What is the multicast address EIGRP devices use to exchange messages?

EIGRP (Enhanced Interior Gateway Routing Protocol) uses the multicast address 224.0.0.10 for exchanging messages. This address is specifically designated for routing protocol communications. When EIGRP routers need to share updates, link status, and other important information, they send packets to this multicast address. Using a multicast address allows a single message to be sent to multiple EIGRP-enabled routers simultaneously, optimizing bandwidth and reducing unnecessary traffic compared to unicast communication.

In the context of EIGRP, this multicast address is essential for the protocol's operation because it efficiently disseminates routing information to all routers within the same EIGRP routing domain. Each device that is an EIGRP neighbor listens to this specific multicast address to receive updates, which helps maintain a consistent view of the network topology.