CCNA Practice Exam 2026 – Complete Study Resource

The multicast address for all-router multicast access is specifically FF02::4. This address is designated for routing protocols that need to communicate with all routers on the local link. It enables routers that are running multicast routing protocols to join and listen for updates or information from other routers using the same address.

While other addresses are multicast addresses as well, each serves a different purpose. For example, FF02::1 is for all-nodes, FF02::2 is for all-routers in specific contexts, and FF02::3 usually corresponds to a group of specific applications or protocols. The choice of FF02::4 is critical for ensuring proper communication among routers in a multicast environment, particularly for protocols like OSPF or PIM which rely on this communication to function correctly in distributed network architectures.