Cisco 300-420 Bundle

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.

A flat random allocation from the /48 wastes the opportunity for site-level hierarchy and complicates growth and route summarization. “Maintain an IPv6 hierarchy registry and consistently reserve site and functional subnet identifiers before provisioning” 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.

“Include tunnel and encryption overhead in WAN design capacity and test plans” 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 “Record transition architecture decision criteria instead of applying one translation model to every workload”, so that different intervention does not meet the stated requirement.

IPv4-only security rules do not automatically enforce the same trust boundary for IPv6 traffic on a dual-stack path. “Include IPv6 policy and telemetry reviews in every dual-stack readiness audit” 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.

Physical link-up is insufficient to guarantee bidirectional signal integrity, which can affect control-plane protocols and forwarding. “Include unidirectional-link testing in fiber plant acceptance and high-availability reviews” would remedy that alternative situation, but it would not correct the present issue: MST region membership requires consistent region identifier, revision and VLAN mapping rather than matching only some VLAN names.

“Inspect fiber and BPDU loss diagnostics during campus convergence design reviews” is the supported response when a non-designated STP port losing expected control messages can create a loop if it incorrectly assumes the superior path vanished. Here the decisive response is “Version MST configuration centrally and test cross-building changes before enabling additional VLANs”, so that different intervention does not meet the stated requirement.

A per-VLAN spanning-tree model scales protocol state with VLAN count and may become less efficient than suitable aggregated instances. “Include VLAN-count forecasts in campus Layer 2 architecture capacity planning” applies to that other condition. The reported evidence is two campus buildings should share one MST region but have different region names or VLAN-to-instance maps, unexpectedly changing STP behavior at the boundary; this alternative would address the wrong dependency.

Policy percentages alone do not preserve service if critical aggregate traffic exceeds reduced failover link capacity. “Maintain separate primary and failover traffic budgets and test both periodically” would remedy that alternative situation, but it would not correct the present issue: a syntactically installed QoS policy does not establish that actual applications match intended classes or receive required forwarding treatment.

“Measure peak burst distributions and media quality rather than only daily average link utilization” is the supported response when average throughput can hide instantaneous bursts and delay variation that disrupt real-time media even when link utilization seems moderate. Here the decisive response is “Capture before/after QoS telemetry and review counters after software and provider changes”, so that different intervention does not meet the stated requirement.

Traffic classification order and policy constructs can cause broad conditions to overshadow intended more-specific class handling. “Regression-test representative app and protocol matches after editing QoS class definitions” applies to that other condition. The reported evidence is an enterprise labels its QoS design complete because configuration commands were accepted but never checks packet classifications or queue drops; this alternative would address the wrong dependency.

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” would remedy that alternative situation, but it would not correct the present issue: policing enforces a rate by dropping or remarking excess packets, whereas shaping ordinarily smooths outbound bursts using buffers.

“Reserve low-latency priority treatment for justified real-time traffic with controlled bandwidth and balanced class allocations” is the supported response when an oversized or unbounded strict-priority queue can consume interface capacity and deny adequate service to other classes. Here the decisive response is “Use shaping for traffic that can tolerate buffering and selective policing where a hard ingress contract is needed”, so that different intervention does not meet the stated requirement.

Per-flow IntServ state scales differently from aggregated DiffServ classes and can become operationally expensive for large multi-site deployments. “Choose a scalable DiffServ class-based policy where application requirements permit, reserving per-flow mechanisms for justified domains” applies to that other condition. The reported evidence is a design uses aggressive ingress policing for interactive video and expects the policer to buffer all bursts until bandwidth becomes available; this alternative would address the wrong dependency.

An oversized or unbounded strict-priority queue can consume interface capacity and deny adequate service to other classes. “Reserve low-latency priority treatment for justified real-time traffic with controlled bandwidth and balanced class allocations” would remedy that alternative situation, but it would not correct the present issue: a common routing table broadens the management attack surface and increases risk of route or ACL leakage.

“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 “Create a supported management VRF or equivalent separated context and tightly controlled shared services as needed”, so that different intervention does not meet the stated requirement.

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” applies to that other condition. The reported evidence is an enterprise puts SNMP, SSH and backup traffic in the same global routing table as public guest endpoints, complicating access restrictions; this alternative would address the wrong dependency.

Fabric overlay encapsulation adds overhead beyond ordinary IP reachability and depends on a healthy L3 underlay. “Provide resilient IP underlay reachability and adequate end-to-end MTU for supported fabric encapsulation” 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.

“Size border nodes and redundant exits for N-minus-one load, applying failure-domain and traffic-engineering requirements” is the supported response when link redundancy within the fabric does not guarantee sufficient external border forwarding capacity during degraded operation. Here the decisive response is “Design the supported fabric wireless control-plane and data-plane integration with validated WLAN-to-VN mapping”, so that different intervention does not meet the stated requirement.

Physical underlay IP connectivity does not by itself establish appropriate inter-fabric transit, route exchange and segmentation policy. “Design supported fabric-to-fabric transit via qualified borders and consistent virtual-network route and security policy” 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.

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” would remedy that alternative situation, but it would not correct the present issue: RESTCONF uses resource-oriented HTTP methods with defined read and write semantics, so GET is not an appropriate configuration write operation.

“Use platform-supported model-driven telemetry subscriptions for required state paths with sensible reporting intervals and collector capacity” is the supported response when repeated broad request-response polling can impose higher overhead than selective model-driven subscription updates for suitable telemetry. Here the decisive response is “Use supported RESTCONF PATCH, PUT or POST methods at correct YANG resource paths with authorization and content types”, so that different intervention does not meet the stated requirement.

NETCONF and RESTCONF share model-driven concepts but use different protocol transports, operation semantics and session behavior. “Match API protocol to the orchestrator requirements and supported device capabilities, including SSH/XML NETCONF or HTTP/RESTCONF workflows” applies to that other condition. The reported evidence is an automation tool sends a GET request to change a router interface description and assumes any successful HTTP response implies a configuration mutation; this alternative would address the wrong dependency.

Unauthenticated routing adjacencies on a shared segment create topology-manipulation exposure and accidental peer acceptance. “Rotate OSPF peer credentials with planned maintenance and inventory every intended adjacency” would remedy that alternative situation, but it would not correct the present issue: layer 1 carrier state may not reveal a downstream path failure and slow neighbor detection extends blackhole time.

“Include negotiated address-family and next-hop checks in every BGP peer acceptance procedure” is the supported response when a BGP TCP session does not automatically negotiate or advertise every address family without appropriate capabilities and policy. Here the decisive response is “Capacity-plan BFD session counts and monitor instability before enabling aggressive timers across large deployments”, so that different intervention does not meet the stated requirement.

Unrestricted BGP export policy exposes destinations not authorized for upstream announcement and risks routing leaks. “Perform automated prefix allowlist tests and route-leak simulations before modifying BGP transit peers” applies to that other condition. The reported evidence is an OSPF transport remains physically up during a middle-network failure and the route takes too long to reconverge using default Hello and dead timers; this alternative would address the wrong dependency.

That change concerns wake on lan broadcast boundary, where Ordinary directed and local broadcasts do not automatically cross routed boundaries, so an explicit authorized delivery design is required. The reported issue instead stems from: A summary advertised by a border without valid components can attract and blackhole traffic during partial network failures.

That change concerns campus convergence targets and bfd scale, where High session counts and excessively aggressive timers can exhaust control resources and cause false routing flaps. In this question the necessary remedy is “Tie aggregate advertisement to required downstream reachability or redesign summarization and redundancy accordingly”, which this alternative does not provide.

That change concerns asymmetric campus firewall placement, where Stateful inspection needs coherent bidirectional flow visibility, while independent routing cost choices can create asymmetric paths. The observed condition is two redundant campus borders advertise the same summary but only one border has reachability to the specific server block after an internal partition; this mechanism addresses another problem.

A shared provider routing domain cannot preserve independent overlapping tenant address spaces and route targets without isolation. “Select a supported MPLS L3VPN design using separate VPN routing tables and approved route-target import/export policy” would remedy that alternative situation, but it would not correct the present issue: ordinary port-level upgrades may not meet aggregate fiber-capacity and distance requirements when the optical transport must host many independent wavelengths.

“Choose appropriate Metro Ethernet point-to-point or multipoint service topology with explicit VLAN and loop-avoidance design” is the supported response when multipoint Ethernet services and many independent E-Line circuits have different Layer 2 forwarding and spanning-tree implications. Here the decisive response is “Evaluate supported DWDM wavelengths, optics, optical budget, dispersion and protection channels for the transport design”, so that different intervention does not meet the stated requirement.

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” applies to that other condition. The reported evidence is two data centers need many high-throughput channels over existing dark fiber but an architect proposes a single low-rate Ethernet handoff for each future application; this alternative would address the wrong dependency.