How does Protocol Independent Multicast perform multicast forwarding?

PIM (Protocol Independent Multicast) is "protocol independent" because it does not build its own routing table. Instead, it leverages the existing unicast routing table to perform its Reverse Path Forwarding (RPF) checks. The RPF check is crucial for preventing loops and ensuring efficient multicast forwarding by verifying that multicast traffic arrives on the interface that would be used to send unicast traffic back to the source. This reliance on unicast routing information makes PIM flexible and adaptable to various underlying unicast routing protocols like OSPF, EIGRP, or BGP. Incorrect options: Establishing neighbor adjacencies and sending hello messages at 5-second intervals is characteristic of PIM's neighbor discovery process, not its forwarding mechanism. PIM does not use a separate "multicast routing table" for forwarding; it uses the unicast routing table for RPF. While a multicast forwarding information base (MFIB) is built, it's derived from the unicast routing table and PIM-specific control plane information. PIM does not use broadcast routing information; broadcast is a different forwarding mechanism.