Sure Pass Exam 300-420 PDF

Affinity is the Cisco SD-WAN feature used to minimize TLOC and control connections and reduce strain on vSmart controllers. Cisco documentation explains that establishing affinity between controllers and edge devices allows the operator to control overlay scaling by limiting which controllers an edge device can establish control connections with. In large deployments, unrestricted connections between every WAN Edge and every controller can create unnecessary state and operational load. Affinity lets the design distribute edge connections across controllers and data centers while still preserving redundancy through primary and backup controller relationships. Color identifies the transport type or behavior associated with a TLOC, but it does not reduce controller connection scale by itself. Control-direction and control-connections are not the feature names that provide the scaling function described in the question. A well-designed SD-WAN control plane uses affinity, controller groups, and redundancy planning to keep the overlay scalable and predictable. Reference topics: Cisco SD-WAN affinity, vSmart controller scale, TLOC connections, control-plane redundancy, overlay scaling.

The Cisco SD-Access data plane is based on VXLAN. Cisco SD-Access separates the fabric into functional planes: the underlay provides IP reachability, the control plane uses LISP to map endpoints to locations, and the data plane uses VXLAN encapsulation to carry user traffic across the routed underlay. VXLAN allows the fabric edge node to encapsulate endpoint traffic and forward it through the fabric while preserving virtual network and segmentation information. This is what enables SD-Access to provide Layer 2 and Layer 3 overlay services over a Layer 3 routed transport. OMP is the control-plane protocol for Cisco SD-WAN, not SD-Access. NHRP is associated with DMVPN tunnel resolution. LISP is essential in SD-Access, but its role is endpoint ID to routing locator mapping, not packet encapsulation in the data plane. Therefore, VXLAN is the correct protocol for the SD-Access data plane. Reference topics: SD-Access fabric, VXLAN data plane, LISP control plane, overlay encapsulation, routed underlay.

Cisco SD-WAN WAN Edge devices can be brought into the overlay through automated zero-touch provisioning or through manual bootstrap configuration. Zero-touch provisioning allows a device to discover the SD-WAN controllers and receive the information needed to authenticate and join the overlay with minimal on-site work. This is a core operational benefit of Cisco SD-WAN because branch routers can be shipped to sites and onboarded without a specialist manually building the entire control-plane configuration locally. Manual configuration remains available when ZTP is not used, when the site has special connectivity constraints, or when the administrator needs to stage the router directly. DHCP options and DNS records can help devices learn controller information in some deployment models, but they are not the complete pair of bootstrap methods named for vEdge onboarding. vManage is the management system, not a bootstrap method by itself. Therefore, the correct methods are ZTP and manual configuration. The design should also validate certificates, organization name, system IP, site ID, and transport interface reachability during onboarding.

Route summarization and EIGRP stub routing are the two correct design techniques for a stable and scalable EIGRP deployment. Summarization reduces the number of prefixes advertised upstream, conserves bandwidth and memory, hides route flaps behind the summary boundary, and reduces the size of the EIGRP topology table. Stub routing prevents branch or access devices from being used as transit routers and limits the scope of EIGRP queries. This is critical because uncontrolled EIGRP query propagation can increase convergence time and processing load, especially in larger hierarchical networks. Prefix lists and distribute lists can filter routes, but filtering alone does not provide the same query-boundary and topology-hiding benefits as summarization and stubs. Static redistribution increases complexity and can create loop or policy risks if not controlled with tags and metrics. The question specifically asks to conserve bandwidth, memory, and CPU, prevent suboptimal routing, and avoid unnecessary queries; summarization and stub routing are the direct Cisco design answers. The architect should summarize at hierarchy boundaries and configure access or branch routers as EIGRP stubs where they should not provide transit. Reference topics: EIGRP summarization, EIGRP stub routing, query scope, hierarchical routing.