Pass the Cisco CCNP Enterprise 300-420 Questions and answers with Dumpstech

The verifying get-config reply must reflect the same YANG model hierarchy and configured values that were pushed by the Postman request. In model-driven automation, a successful transport response is not enough; the engineer must confirm that the intended datastore contains the exact interface, routing, or protocol objects described by the model. Option D is the selected reply because it matches the expected YANG structure for the configuration operation shown in the exhibit. The key principle is that get-config returns configuration data from a specified datastore, such as running or candidate, using the schema-defined XML hierarchy. If the returned XML uses the wrong container, wrong namespace, incorrect key value, or an unexpected leaf, the model set was not designed or addressed correctly. Cisco NETCONF/YANG workflows rely on strict namespace and path accuracy, so even a small mismatch can result in configuration being placed in the wrong subtree or not applied. A clean validation checks the model namespace, parent containers, list keys, leaf names, and actual configured value. Reference topics: NETCONF get-config, YANG XML encoding, datastore validation, Postman automation workflow.

LFA FRR is the correct improvement because it gives OSPF a precomputed repair path instead of waiting for normal SPF reconvergence after a component failure. Cisco describes OSPF LFA Fast Reroute as using a precomputed alternate next hop to reduce failure reaction time when the primary next hop fails. The forwarding plane can move traffic to the alternate path while the control plane reconverges, which directly addresses the short outage described in the question. Incremental SPF reduces CPU impact by recomputing only the affected part of the SPF tree, but it still relies on the post-failure SPF process. BFD detects a failure quickly, but by itself it does not install a loop-free repair path. Aggressive timers also improve detection but increase control-plane sensitivity and do not provide local repair. In an enterprise OSPF design where the complaint is outage during recomputation, LFA FRR is the stronger availability mechanism. Reference topics: OSPF Loop-Free Alternate, IP Fast Reroute, SPF convergence, local repair paths, routed resiliency.

The OSPF design should include LSA/SPF timer tuning and summarization with appropriate stub-area design. Cisco OSPF convergence is affected by failure detection, LSA generation, flooding, SPF scheduling, and routing-table installation. Tuning LSA and SPF throttling timers helps the network react quickly to genuine failures while avoiding excessive CPU churn during repeated flaps. This is especially important when voice and video traffic are sensitive to convergence delay. Manual route summarization at area boundaries reduces the number of detailed routes advertised between areas and limits the blast radius of link failures. Configuring nonbackbone areas as stub networks where appropriate also reduces external LSA propagation and lowers router resource use. Reducing DR and BDR election frequency is not a primary design tool for convergence, and increasing hello and hold timers would slow failure detection rather than improve it. Advertising default routes can be useful, but it does not by itself contain link flap impact. Reference topics: OSPF area design, LSA throttling, SPF throttling, route summarization, stub areas, convergence optimization.

A /22 subnet is the smallest IPv4 block in the answer set that closely fits a branch expected not to exceed roughly one thousand users while avoiding unnecessary address waste. A /22 contains 1024 total addresses and 1022 usable host addresses after the network and broadcast addresses are reserved. That aligns with the requirement to provide the maximum number of host addresses without selecting a larger block than necessary. A /21 provides 2048 total addresses and 2046 usable hosts, which is materially larger than the stated requirement and wastes address space. The specific 192.168.8.0/22 block also aligns on a valid /22 boundary because /22 networks increment by four in the third octet. A 192.168.16.0/22 is also mathematically valid, but the exhibit determines the available address range; the selected option uses the appropriate block from the displayed plan. Reference topics: IPv4 subnet sizing, CIDR, usable host calculation, branch address planning, VLSM.

The Cisco SD-Access edge node acts as the access-layer fabric device that connects endpoints to the fabric, provides the anycast Layer 3 gateway, and maps users or endpoints into the correct virtual network. Cisco SD-Access fabric edges register endpoint information with the control-plane node and encapsulate user traffic into VXLAN for transport across the fabric. The anycast gateway function allows a consistent default gateway to exist on multiple edge nodes, supporting mobility without forcing traffic through a central gateway. The edge node also applies policy context by associating users, endpoints, or ports with a virtual network and scalable group information. Advertising EID subnets is primarily associated with border connectivity and external route advertisement. LISP proxy tunnel router functionality belongs to border node behavior for external connectivity. Routing and transporting IP packets between fabric nodes is the intermediate-node underlay role. Therefore, the two edge-node functions in the options are acting as the anycast Layer 3 gateway and mapping users to virtual networks. Reference topics: SD-Access edge node, anycast gateway, endpoint registration, virtual networks, fabric policy.

L2VPN is the correct technology because the requirement is for two remote offices to share a common broadcast domain across a private WAN with minimal overhead. A Layer 2 VPN service extends Ethernet or VLAN connectivity between customer sites while keeping the customer routing design independent of the provider core. From the customer perspective, the two sites can appear to be on the same Layer 2 segment, which satisfies the shared broadcast-domain requirement. GET VPN, IPsec, and GRE are Layer 3-oriented technologies. They can connect sites securely or provide tunneling, but they do not natively create a common Layer 2 broadcast domain between the offices. GRE also adds additional encapsulation overhead, and IPsec alone generally provides encrypted routed connectivity rather than an Ethernet service. For a simple direct logical path over a private WAN, an L2VPN service such as VPWS or VPLS is the appropriate design family. Reference topics: L2VPN, VPWS, VPLS, Ethernet WAN services, broadcast-domain extension, private WAN connectivity.

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.

Dual stack is the migration topology that supports IPv6 while preserving existing IPv4 services during the transition. In a dual-stack design, hosts and network devices run IPv4 and IPv6 in parallel, allowing applications and services to move gradually from IPv4 to IPv6 without forcing an immediate cutover. That matches the customer’s plan: keep the current IPv4 topology and services, introduce IPv6 connectivity, migrate services, and eventually decommission the IPv4 topology. 6VPE is used to carry IPv6 VPN routes across an MPLS IPv4 provider core, which is a service-provider VPN use case rather than a general enterprise migration topology. 6to4 is an automatic tunneling mechanism and is not appropriate as a stable enterprise migration plan. NAT64 enables IPv6-only clients to reach IPv4 resources through translation, but it does not preserve the complete IPv4 topology while services migrate. Cisco migration guidance treats dual stack as the cleanest operational model when infrastructure supports both protocols, because it avoids translation side effects and allows DNS and application behavior to determine which protocol is used.

Service routes in OMP updates identify services that are available for centralized service insertion. In Cisco Catalyst SD-WAN, OMP does more than advertise ordinary VPN prefixes. It also carries TLOC routes, which describe transport locators, and service routes, which allow the fabric to steer traffic toward network services such as firewalls, intrusion prevention systems, or other centralized service nodes. This is how the SD-WAN control plane distributes enough information for WAN Edge routers to make policy-driven forwarding decisions without requiring each device to learn service attachment through a separate routing protocol. A service route is not used to describe the underlay transport itself, because that function is handled by TLOC information. It is also not a route to the orchestration plane or a remote management definition. The design value is that service insertion can be centrally advertised and controlled through OMP, then applied consistently through SD-WAN policy. Reference topics: Cisco SD-WAN OMP, service routes, TLOC routes, service insertion, centralized data policy.

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.