Once distribution trees are built using the Protocol Independent Multicast (PIM) protocol, what occurs next?

The correct answer indicates that distribution trees created using the Protocol Independent Multicast (PIM) protocol are constantly updated. This reflects the dynamic nature of PIM, which is designed to adapt to changes in network conditions and member status.

When a multicast group member joins or leaves a group, the distribution tree is adjusted to accommodate these changes, ensuring efficient data delivery. This updating process allows the multicast traffic to remain optimized, as it can reroute through different paths to minimize latency or avoid network congestion.

This adaptability is crucial for maintaining the integrity and efficiency of multicast communications, particularly in environments where network topologies may frequently change. The PIM protocol leverages existing unicast routing protocols to facilitate these updates automatically, rather than relying on a static configuration or manual intervention. Thus, the trees evolve in response to real-time network changes, reflecting their dynamic characteristics.