How does Administrative Scoping restrict multicast traffic?

Administrative scoping restricts multicast traffic by using an Access Control List (ACL), which allows network administrators to define and control the flow of multicast traffic based on specific criteria. This involves setting rules that can allow or deny multicast packets based on factors such as source IP address, destination IP address, and port numbers. By applying these ACLs, multicast traffic can be confined to particular segments of the network or restricted entirely based on administrative policies.

This capability is crucial in managing network resources effectively and avoiding unnecessary multicast traffic on networks where it may disrupt services or bandwidth. By creating specific rules, network administrators maintain control over the multicast environment, ensuring that only intended recipients receive the multicast streams.

The other options do not accurately describe how administrative scoping functions. Increasing the Time to Live (TTL) value does not restrict traffic; rather, it can extend the reach of multicast packets. Pruning unnecessary branches of the multicast tree is part of the multicast routing protocol operation, not administrative scoping. Finally, defining a root for the multicast distribution tree pertains to the structure of multicast routing but does not equate to restricting traffic based on administrative decisions.