Which multicast address is used for all EIGRP routers?

The multicast address used for all EIGRP (Enhanced Interior Gateway Routing Protocol) routers is 224.0.0.10. This address is specifically designated for EIGRP updates and allows all EIGRP routers within a network to receive routing updates sent by any EIGRP-capable router.

Using this multicast address is efficient because it eliminates the need for individual unicast messages to each router, reducing overhead and improving the speed of updates. Routers listening for EIGRP messages will monitor the 224.0.0.10 address to automatically participate in the EIGRP routing process, ensuring they receive the necessary information to maintain an accurate routing table.

Other addresses mentioned do not serve this particular function within EIGRP. For instance, 224.0.0.0 is a reserved address for the "all hosts" multicast, while 224.0.0.2 is meant for OSPF routers and 224.0.0.5 is used for RIP (Routing Information Protocol). Each multicast address is designated for specific protocols, which aids devices in filtering out the relevant traffic they need to process.