Cisco 300-420 Bundle

A single endpoint map/control-plane service is a common-mode availability risk even with redundant data-plane links. “Design supported control-plane node redundancy and test endpoint registration continuity during node loss” would remedy that alternative situation, but it would not correct the present issue: link redundancy within the fabric does not guarantee sufficient external border forwarding capacity during degraded operation.

“Design supported fabric-to-fabric transit via qualified borders and consistent virtual-network route and security policy” is the supported response when physical underlay IP connectivity does not by itself establish appropriate inter-fabric transit, route exchange and segmentation policy. Here the decisive response is “Size border nodes and redundant exits for N-minus-one load, applying failure-domain and traffic-engineering requirements”, 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 a fabric design has redundant edge uplinks but no redundant border capacity, so a single border failure overloads the remaining exit path; this alternative would address the wrong dependency.

OpenConfig provides vendor-neutral model definitions whose implemented paths and capabilities must still be validated per platform. “Version model support matrices and review schema revisions before monitoring-platform upgrades” 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.

“Validate cloud route advertisement, return path and security controls before enabling distributed cloud breakout” is the supported response when traditional centralized route topology can add delay and consume backbone capacity even when local cloud on-ramp options are available. Here the decisive response is “Monitor certificate expiration and automate approved renewal across telemetry collectors and devices”, so that different intervention does not meet the stated requirement.

Logical network separation on one physical direct-connect facility does not eliminate common power, provider or meet-me-room failures. “Review provider location and device diversity rather than treating two logical virtual interfaces as two physical links” 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.

Naive replicated unicast can consume far more shared-link capacity than a suitable multicast tree for many receivers. “Assess multicast replication at branching points or other supported content distribution design with receiver policy” 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.

“Align multicast source reachability and acceptable RPF design with supported ECMP handling and stable upstream selection” 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 “Enable appropriate PIM and IGMP behavior on intended routed interfaces and validate RP and RPF reachability”, 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. “Apply supported multicast group or source boundary filtering at the appropriate WAN and tenant interfaces” 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 endpoint map/control-plane service is a common-mode availability risk even with redundant data-plane links. “Design supported control-plane node redundancy and test endpoint registration continuity during node loss” would remedy that alternative situation, but it would not correct the present issue: identity group classification requires a trusted policy source and onboarding process rather than arbitrary address-based role guessing.

“Use authorized scalable group tags and matching group-based access policy integrated with the intended identity service” is the supported response when IP-prefix ACLs become brittle when identity and endpoint groups move, while fabric policy can use scalable group-based classification. Here the decisive response is “Integrate the fabric with appropriate Cisco ISE identity policy and validated endpoint profiling or authentication flows”, so that different intervention does not meet the stated requirement.

Fabric overlay multicast support and replication design have specific control and data-plane requirements beyond simple underlay multicast reachability. “Select a supported SD-Access multicast forwarding model and test receivers across fabric edges and virtual networks” applies to that other condition. The reported evidence is a design team enables fabric segmentation but never integrates network-access authentication and group assignment, assuming switches infer business roles from host IPs; this alternative would address the wrong dependency.

Unprotected edge-port fast transition can introduce topology-change or loop risks if another bridge is attached. “Apply supported PortFast or edge behavior with BPDU Guard and an approved exception procedure for genuine uplinks” would remedy that alternative situation, but it would not correct the present issue: an SVI routed ACL does not necessarily inspect intra-VLAN switched frames that never reach Layer 3 forwarding.

“Design supported VRF-lite routing instances with carefully governed shared-services connectivity and separate interface assignments” is the supported response when a common routing instance cannot enforce independent overlapping IP destinations and controlled route exposure by itself. Here the decisive response is “Design supported VACL, private VLAN or separate VLAN segmentation according to local traffic patterns and platform capabilities”, so that different intervention does not meet the stated requirement.

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

Gateway role restoration depends on the selected FHRP protocol and its configured preemption settings, not priority numbers alone. “Choose a documented VRRP preemption design with safe delay and reachability tracking that fits service stability goals” would remedy that alternative situation, but it would not correct the present issue: FHRP presence alone may not account for upstream path viability without appropriate object or interface tracking.

“Restore approved VLAN trunk reachability and compatible HSRP group and timer settings across both devices” is the supported response when FHRP peers must exchange control messages in a correctly shared VLAN to maintain a single active forwarding role. Here the decisive response is “Track the required upstream path and decrement priority enough for a healthy standby gateway to assume forwarding”, so that different intervention does not meet the stated requirement.

Traditional active-standby first-hop redundancy does not by itself provide the desired per-client gateway load distribution. “Consider GLBP where supported or a different routed access and anycast design, based on platform capability and operational needs” applies to that other condition. The reported evidence is a campus HSRP active router loses its WAN uplink but keeps its local VLAN interface up, so users keep sending packets to a gateway that cannot exit the site; this alternative would address the wrong dependency.

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” would remedy that alternative situation, but it would not correct the present issue: manual per-prefix policy misses newly onboarded routes when attributes and export rules are not centrally classified.

“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 “Tag routes with an approved community scheme and enforce explicit export policy at each boundary”, so that different intervention does not meet the stated requirement.

BGP additional paths must satisfy supported multipath eligibility rules and configured maximum-path policy to share traffic. “Evaluate path attributes and supported multipath settings, then choose a design that preserves deterministic failover” applies to that other condition. The reported evidence is an enterprise requires certain partner routes never to be announced to public Internet peers but currently filters using manually maintained individual prefixes only; this alternative would address the wrong dependency.

Management availability and existing data-plane forwarding have different dependencies, while loss of manageability remains an operational risk. “Design redundant supported SD-WAN Managers with backup, RBAC and regional management reachability as appropriate” would remedy that alternative situation, but it would not correct the present issue: traditional point-to-point encryption tunnel meshes may add unnecessary topology and scale complexity for a trusted private routed underlay.

“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 “Evaluate supported GET VPN group key distribution and policy design where technology and business requirements fit”, 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 a corporate private MPLS WAN needs IP payload confidentiality across many sites without forcing ordinary site-to-site traffic through a tunnel hub; this alternative would address the wrong dependency.

Standardized models do not necessarily represent every vendor-specific operational or configuration feature. “Use the supported Cisco native YANG model for the particular feature with platform and software-version capability checks” 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.

“Prefer a suitable standards-based IETF model for portable interface telemetry, documenting implementation gaps and vendor extensions” 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 “Read supported YANG module revisions and capabilities and implement controlled schema compatibility or versioned adapters”, so that different intervention does not meet the stated requirement.

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” 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.

IBGP typically preserves the external next hop, which must be reachable through the internal routing infrastructure. “Provide appropriate next-hop-self policy or valid internal reachability for external BGP next hops with loop-free forwarding” would remedy that alternative situation, but it would not correct the present issue: randomly scattered branch subnets prevent region-level summarization and make routing and change control unnecessarily complex.

“Create aligned aggregates that cover actual component prefixes and validate binary prefix boundaries and the destination routing behavior” is the supported response when a /15 covers two consecutive aligned /16 networks and the selected /15 omits 10.66.0.0/16 while including unintended space. Here the decisive response is “Reserve contiguous region-sized address blocks, allocate branch VLSM prefixes inside each block and summarize only reachable ranges at distribution boundaries”, so that different intervention does not meet the stated requirement.

An IPv4 /27 ordinarily has only thirty usable host addresses, so it cannot accommodate the stated phones and gateway. “Allocate a suitably sized /25 or larger subnet after accounting for network, broadcast, gateway and expected device growth” applies to that other condition. The reported evidence is a company has thirty branches that each receive random /24 networks from a central /16. It needs regional route aggregation, predictable expansion and simpler access policies without renumbering annually; this alternative would address the wrong dependency.

That change concerns site to site vpn hub hairpin inspection, where Shortcut VPN topology changes can bypass required inspection if the WAN policy assumes every flow transits a central hub. The reported issue instead stems from: Management availability and existing data-plane forwarding have different dependencies, while loss of manageability remains an operational risk.

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 “Design redundant supported SD-WAN Managers with backup, RBAC and regional management reachability as appropriate”, which this alternative does not provide.

That change concerns cisco sd wan management and data path separation, where Using only the affected data-plane overlay for operational access can eliminate remote troubleshooting when the fabric fails. The observed condition is an enterprise relies on a single remote management platform for all SD-WAN configuration and assumes controller outage is equivalent to immediate edge forwarding loss; this mechanism addresses another problem.