Cisco 300-420 Bundle

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.

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” would remedy that alternative situation, but it would not correct the present issue: IP-prefix ACLs become brittle when identity and endpoint groups move, while fabric policy can use scalable group-based classification.

“Design supported control-plane node redundancy and test endpoint registration continuity during node loss” is the supported response when a single endpoint map/control-plane service is a common-mode availability risk even with redundant data-plane links. Here the decisive response is “Use authorized scalable group tags and matching group-based access policy integrated with the intended identity service”, so that different intervention does not meet the stated requirement.

Security group policy alone may not replace full virtual-network level route isolation where separate macrosegments are required. “Design distinct fabric virtual networks with appropriate external borders and tightly defined shared services” applies to that other condition. The reported evidence is two employee groups must share a fabric virtual network for common application routing but security wants group-based access without maintaining thousands of individual IPv4 ACL entries; this alternative would address the wrong dependency.

Uncoordinated system clocks undermine log chronology, audit correlation and incident reconstruction. “Monitor clock drift and NTP source reachability after management VRF and firewall changes” would remedy that alternative situation, but it would not correct the present issue: multicast RPF typically checks the route back toward the source or RP, not merely whether a receiver destination is reachable.

“Test management service continuity as part of data center disaster recovery rather than only device link redundancy” is the supported response when central monitoring infrastructure can become a single point of failure even when individual access devices have redundant uplinks. Here the decisive response is “Verify RPF interfaces after changing unicast costs or adding asymmetric WAN paths”, so that different intervention does not meet the stated requirement.

Overly aggressive polling can consume limited control-plane CPU and management bandwidth without improving decision quality. “Capacity-test telemetry subscription counts and sampling periods before expanding monitoring fleets” applies to that other condition. The reported evidence is a multicast receiver sees no video even though the router has a unicast route to the receiver, and engineers inspect only destination forwarding; 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: EtherChannel members need compatible Layer 2 settings and negotiated bundling state to represent a correct logical link.

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 “Standardize member configuration and use supported LACP negotiation and consistency checks for the port channel”, which this alternative does not provide.

That change concerns multichassis link peer failure, where A conventional port channel cannot span unrelated independent switches without a supported multichassis or stacking mechanism. The observed condition is an access switch bundles two ports toward a distribution switch but one member carries different VLAN tags and the bundle intermittently drops traffic; this mechanism addresses another problem.

PIM sparse mode forwarding relies on supported multicast routing and receiver membership along the required multicast distribution tree. “Include receiver-driven join tests and group-state verification on every routed multicast hop” would remedy that alternative situation, but it would not correct the present issue: multicast RPF decisions can be sensitive to unicast path selection, including ECMP and asymmetric routing behavior.

“Audit group range ownership and multicast boundary filters whenever a new partner network connects” is the supported response when without explicit multicast boundary control, group advertisements or forwarding may extend beyond authorized trust domains. Here the decisive response is “Verify source-tree RPF after routing metric changes rather than only testing unicast ping”, so that different intervention does not meet the stated requirement.

RP location affects shared-tree path efficiency and control resilience for ASM groups and can create a remote common-mode dependency. “Reevaluate RP placement whenever adding large receiver clusters or relocating content sources” applies to that other condition. The reported evidence is an enterprise adds an equal-cost WAN path and multicast traffic begins failing because the selected upstream RPF path differs from the ingress interface chosen by a source; this alternative would address the wrong dependency.

Multipoint Ethernet services and many independent E-Line circuits have different Layer 2 forwarding and spanning-tree implications. “Document E-Line versus E-LAN service boundaries and operational responsibility with the provider” would remedy that alternative situation, but it would not correct the present issue: a shared provider routing domain cannot preserve independent overlapping tenant address spaces and route targets without isolation.

“Assess broadcast extension failure domains before buying a transparent transport solely to avoid route design” is the supported response when an MPLS Layer 3 VPN routes IP among separated CE networks rather than delivering a transparent Layer 2 Ethernet service. Here the decisive response is “Audit route targets, route distinguishers and provider CE handoff details during onboarding and acquisitions”, 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. “Verify seasonal radio performance and data-cap alarms before relying on cellular as a branch recovery path” applies to that other condition. The reported evidence is an enterprise has many branch customers with overlapping private prefixes and proposes one shared provider IP routing instance for all tenants; this alternative would address the wrong dependency.

Without port security or identity-aware access control, a simple access port may learn multiple endpoint MAC addresses without limitation. “Deploy suitable port security or 802.1X/MAB policies with sensible violation and recovery handling for endpoint types” would remedy that alternative situation, but it would not correct the present issue: ordinary directed and local broadcasts do not automatically cross routed boundaries, so an explicit authorized delivery design is required.

“Calculate endpoint power demand, switch capacity and redundancy margins and choose appropriate power supplies or models” is the supported response when available PoE power budget and per-port capabilities determine whether simultaneous endpoint power requirements can be met. Here the decisive response is “Design secure supported WoL relays, proxy agents or local management distribution rather than exposing unrestricted broadcasts”, so that different intervention does not meet the stated requirement.

A conventional port channel cannot span unrelated independent switches without a supported multichassis or stacking mechanism. “Use a validated multichassis EtherChannel, virtual switching, or routed dual-homing design for platform capabilities” applies to that other condition. The reported evidence 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 alternative would address the wrong dependency.

IS-IS Level 1 operates within an area while Level 2 provides inter-area connectivity and should bound unwanted topology flooding. “Design appropriate Level 1 and Level 2 adjacency placement with resilient L1/L2 border routers and reachable inter-area summaries” would remedy that alternative situation, but it would not correct the present issue: typical Ethernet SLAAC uses /64 interface identifiers and ordinary host autoconfiguration expectations are not met by arbitrary longer access prefixes.

“Plan application-by-application dual-stack readiness including DNS, access controls, routing, management and rollback verification” is the supported response when network dual stacking alone does not add AAAA DNS records, IPv6 listening services, security policy or path validation to existing applications. Here the decisive response is “Allocate /64 prefixes for SLAAC access segments while using more specialized lengths only in supported and justified designs”, so that different intervention does not meet the stated requirement.

Premature use of a partially ready intermediate system can blackhole transit despite apparently formed control-plane neighbors. “Use a supported startup overload-bit or similar transient-transit suppression design until the node is ready to forward” applies to that other condition. The reported evidence is a network designer attempts to conserve an enterprise /48 by assigning IPv6 /80 prefixes to ordinary SLAAC user LANs, then reports that standard hosts fail autoconfiguration; this alternative would address the wrong dependency.

That change concerns BGP local preference primary egress, where AS-path prepending mainly affects remote path selection; outbound path preference within the local AS is commonly controlled with local preference. The reported issue instead stems from: Conventional iBGP full mesh grows quadratically and becomes costly to configure, observe and recover.

That change concerns BGP as path prepending inbound engineering, where Local preference is not exported between autonomous systems, so changing it cannot directly govern external networks' inbound selection. In this question the necessary remedy is “Introduce redundant route reflectors with appropriate client hierarchy and loop-prevention identifiers”, which this alternative does not provide.

That change concerns BGP med neighboring exit choice, where Internal OSPF cost does not communicate an intended interconnect preference to the neighboring autonomous system. The observed condition is an internal BGP deployment expands to twenty routers using full-mesh sessions and new routers are added without a scalable peer plan; this mechanism addresses another problem.

That change concerns rapid spanning tree edge port guard, where Unprotected edge-port fast transition can introduce topology-change or loop risks if another bridge is attached. The reported issue instead stems from: Without deliberate STP root design, Layer 2 forwarding paths may traverse inappropriate access hardware.

That change concerns bfd campus uplink detection, where Carrier detection at the local switch does not necessarily detect loss of a remote routed neighbor or intermediate path. In this question the necessary remedy is “Set primary and backup STP roots on appropriate distribution devices and validate bridge priority and path costs”, which this alternative does not provide.

That change concerns campus virtual switching platform abstraction, where A virtualized or stacked switching design needs supported control, state and multichassis link mechanisms to act as one logical system. The observed condition is a campus has redundant access trunks but an unmanaged access switch wins spanning-tree root after it comes online with an unexpectedly favorable bridge priority; this mechanism addresses another problem.

That change concerns eigrp feasible successor requirements, where An EIGRP feasible successor must satisfy its feasibility condition relative to the successor's feasible distance to prevent loops. The reported issue instead stems from: Unnecessary specific-route propagation increases state and change sensitivity without providing required central policy detail.

That change concerns eigrp authentication mismatched key chain, where Neighbor authentication parameters and permitted key windows must align or the routing protocol rejects peer messages. In this question the necessary remedy is “Apply well-bounded route summaries at distribution interfaces only after validating component networks and discard consequences”, which this alternative does not provide.

That change concerns eigrp unequal cost traffic sharing, where EIGRP unequal-cost load sharing is not enabled simply because multiple routes exist and is constrained by feasibility and variance. The observed condition is a distribution router advertises every tiny branch prefix separately into the EIGRP core even though branches are allocated in contiguous blocks; this mechanism addresses another problem.