Cisco 300-420 Bundle

In-band-only management can share a fault with the network being repaired, eliminating the ability to recover remotely. “Provide secure out-of-band management through independent transport, power and authentication suitable for critical nodes” would remedy that alternative situation, but it would not correct the present issue: legacy community strings do not provide SNMPv3's user-based authentication and encryption capabilities needed by the policy.

“Design redundant remote syslog collectors with protected transport, appropriate facilities and retention controls” is the supported response when local log storage and rollover cannot substitute for reliable centralized timestamped security event retention. Here the decisive response is “Design supported SNMPv3 users, auth/privacy mechanisms, least-privilege views and central credential lifecycle”, so that different intervention does not meet the stated requirement.

A common routing table broadens the management attack surface and increases risk of route or ACL leakage. “Create a supported management VRF or equivalent separated context and tightly controlled shared services as needed” applies to that other condition. The reported evidence 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 alternative would address the wrong dependency.

That change concerns campus poe power budgeting, where Available PoE power budget and per-port capabilities determine whether simultaneous endpoint power requirements can be met. The reported issue instead stems from: Ordinary directed and local broadcasts do not automatically cross routed boundaries, so an explicit authorized delivery design is required.

That change concerns campus port security mac limit, where Without port security or identity-aware access control, a simple access port may learn multiple endpoint MAC addresses without limitation. In this question the necessary remedy is “Design secure supported WoL relays, proxy agents or local management distribution rather than exposing unrestricted broadcasts”, which this alternative does not provide.

That change concerns lacp etherchannel member consistency, where EtherChannel members need compatible Layer 2 settings and negotiated bundling state to represent a correct logical link. The observed condition is an enterprise wants remote Wake-on-LAN for sleeping workstations in many VLANs but the management tool sends only local Ethernet magic packets from a central server; this mechanism addresses another problem.

OpenConfig provides vendor-neutral model definitions whose implemented paths and capabilities must still be validated per platform. “Select supported OpenConfig telemetry modules, verify revisions and normalize exceptions without assuming universal coverage” would remedy that alternative situation, but it would not correct the present issue: vendor-native data models may expose platform-specific schema that cannot be queried identically across different vendors.

“Read supported YANG module revisions and capabilities and implement controlled schema compatibility or versioned adapters” is the supported response when machine-readable data model revisions and capabilities can differ across platform versions even if management connectivity remains healthy. Here the decisive response is “Prefer a suitable standards-based IETF model for portable interface telemetry, documenting implementation gaps and vendor extensions”, so that different intervention does not meet the stated requirement.

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” applies to that other condition. The reported evidence is a national enterprise must collect interface statistics from routers supplied by three vendors, but a developer builds everything against one Cisco-proprietary YANG path; 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. “Implement supported IS-IS IPv6 reachability with interface family configuration and consistent topology preferences” would remedy that alternative situation, but it would not correct the present issue: mixed or unsuitable metric styles can undermine consistent path-cost planning and overflow the intended metric range.

“Advertise summaries only with valid downstream coverage or an explicitly documented safe discard and failover behavior” is the supported response when summary advertisement can attract destinations no longer reachable through the summarizing area, creating a predictable blackhole. Here the decisive response is “Standardize supported wide-metric design and audit interface cost policies across participating IS-IS devices”, so that different intervention does not meet the stated requirement.

An unprotected adjacency trust boundary can admit unauthorized IS-IS control messages into a routing domain. “Deploy supported IS-IS authentication with coordinated algorithms and keys and restrict peers to intended segments” applies to that other condition. The reported evidence is an enterprise upgrades IS-IS for high-capacity links but one region still relies on incompatible metric expectations, producing unintended path preference for long WAN circuits; 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: carrier detection at the local switch does not necessarily detect loss of a remote routed neighbor or intermediate path.

“Select a validated stacking or virtual-switch architecture and plan supervisor, interconnect and software compatibility” is the supported response when a virtualized or stacked switching design needs supported control, state and multichassis link mechanisms to act as one logical system. Here the decisive response is “Design suitable BFD sessions for supported routing peers with conservative scale-aware timer settings”, so that different intervention does not meet the stated requirement.

Without deliberate STP root design, Layer 2 forwarding paths may traverse inappropriate access hardware. “Set primary and backup STP roots on appropriate distribution devices and validate bridge priority and path costs” applies to that other condition. The reported evidence is a distribution-to-core Ethernet link stays administratively up while a transport device in the middle fails, and routing reconverges only after slow protocol timeouts; this alternative would address the wrong dependency.

A BGP TCP session does not automatically negotiate or advertise every address family without appropriate capabilities and policy. “Enable intended IPv6 unicast AFI/SAFI activation, reachable next hops and export filtering consistently on peers” would remedy that alternative situation, but it would not correct the present issue: unrestricted BGP export policy exposes destinations not authorized for upstream announcement and risks routing leaks.

“Use supported point-to-point OSPF network type consistently on both sides where the physical design permits” is the supported response when default broadcast OSPF network behavior can elect designated routers even when the topology is only a two-router link. Here the decisive response is “Apply explicit approved outbound prefix filters at the eBGP boundary and validate maximum prefix expectations”, so that different intervention does not meet the stated requirement.

Layer 1 carrier state may not reveal a downstream path failure and slow neighbor detection extends blackhole time. “Deploy supported BFD for the intended OSPF peers, validate timers against platform capacity and test false-positive risk” applies to that other condition. The reported evidence is a branch BGP edge learns a public provider default plus private corporate specifics and accidentally advertises internal /24s back to the provider; this alternative would address the wrong dependency.

A purely hub-and-spoke forwarding policy can add latency and load when the DMVPN design is intended to allow direct spoke shortcuts. “Validate dynamic tunnel establishment and hub policy under branch renumbering and failover” would remedy that alternative situation, but it would not correct the present issue: an encrypted Internet overlay does not provide the same private carrier connectivity, SLA and traffic-engineering options as a qualified dedicated cloud circuit.

“Separate tunnel encapsulation requirements from cryptographic protection during design reviews” is the supported response when GRE provides encapsulation for multiple protocols but does not itself encrypt or authenticate payload confidentiality. Here the decisive response is “Document cloud provider port limits, routing policies and redundancy across independent interconnect facilities”, so that different intervention does not meet the stated requirement.

Dynamic spoke resolution needs correct NHRP network ID, authentication, hub mapping and reachable tunnel source rather than only a live Internet connection. “Check dynamic public IP and NAT dependencies during DMVPN branch modem replacements” applies to that other condition. The reported evidence is a regulated enterprise runs latency-sensitive cloud workloads but routes all traffic through a public Internet VPN and needs predictable private provider connectivity; this alternative would address the wrong dependency.

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” would remedy that alternative situation, but it would not correct the present issue: overlay headers reduce usable path MTU and blocked ICMPv6 Packet Too Big feedback can prevent Path MTU Discovery.

“Select native dual stack for capable segments and reserve translation for real IPv4-only boundaries with documented requirements” is the supported response when translation adds stateful dependencies and application edge cases that may be unnecessary when a controlled native dual-stack phase is viable. Here the decisive response is “Budget tunnel overhead in MTU planning, preserve required ICMPv6 control messages and validate endpoints' segment sizes”, 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. “Develop explicit IPv6 security policies for routing, access, logging and required ICMPv6 control behavior” applies to that other condition. The reported evidence is a dual-stack application works with small IPv6 probes through a GRE overlay but stalls on larger encrypted payloads after tunnel encapsulation; this alternative would address the wrong dependency.

Uncontrolled multihoming can select unpredictable exits and cause asymmetry or suboptimal paths under provider changes. “Define local preference, inbound announcement policy and health tracking based on primary and backup business requirements” would remedy that alternative situation, but it would not correct the present issue: service encapsulation consumes transport overhead and can exceed an underlay MTU that was sized only for native Ethernet payloads.

“Use a security-enforcing hub design or distributed inspection architecture with explicit policy for branch-to-branch traffic” is the supported response when shortcut VPN topology changes can bypass required inspection if the WAN policy assumes every flow transits a central hub. Here the decisive response is “Negotiate and implement supported provider service MTU and customer handoff frame sizes including encapsulation requirements”, so that different intervention does not meet the stated requirement.

Local interface carrier may remain up when upstream service fails, so a static route without health tracking can blackhole traffic. “Use supported service probing and tracked next-hop or routing convergence to withdraw an unusable primary path” applies to that other condition. The reported evidence is a provider delivers a Layer 2 VPN between sites with 1500-byte host payloads, but an extra service label and VLAN tag causes dropped frames in one segment; this alternative would address the wrong dependency.

EtherChannel members need compatible Layer 2 settings and negotiated bundling state to represent a correct logical link. “Standardize member configuration and use supported LACP negotiation and consistency checks for the port channel” would remedy that alternative situation, but it would not correct the present issue: without port security or identity-aware access control, a simple access port may learn multiple endpoint MAC addresses without limitation.

“Use a validated multichassis EtherChannel, virtual switching, or routed dual-homing design for platform capabilities” is the supported response when a conventional port channel cannot span unrelated independent switches without a supported multichassis or stacking mechanism. Here the decisive response is “Deploy suitable port security or 802.1X/MAB policies with sensible violation and recovery handling for endpoint types”, so that different intervention does not meet the stated requirement.

Ordinary directed and local broadcasts do not automatically cross routed boundaries, so an explicit authorized delivery design is required. “Design secure supported WoL relays, proxy agents or local management distribution rather than exposing unrestricted broadcasts” applies to that other condition. The reported evidence is a user port should admit one registered device but an unmanaged bridge with several MAC addresses is connected, and the switch admits all sources; this alternative would address the wrong dependency.