Explanation:
Table Description automatically generated

In PIM Sparse Mode, when the Last-Hop Router (LHR) receives multicast traffic on the shared tree (*,G), it performs an RPF check based on the RP address, not the multicast source address. In the diagram:
* The LHR has IGP cost 10 towards the RP.
* The shared tree (*,G) uses RP as the RPF target.
* Since multicast traffic on (*,G) arrives on the interface toward RP (correct RPF interface), the RPF check succeeds.
Therefore, the multicast traffic is successfully switched toward the receivers.
This behavior is fully aligned with CCDE v3.1 multicast design principles, which emphasize clear understanding of RPF behavior both on shared trees (*,G) and source trees (S,G).
Why other options are incorrect:
* A: The RPF check is not performed against the source in (*,G); it uses RP.
* B: RPF checks are always performed, even on (*,G).
* D: RPF is unrelated to the receiver address.

The question describes a network that requires virtualization at both control and data plane levels using VLANs and VRFs. This architecture aligns with:
* Path isolation (A): Achieved using VRFs and VLANs, ensuring traffic separation at Layer 2 and Layer
3 across the entire network.
* Group virtualization (C): Refers to grouping users or resources (such as departments or tenants) into isolated segments that remain logically separated throughout the campus fabric.
Other options explained:
* B (Session isolation): More aligned with application or session-layer security, not data/control plane virtualization.
* D (Services virtualization): Typically related to virtualizing network services (firewalls, load balancers).
* E (Edge isolation): Not a standard design term in CCDE.
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VPLS (Virtual Private LAN Service) is a Layer 2 VPN technology that simulates a LAN across an MPLS or IP core. VPLS uses a flood-and-learn mechanism where unknown unicast, broadcast, and multicast traffic is flooded to build the forwarding database dynamically - much like a traditional LAN switch.
* This flood-and-learn behavior leads to MAC learning based on incoming traffic, not control-plane advertisement.
* VPLS may require extra control-plane scaling mechanisms in large-scale deployments due to this learning behavior.
Other options explained:
* A (LISP): Uses mapping servers and control plane for EID-to-RLOC mapping, not flood-and-learn.
* B (OTV): Uses control-plane MAC address learning instead of data-plane flooding.
* D (EVPN): Uses BGP control-plane learning for MAC and IP address distribution.
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