The company must configure a summary route on R1. The branch routers must remain normal EIGRP routers, and auto-summary is not allowed, so the scalable design choice is manual summarization at the hub. Cisco EIGRP documentation states that manual summarization can be configured on an interface using the ip summary-address eigrp command and can summarize routes on almost any bit boundary. In a DMVPN hub-and-spoke topology, a hub summary reduces the number of individual routes advertised to branches, limits routing-table growth, and helps contain EIGRP queries. It also keeps branch configuration simple because the branches do not need to be converted to stub routers to meet this specific requirement. Disabling split horizon is a common DMVPN Phase 2 consideration when the hub must advertise spoke routes back out the same multipoint tunnel interface, but it does not summarize HQ routes. A multipoint interface is already implied by DMVPN, and disabling the SIA timer is not a design solution. Reference topics: EIGRP manual summarization, DMVPN hub design, no auto-summary, query containment.

The VPN drag-and-drop answer distinguishes Layer 2 VPN, Layer 3 VPN, and encrypted overlay VPN behavior. VPWS provides a point-to-point Layer 2 service, while VPLS provides multipoint Layer 2 Ethernet service across a provider core. MPLS Layer 3 VPN provides routed private WAN connectivity with provider-managed VPN routing and forwarding separation. GRE and DMVPN are overlay technologies that can carry multicast and dynamic routing protocols; DMVPN adds NHRP and multipoint GRE to scale hub-and-spoke and spoke-to-spoke designs. IPsec provides encryption and integrity for traffic over untrusted transport, but native policy-based IPsec does not carry multicast without an additional overlay such as GRE. GET VPN encrypts traffic across a private routed WAN without building permanent point-to-point tunnels and is often used where multicast and dynamic routing should remain visible to the transport. The selected mapping aligns each VPN type with its forwarding model, scale characteristics, and encryption behavior. In design, the correct VPN choice depends on whether the requirement is Layer 2 extension, routed private connectivity, dynamic spoke-to-spoke tunnels, or private WAN encryption. Reference topics: VPN design, VPLS, VPWS, DMVPN, IPsec, GET VPN.

When Cisco SD-WAN edge router redundancy is designed, VRRP is the supported first-hop redundancy protocol in the SD-WAN edge context. VRRP provides a virtual default gateway for LAN-side devices, allowing one WAN Edge router to act as the active gateway while another can take over if the active router or tracked condition fails. Cisco SD-WAN designs use VRRP with tracking and policy alignment so branch LAN traffic can fail over to the appropriate edge router while the SD-WAN overlay handles transport and tunnel selection. HSRP and GLBP are traditional campus first-hop redundancy protocols, but they are not the supported FHRP answer for vEdge router redundancy in this design context. OMP is the SD-WAN control-plane routing protocol used between WAN Edge routers and vSmart controllers; it is not a first-hop redundancy protocol for LAN hosts. Therefore, the correct FHRP for vEdge router redundancy is VRRP. The design should also ensure that VRRP priorities, tracking, and SD-WAN routing preferences align so traffic exits the intended edge during normal and failure conditions.

The design must influence how EIGRP-learned routes are injected into the OSPF domain, so R2 should redistribute EIGRP into OSPF as metric-type E1 and R3 as metric-type E2. Cisco OSPF documentation distinguishes external Type 1 and Type 2 routes. An E1 route includes the external cost plus the internal OSPF cost to reach the ASBR, while an E2 route uses only the external metric. Cisco path selection prefers O E1 over O E2 for the same external destination. Therefore, making R2 advertise the EIGRP routes as E1 causes OSPF routers to prefer R2 as the exit toward the EIGRP domain. Option C adjusts OSPF-to-EIGRP redistribution, which is the wrong direction for traffic passing toward EIGRP from OSPF. Removing redistribution on R3 would reduce redundancy. Option D reverses the preference and would favor R3. Reference topics: OSPF external route types, EIGRP-to-OSPF redistribution, ASBR preference, E1 versus E2 metrics.

Locator/ID Separation Protocol is the control-plane technology that allows endpoint identity to be separated from endpoint location. In Cisco SD-Access, LISP is used by the fabric control plane to map endpoint identifiers to routing locators, so an endpoint subnet can remain logically consistent even when endpoint reachability is provided from different network locations. This is why LISP is associated with host mobility and with designs where the same subnet or endpoint identity can exist across multiple places without forcing the physical topology to be a single stretched Layer 2 domain. VXLAN is the data-plane encapsulation used to carry overlay traffic, but VXLAN itself is not the mapping control plane. FabricPath is a Cisco Layer 2 multipath technology and does not provide LISP-style endpoint-location mapping. ISE mobility services are identity and policy functions, not a routing locator mapping system. Therefore, the correct control-plane technology is LISP. Cisco SD-Access design material describes the control plane as the mapping system that maintains endpoint-to-device relationships.

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.

The SD-Access control-plane node maintains the endpoint database and resolves mappings between endpoints and the fabric edge nodes where those endpoints are located. Cisco SD-Access uses LISP in the fabric control plane. Edge nodes register endpoint identifiers with the control-plane node, and other fabric nodes query the control plane when they need to locate a destination endpoint. This control-plane function is commonly described through LISP Map-Server and Map-Resolver behavior. Option B is not correct because endpoint detection occurs at the edge node, not at the control-plane node. The edge is the device connected to users, access points, or endpoint-facing networks, so it learns local endpoint presence and registers that information. Option C refers to authentication and identity, which is integrated with Cisco ISE. Option D describes the border-node role, because border nodes connect the fabric to external networks. The corrected answer is therefore A. A stable SD-Access design must provide redundant control-plane reachability and scale the control-plane role according to fabric size, mobility, and endpoint churn. Reference topics: SD-Access control plane, LISP Map-Server, LISP Map-Resolver, endpoint-to-location mapping.

The two practical OSPF convergence improvements are enabling Bidirectional Forwarding Detection and tuning OSPF timers and throttling behavior. Cisco describes BFD as a protocol designed to provide fast forwarding-path failure detection across media, encapsulations, topologies, and routing protocols. With OSPF, BFD allows a neighbor failure to be detected rapidly without depending only on the OSPF dead interval. OSPF parameters can also be tuned, including SPF scheduling, LSA generation, and LSA arrival throttling, so the control plane reacts quickly but not recklessly during instability. Merging all areas into one backbone area is not a convergence improvement; it usually increases the size of the link-state database and the impact of topology changes. Making every nonbackbone area stub may reduce external LSA scope, but it is not universally valid and does not directly solve failure detection. Spanning the same IP network across multiple OSPF areas is a poor design and can create operational ambiguity. Therefore, BFD plus careful OSPF parameter tuning are the appropriate convergence-focused design actions.

The correct model is a 4-class QoS strategy with DiffServ. The traffic classes listed in the question are explicitly DiffServ per-hop behaviors: Expedited Forwarding for conversational traffic, Assured Forwarding class 2 for streaming, and Assured Forwarding class 3 for web or interactive traffic. Cisco QoS guidance uses DiffServ to classify and mark traffic with DSCP values, then apply per-hop behavior at each node along the path. This gives scalable end-to-end treatment across a provider backbone without maintaining per-flow reservations. The four service treatments implied are conversational, streaming, interactive/web, and background or best effort, which matches the stated service categories without unnecessary class expansion. IntServ is not appropriate for an ISP backbone because it uses RSVP-style per-flow signaling and state, which scales poorly compared with DiffServ PHB handling. The 8-class and 12-class options add complexity beyond the stated mappings. Reference topics: DiffServ, DSCP, EF, AF2, AF3, per-hop behavior, provider QoS design.

OSPF with stub areas is the correct implementation. The reference to RFC 5340 points to OSPFv3, which Cisco documents as the OSPF version used for IPv6 and also capable of carrying IPv4 unicast address families in modern implementations. OSPF is a link-state routing protocol that provides loop-free convergence through SPF calculation, making it a stronger fit than static routing or RIP for a growing WAN. Stub areas reduce routing information inside branch or regional areas by blocking external LSAs and allowing the ABR to inject a default route. That reduces route-table size and limits update propagation, which matches the requirement to optimize routing tables and reduce routing updates between routers. EIGRP with multiple autonomous systems is not aligned with RFC 5340. BGP address families are useful in provider and MPLS VPN designs but are not the best internal route-optimization answer here. OMP is specific to Cisco SD-WAN, not a generic RFC 5340 routing design. Reference topics: OSPFv3, RFC 5340, stub areas, LSA reduction, SPF convergence.