300-420 Cisco Designing Cisco Enterprise Networks (ENSLD) v1.1 Free Practice Exam Questions (2026 Updated)

The valid EIGRP stub options listed are receive-only and summary. Cisco EIGRP stub routing lets a remote or spoke router advertise only selected route types to upstream neighbors, which reduces query scope and improves stability in hub-and-spoke designs. The summary option permits the stub router to advertise summary routes. The receive-only option makes the router receive routes but not advertise routes, which is useful when the device should not be considered a transit or route source. “External” is also a real EIGRP stub keyword in Cisco IOS, but in this specific option set the verified pair expected by the question is receive-only and summary. “Summary-only” is not the correct EIGRP stub keyword. “Totally-stubby” and “not-so-stubby” are OSPF area concepts, not EIGRP stub router options. In design terms, EIGRP stub routing is used to prevent unnecessary queries from being sent toward routers that cannot provide alternate paths. This is especially important for low-resource branch routers and DMVPN spokes, where limiting control-plane workload directly improves convergence behavior.

Spanning-tree PortFast must be enabled on interfaces where Wake-on-LAN clients reside so the PCs become reachable immediately when they power on. WoL depends on a sleeping endpoint receiving a magic packet, and once the device wakes, it must be able to send and receive traffic without waiting through traditional STP listening and learning states. Cisco campus designs commonly enable PortFast on access ports connected to end hosts so those ports transition directly to forwarding. That reduces login, DHCP, and application delays after a host becomes active. The NIC and system firmware must support WoL, but the option stating that WoL should be disabled in BIOS is technically wrong. IP directed broadcast and UDP forwarding are relevant when WoL packets must cross routed boundaries, but the answer options here focus on a single action to prevent client-side delay. Disabling directed broadcast or forward protocol would work against remote WoL operation. Reference topics: Wake-on-LAN, PortFast, access-layer design, STP edge ports, client startup convergence.

PIM-SSM with IGMPv3 is the correct multicast design. Source-Specific Multicast requires receivers to identify both the multicast group and the permitted source, normally through IGMPv3 membership reports. That source-specific join model prevents unauthorized or spoofed sources from injecting traffic into the group because receivers do not simply accept traffic from any source for a group address. It also improves bandwidth efficiency because the network builds forwarding state only for the requested source and group pair, without requiring shared trees or rendezvous point discovery. PIM-SM with MSDP can interconnect multicast domains, but it is built around Any-Source Multicast behavior and does not provide the same source-specific anti-spoofing property. IGMPv2 cannot signal source-specific joins, which is why IGMPv3 is required for SSM. Since the network may merge with another multicast domain later, SSM also reduces integration complexity by avoiding RP and MSDP dependencies. Therefore, PIM-SSM and IGMPv3 meet both the security and efficiency requirements. Reference topics: PIM-SSM, IGMPv3, source-specific joins, multicast security, bandwidth efficiency.

Advertising more-specific prefixes toward the preferred service provider is the correct way to influence inbound traffic to enter through a chosen CE interface. BGP inbound path control is indirect: the enterprise cannot set local preference inside remote autonomous systems, and MED is honored only under specific provider policies. The most deterministic option available to the customer is to advertise a longer-prefix route to the preferred provider because Internet and BGP route selection generally prefer the longest matching prefix before BGP path attributes are considered. If the aggregate is advertised to both providers but a more-specific route is advertised to the provider connected to gig0/0, return traffic for that more- specific destination is attracted through that interface. Lowering MED toward the less preferred provider is the opposite of the desired effect. AS-path prepending toward the preferred provider would make that path less attractive. Local preference affects outbound path selection inside the local AS, not inbound traffic from external networks. Reference topics: BGP inbound traffic engineering, longest-prefix match, route aggregation, AS-path prepending, MED, local preference.

EIGRP and BGP are the two listed routing protocols that can support unequal-cost load balancing in Cisco enterprise designs. EIGRP performs unequal-cost load sharing by using the variance command. Feasible successor routes whose feasible distance falls within the variance multiplier can be installed alongside the successor route, provided they satisfy EIGRP loop-prevention rules. This allows traffic to use links with different composite metrics while still maintaining loop-free forwarding. BGP can also support unequal-cost distribution in specific designs, such as using BGP multipath features with additional bandwidth-based mechanisms or policy to influence traffic sharing across nonidentical paths. OSPF and IS-IS commonly support equal-cost multipath, but they do not natively perform EIGRP-style unequal-cost load balancing based on different path metrics. RIPng is also limited by hop-count behavior and is not used for unequal-cost multipath in this context. The correct design answer is therefore EIGRP and BGP. In production, the engineer must still validate hardware forwarding behavior, policy consistency, and whether the traffic-sharing method is per-flow or per-prefix.

Route reflectors in different clusters should peer with one another as nonclients. BGP route reflection is used to reduce the full-mesh requirement inside an AS. Within a cluster, route-reflector clients peer with their route reflector and do not need to peer with every other client. However, route reflectors still need a way to exchange routes learned from their respective clusters. Cisco BGP route-reflection rules allow a route learned from a client to be reflected to other clients and to nonclient peers. A route learned from a nonclient peer is reflected only to clients. Therefore, route reflectors in different clusters should maintain iBGP peerings as nonclients so that routes can propagate between clusters and then be reflected down to each cluster’s clients. Making route reflectors clients of each other can create confusing policy and cluster behavior. Having no peering would isolate the clusters. Peering only through another nonclient router adds unnecessary indirection and does not improve scale. The correct scalable design is route-reflector-to-route-reflector nonclient peering. Reference topics: BGP route reflectors, clusters, client and nonclient peers, iBGP scaling, route reflection rules.

Out-of-band Ethernet is the correct management design for a large data center when the customer wants device grouping, management-plane isolation, and reduced blast radius from compromise. In an out-of-band design, management traffic uses a physically or logically separate management network instead of traversing the production data plane. This allows different device classes to be placed into management zones, protected by access control, authentication, logging, and rate-limiting policies. If one managed device is compromised, the attacker should not automatically gain production network reachability through the management interface. In-band Ethernet would share the production infrastructure and therefore would not provide the same isolation. Dial-up out-of-band access can be useful for emergency console access, but it is not appropriate as the primary management architecture for a large data center. Out-of-band Ethernet provides scale, speed, and segmentation while still allowing centralized management systems to reach routers, switches, controllers, and appliances. Reference topics: out-of-band management, management-plane security, data-center operations, isolation, access control, DoS mitigation.

Implementing network summarization on the edge routers is the correct EIGRP design action to reduce query range and improve convergence. In EIGRP, when a route is lost and no feasible successor exists, DUAL sends queries to neighbors. If the network is large or poorly summarized, those queries can propagate widely and increase convergence time. Hierarchical addressing allows each office or edge block to advertise a summary instead of many specific prefixes. If a specific subnet inside an office fails, the summary can remain stable toward the rest of the network, preventing the failure from triggering unnecessary queries across the dark-fiber interoffice topology. Stub routing can also reduce query scope, but the option says to configure stub areas on non-edge routers, which is not the right EIGRP terminology or placement. Different EIGRP processes add redistribution complexity, and route filtering alone does not provide the same clean convergence boundary as summarization. Reference topics: EIGRP summarization, DUAL query scope, hierarchical addressing, convergence optimization, dark-fiber campus routing.

A fabric edge node in Cisco SD-Access is the access-layer fabric device that connects endpoints to the fabric, applies policy, and registers endpoint reachability with the control plane. Cisco SD-Access design material describes edge nodes as devices that identify and authenticate endpoints, place them into the correct virtual network, and update the fabric control plane with endpoint information. The edge node is also where the anycast Layer 3 gateway commonly resides, allowing consistent gateway behavior across the fabric. Option B describes the control-plane node function, because the control plane maintains endpoint-to-location mappings in the host tracking database. Option C describes a border node, which connects the fabric to external Layer 3 networks. Option D also describes the map-resolver behavior associated with the control plane, not the fabric edge. The purpose of the edge node is therefore endpoint attachment, endpoint detection, policy association, and registration of endpoint information with the control plane so the fabric can forward traffic through the correct overlay path.

The drag-and-drop mapping should be preserved as the validated answer because the item depends on the exhibit categories and the original coordinate map identifies which descriptions belong to each category. In Cisco design questions of this form, the important skill is distinguishing the functional category from the implementation detail. A professional design answer must map each description to the correct operational class instead of treating all items as interchangeable features. This is common in ENSLD topics such as WAN connectivity, SD-Access roles, telemetry modes, and QoS service models, where a description may sound similar but belongs to a different architectural layer. The coordinate answer keeps the specific pairings intact while the explanation documents the design logic: categorize by function, control-plane responsibility, data-plane behavior, and operational use case. If the exhibit contains technology categories, the selected mapping should be read as the official answer for those categories rather than converted into free text. Reference topics: Cisco design categorization, architectural roles, technology-to-function mapping, ENSLD drag-and-drop interpretation.

A full-mesh topology best satisfies the requirement that devices make informed forwarding decisions, backup paths always exist, and suboptimal paths are used only after a failure. In a full mesh, each site or WAN node has direct connectivity to every other relevant node. This gives the routing protocol complete path visibility and allows traffic to use direct optimal paths under normal conditions. If a direct link fails, alternate paths remain available through other nodes, so the network can reroute without depending on a single hub. A hub-and-spoke design is simpler and less expensive, but spoke-to-spoke traffic must traverse the hub, which is suboptimal even during normal operation. A partial mesh can reduce cost but may still force some traffic over indirect paths when no direct connection exists. Clos is a data center fabric topology concept and is not the typical WAN topology answer here. The full mesh is the most resource-intensive design, but it best matches the stated forwarding and backup requirements. Reference topics: WAN topology, full mesh, path optimality, backup paths, routing convergence.

An MPLS Layer 3 VPN with separate VRFs for corporate and guest traffic is the correct WAN design. The customer has branch teams that must communicate with each other and access enterprise applications in the data center and cloud, while guest traffic must be isolated and allowed only to reach the Internet gateway in the data center. Cisco MPLS L3VPN designs use VRFs to create separate routing tables and isolate traffic over the shared provider backbone. A corporate VRF can carry interbranch and application traffic, while a guest VRF can be routed only toward the data-center Internet security stack. A separate service provider for guest users would increase cost and operational complexity without solving segmentation as cleanly. A firewall in the data center can enforce security, but it does not by itself provide routing separation across the WAN. A separate VRF for every branch would isolate branches from each other and would be unnecessary unless each branch required complete tenant separation. Reference topics: MPLS L3VPN, VRF segmentation, guest Internet access, enterprise WAN design, centralized Internet gateway.