300-420 Exam Dumps : Designing Cisco Enterprise Networks (ENSLD) v1.1

The correct overlay considerations are that virtual networks provide data-plane isolation and that overlapping IP addresses should be avoided for operational simplicity. In Cisco SD-Access, virtual networks are used for macro segmentation and are commonly mapped to VRFs. This separates routing and forwarding tables between major groups such as corporate users, guests, IoT, and shared services. Security Group Tags provide finer policy control and microsegmentation, but they are not the primary mechanism for data-plane isolation between virtual networks. The phrase “virtual networks should be used for microsegmentation” is therefore inaccurate; microsegmentation is SGT and SGACL driven. Although overlapping IP addresses can technically exist in separate VRF-like contexts, Cisco design practice discourages unnecessary overlap because it complicates troubleshooting, service insertion, external connectivity, and inter-VN communication. A clean overlay address plan improves operations and reduces policy ambiguity. Reference topics: SD-Access overlay design, virtual networks, macro segmentation, SGTs, microsegmentation, overlapping IP avoidance. This also simplifies day-two operations.

BGP Multipath Load Sharing is the feature used when a single router has two parallel BGP paths to the same ISP and the design goal is to install more than one eligible BGP path in the routing table. By default, BGP selects a single best path after evaluating path attributes such as weight, local preference, AS path, origin, MED, eBGP over iBGP, IGP metric to next hop, and tie breakers. When the competing paths are sufficiently equivalent and BGP multipath is enabled, Cisco IOS can install multiple BGP next hops for the same prefix and allow the forwarding plane to load share across both links. Multihop is used to establish BGP sessions to non-directly connected neighbors, not to load balance. Next-Hop Address Tracking improves convergence by tracking next-hop reachability, but it does not itself create load sharing. AS-path prepending intentionally makes a path less preferred for inbound traffic engineering. Therefore, the correct BGP feature for balancing outbound traffic across two links to the same ISP is Multipath Load Sharing.

The correct design is to use the same anycast RP address on loopback interfaces so receivers and sources register with their nearest available rendezvous point. Cisco Anycast RP designs use a common RP address advertised from multiple RP routers, allowing unicast routing to direct PIM joins and registers to the closest RP. MSDP is then used between the RP routers so each RP can learn about active sources registered to the other RP. This provides resilience and local registration while keeping RP reachability consistent for the multicast domain. Option B captures the key behavior: the RP loopback is configured with the same /32 address, and normal routing sends traffic to the closest RP. Configuring a hash value, group range splitting, or equal priority alone does not provide the Anycast RP behavior required here. A professional design should also use unique loopbacks for MSDP peer sessions while keeping the shared anycast loopback as the RP address. Reference topics: Anycast RP, MSDP, PIM-SM rendezvous points, source registration, multicast high availability.