Cisco 300-420 Bundle

Naive unicast replication can consume excessive WAN capacity, while multicast support depends on platform and overlay design. “Choose a supported multicast distribution and replication approach with measured receiver count and transport constraints” would remedy that alternative situation, but it would not correct the present issue: local breakout bypasses central inspection unless equivalent secure edge controls and policy are deliberately placed.

“Design supported regional controller and overlay architecture with redundancy, policy consistency and documented capacity limits” is the supported response when remote-only controller dependencies and insufficient regional capacity can degrade onboarding, resiliency and convergence at scale. Here the decisive response is “Design approved branch egress security with local firewall, cloud security service or appropriate service chaining”, so that different intervention does not meet the stated requirement.

Static transport preference does not substitute for application-aware path decisions using measured latency, loss and jitter. “Create supported application-aware routing policy with validated SLA class thresholds and fallback behavior” applies to that other condition. The reported evidence is a branch enables direct SaaS Internet breakout to improve performance but the original design assumes all egress is filtered by the data center firewall; this alternative would address the wrong dependency.

Traditional centralized route topology can add delay and consume backbone capacity even when local cloud on-ramp options are available. “Validate cloud route advertisement, return path and security controls before enabling distributed cloud breakout” would remedy that alternative situation, but it would not correct the present issue: logical network separation on one physical direct-connect facility does not eliminate common power, provider or meet-me-room failures.

“Monitor certificate expiration and automate approved renewal across telemetry collectors and devices” is the supported response when TLS mutual authentication depends on valid identity and trust configuration, independent of basic network reachability. Here the decisive response is “Review provider location and device diversity rather than treating two logical virtual interfaces as two physical links”, so that different intervention does not meet the stated requirement.

Private transport does not automatically enforce tenant segmentation or prevent unintended route exchange into cloud environments. “Audit cloud gateway, route-target and BGP export policy at each new private cloud interconnect” applies to that other condition. The reported evidence 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 alternative would address the wrong dependency.

That change concerns get vpn any to any encryption, where Traditional point-to-point encryption tunnel meshes may add unnecessary topology and scale complexity for a trusted private routed underlay. The reported issue instead stems from: Encapsulation and encryption overhead reduce effective path MTU, and missing PMTUD control messages can stall large packets.

That change concerns mpls layer 3 vpn extranet reachability, where Tenant route separation blocks cross-VPN reachability until carefully controlled route-target import/export rules make the intended service available. In this question the necessary remedy is “Budget tunnel overhead, validate tunnel MTU/MSS adjustment and preserve necessary ICMP feedback”, which this alternative does not provide.

That change concerns ipsec traffic selector scope, where VPN session status can be healthy while mismatched crypto ACLs or traffic selectors omit the application flow. The observed condition is a branch adds GRE over IPsec and experiences intermittent large-file transfer failures even though small test pings work; this mechanism addresses another problem.

Stateful inspection needs coherent bidirectional flow visibility, while independent routing cost choices can create asymmetric paths. “Select a topology and route policy that maintain suitable symmetric inspected paths or supported state sharing” would remedy that alternative situation, but it would not correct the present issue: a summary advertised by a border without valid components can attract and blackhole traffic during partial network failures.

“Model required convergence classes and scale BFD deployment selectively on critical routed interfaces” is the supported response when high session counts and excessively aggressive timers can exhaust control resources and cause false routing flaps. Here the decisive response is “Tie aggregate advertisement to required downstream reachability or redesign summarization and redundancy accordingly”, so that different intervention does not meet the stated requirement.

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” applies to that other condition. The reported evidence 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 alternative would address the wrong dependency.

Logical transport labels or TLOCs do not inherently represent independent circuits, carrier facilities or last-mile paths. “Map TLOCs to genuinely diverse approved transport interfaces and validate policy-based failover” would remedy that alternative situation, but it would not correct the present issue: secure SD-WAN fabric admission requires authorized organization identifiers and valid identity trust, not just IP routing.

“Design redundant supported SD-WAN Managers with backup, RBAC and regional management reachability as appropriate” is the supported response when management availability and existing data-plane forwarding have different dependencies, while loss of manageability remains an operational risk. Here the decisive response is “Design approved CA trust, certificate lifecycle and device authorization procedures for every control node and edge”, so that different intervention does not meet the stated requirement.

Data-plane tunnel presence does not guarantee that control-plane route advertisement and segmentation policy deliver needed service prefixes. “Validate OMP route advertisements and centralized policy across controllers with intended VPN and TLOC eligibility” applies to that other condition. The reported evidence is a new SD-WAN edge has Internet reachability but cannot join the fabric because controller identity and certificate chain checks are not satisfied; this alternative would address the wrong dependency.

Link redundancy within the fabric does not guarantee sufficient external border forwarding capacity during degraded operation. “Size border nodes and redundant exits for N-minus-one load, applying failure-domain and traffic-engineering requirements” would remedy that alternative situation, but it would not correct the present issue: physical underlay IP connectivity does not by itself establish appropriate inter-fabric transit, route exchange and segmentation policy.

“Design the supported fabric wireless control-plane and data-plane integration with validated WLAN-to-VN mapping” is the supported response when fabric wireless requires supported controller and edge integration and consistent segmentation assignments for mobile clients. Here the decisive response is “Design supported fabric-to-fabric transit via qualified borders and consistent virtual-network route and security policy”, so that different intervention does not meet the stated requirement.

Extended nodes and ordinary fabric nodes have distinct supported roles and scale limits; uplink connection alone does not confer every fabric service. “Use supported extended-node topology with appropriate fabric-edge parent capacity and port-assignment design” applies to that other condition. The reported evidence is two independent SD-Access fabrics need policy-governed intersite reachability, but engineers connect only their individual IP underlays and expect overlay virtual networks to merge; this alternative would address the wrong dependency.

Average throughput can hide instantaneous bursts and delay variation that disrupt real-time media even when link utilization seems moderate. “Reserve suitable queue and burst tolerance based on codec behavior, media priority and empirically observed peak load” would remedy that alternative situation, but it would not correct the present issue: policy percentages alone do not preserve service if critical aggregate traffic exceeds reduced failover link capacity.

“Refine class-map criteria and supported policy evaluation to classify the real-time flows before generic groups” is the supported response when traffic classification order and policy constructs can cause broad conditions to overshadow intended more-specific class handling. Here the decisive response is “Create degraded-mode QoS and application admission policy based on backup capacity and essential services”, so that different intervention does not meet the stated requirement.

Input classification and policing operate on traffic entering an interface, while output scheduling applies to egress congestion. “Place supported ingress policing and remarking at appropriate boundaries and egress queuing at the actual bottleneck” applies to that other condition. The reported evidence is a branch's primary WAN has 100 Mbps and backup cellular has 15 Mbps, but both use the same traffic allocation values with no degraded-mode plan; this alternative would address the wrong dependency.

That change concerns pim sparse mode receiver path joins, where PIM sparse mode forwarding relies on supported multicast routing and receiver membership along the required multicast distribution tree. The reported issue instead stems from: RP location affects shared-tree path efficiency and control resilience for ASM groups and can create a remote common-mode dependency.

That change concerns multicast source rpf under ecmp, where Multicast RPF decisions can be sensitive to unicast path selection, including ECMP and asymmetric routing behavior. In this question the necessary remedy is “Choose strategically located and redundant RPs considering source and receiver topology, routing cost and failover”, which this alternative does not provide.

That change concerns multicast scaling versus replicated unicast, where Naive replicated unicast can consume far more shared-link capacity than a suitable multicast tree for many receivers. The observed condition is an enterprise places its single PIM rendezvous point at a remote edge site with unstable connectivity and sees long join delays for the entire multicast domain; this mechanism addresses another problem.

That change concerns ospf area range summarization, where A fragmented area-address plan and missing ABR inter-area summarization cause avoidable detailed LSAs to propagate. The reported issue instead stems from: A totally stubby or regular stub area cannot originate external LSAs through an internal ASBR in the required manner.

That change concerns ospf external route type choice, where External Type 2 cost behavior does not account for internal cost in the same way as Type 1 when external metrics differ. In this question the necessary remedy is “Design a supported NSSA with correct Type 7 origination and ABR translation handling where needed”, which this alternative does not provide.

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 observed condition is a remote OSPF branch must inject routes from a local non-OSPF process while still limiting external flooding from the rest of the enterprise; this mechanism addresses another problem.

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” would remedy that alternative situation, but it would not correct the present issue: IPv4-only security rules do not automatically enforce the same trust boundary for IPv6 traffic on a dual-stack path.

“Design appropriate NAT64 plus DNS64 service boundaries, DNS behavior and application compatibility exceptions” is the supported response when IPv6-only clients cannot communicate with IPv4-only services without supported translation and suitable destination synthesis. Here the decisive response is “Develop explicit IPv6 security policies for routing, access, logging and required ICMPv6 control behavior”, so that different intervention does not meet the stated requirement.

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” applies to that other condition. The reported evidence is a security design filters outbound IPv4 branch traffic but turns on IPv6 at WAN gateways without corresponding IPv6 ACLs and telemetry; this alternative would address the wrong dependency.

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.