needed; this alternative would address the wrong dependency.

That change concerns cloud direct connect redundant circuits, where Logical network separation on one physical direct-connect facility does not eliminate common power, provider or meet-me-room failures. The reported issue instead stems from: Private transport does not automatically enforce tenant segmentation or prevent unintended route exchange into cloud environments.

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 “Integrate MPLS L3VPN with approved cloud private routing and select per-tenant VRF and gateway route policies”, which this alternative does not provide.

That change concerns gnmi subscribe and grpc transport, where gNMI is a model-driven management interface commonly using gRPC streaming and structured path/value messages rather than a generic webpage. The observed condition is a financial institution wants dedicated provider L3VPN connectivity to cloud private resources and proposes exporting every enterprise VRF into one common cloud virtual network; this mechanism addresses another problem.

Input classification and policing operate on traffic entering an interface, while output scheduling applies to egress congestion. “Require interface-direction diagrams when reviewing QoS policies” would remedy that alternative situation, but it would not correct the present issue: traffic classification order and policy constructs can cause broad conditions to overshadow intended more-specific class handling.

“Maintain separate primary and failover traffic budgets and test both periodically” is the supported response when policy percentages alone do not preserve service if critical aggregate traffic exceeds reduced failover link capacity. Here the decisive response is “Regression-test representative app and protocol matches after editing QoS class definitions”, so that different intervention does not meet the stated requirement.

A syntactically installed QoS policy does not establish that actual applications match intended classes or receive required forwarding treatment. “Capture before/after QoS telemetry and review counters after software and provider changes” applies to that other condition. The reported evidence is a provider WAN policy places a broad match-any business group before a specific real-time collaboration class, so important voice traffic gets generic treatment; this alternative would address the wrong dependency.

Naive replicated unicast can consume far more shared-link capacity than a suitable multicast tree for many receivers. “Benchmark group sizes and failure behavior before replacing unicast with multicast distribution” would remedy that alternative situation, but it would not correct the present issue: PIM sparse mode forwarding relies on supported multicast routing and receiver membership along the required multicast distribution tree.

“Verify source-tree RPF after routing metric changes rather than only testing unicast ping” is the supported response when multicast RPF decisions can be sensitive to unicast path selection, including ECMP and asymmetric routing behavior. Here the decisive response is “Include receiver-driven join tests and group-state verification on every routed multicast hop”, so that different intervention does not meet the stated requirement.

Without explicit multicast boundary control, group advertisements or forwarding may extend beyond authorized trust domains. “Audit group range ownership and multicast boundary filters whenever a new partner network connects” applies to that other condition. The reported evidence is a multicast stream is sourced at headquarters but branch routers never send joins for newly subscribed remote receivers, despite working unicast tunnels; this alternative would address the wrong dependency.

A single physical gateway address makes host access depend on one distribution device even when a second gateway exists. “Design a supported FHRP virtual gateway with aligned priorities, Layer 2 reachability and safe failover between distribution switches” would remedy that alternative situation, but it would not correct the present issue: FHRP peers must exchange control messages in a correctly shared VLAN to maintain a single active forwarding role.

“Choose a documented VRRP preemption design with safe delay and reachability tracking that fits service stability goals” is the supported response when gateway role restoration depends on the selected FHRP protocol and its configured preemption settings, not priority numbers alone. Here the decisive response is “Restore approved VLAN trunk reachability and compatible HSRP group and timer settings across both devices”, so that different intervention does not meet the stated requirement.

FHRP presence alone may not account for upstream path viability without appropriate object or interface tracking. “Track the required upstream path and decrement priority enough for a healthy standby gateway to assume forwarding” applies to that other condition. The reported evidence is two redundant distribution switches both believe they are HSRP active after a VLAN trunk blocks hello messages, causing inconsistent gateway ARP responses; this alternative would address the wrong dependency.