Cisco Enterprise Network Core Technologies (ENCOR) Practice Exam

The broadcast address used by OSPF for non-Designated Routers (non-DR) is 224.0.0.6. In the context of OSPF, this address is specifically utilized for sending OSPF messages to all OSPF routers that are in a particular area, except for the designated router.

Within an OSPF broadcast network, routers communicate with each other through multicast addresses. The address 224.0.0.5 is utilized in OSPF for Designated Routers (DR) and handles multicast traffic designed for all OSPF routers on a broadcast multi-access network. Conversely, 224.0.0.6 is reserved for non-DR routers, ensuring that they can receive OSPF routing updates and information without overwhelming the designated router with unnecessary traffic.

Thus, recognizing the specific roles of these multicast addresses is crucial for understanding how OSPF manages routing updates and communications efficiently within a network.