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

Interdomain multicast designs commonly use MP-BGP and MSDP together. MP-BGP carries multicast routing information between domains so routers can perform RPF checks based on the correct multicast topology rather than relying only on unicast routing. MSDP is used between rendezvous points in different PIM sparse-mode domains to exchange information about active sources. Cisco multicast documentation describes MSDP as a mechanism that connects multiple PIM-SM domains and allows RPs to discover multicast sources in other domains. Together, MP-BGP provides the reachability information and MSDP provides source discovery between RPs. IGMPv2 is a host-to-router group membership protocol inside a local subnet, not an interdomain multicast routing protocol. MLD provides the IPv6 equivalent of host group membership signaling. BIDIR-PIM is a multicast forwarding mode optimized for many-to-many traffic inside a domain, but it is not the pair of protocols used for interdomain source and receiver communication in this question. Therefore, the correct protocols are MP-BGP and MSDP.

The telemetry mapping separates dial-in and dial-out behavior. In dial-in telemetry, the collector initiates the session toward the network device and subscribes to the data that it wants streamed. This model gives the collector direct control over the subscription lifecycle, but it requires the collector to reach the device and manage each session. In dial-out telemetry, the network device initiates the session toward the collector based on a configured subscription. This is useful when devices must stream telemetry to a centralized destination through firewalls or controlled management paths. Cisco model-driven telemetry can stream structured data from YANG models using subscription behavior rather than relying on repeated CLI polling. The selected drag-and-drop answer matches each consideration to the mode that owns the connection initiation and subscription handling. In design work, the architect must consider reachability direction, security policy, NAT traversal, collector scale, subscription persistence, and whether subscriptions should be configured on the device or created by the collector. Reference topics: model-driven telemetry, dial-in mode, dial-out mode, YANG subscriptions, gRPC telemetry, operational data streaming.

The expected port state follows Rapid Spanning Tree Protocol role selection on equal-speed point-to-point links. With 802.1w, each non-root switch selects one root port based on the lowest path cost to the root bridge. Where there are redundant Layer 2 paths of equal speed, one side of a redundant segment must remain blocked as an alternate port to maintain a loop-free topology. Because all links are 1 Gbps, path cost is equal unless bridge priority, bridge ID, or port ID breaks the tie. The selected option identifies the port pair that becomes alternate blocking based on the root placement and tie-breakers shown in the exhibit. RSTP improves convergence compared with classic 802.1D by using proposal and agreement handshakes on point-to-point links, but it still blocks redundant paths when a pure Layer 2 loop exists. A design requiring all links to forward would need a routed access design, MEC, StackWise Virtual, VSS, or another loop-free multipath technology. Reference topics: RSTP, root port, designated port, alternate port, point-to-point links, Layer 2 loop prevention.