oints to 192.168.1.1 and has a metric of 1. The second default route points to 10.0.0.1 and has a metric of 2. Routes with the best metrics are inserted into the routing table, SO in this case, the first route will win. Should the network 192.168.1.0 become unavailable, all routes pointing to it will be removed from the routing table. At this time, the default route to 10.0.0.1 will be inserted into the routing table, since it now has the best metric for the 0.0.0.0/0 network. The floating static route allows routes to change if a directly connected interface goes down, but it cannot protect routes from failing if a remote device or link fails. Dy- namic routing protocols usually allow all routers participating in the protocol to learn about any failures on the network through regular communication between routers. Communication Between Routers Routers need to communicate with one another to learn the state of the network. One of the original routing protocols, the RIP, sent out updates about the network using broadcasts. This was fine for smaller networks, but as networks grew, these broadcasts became troublesome. Every host on a network listens to broadcasts, and with RIP, the broadcasts can be quite large. Most modern routing protocols communicate on broadcast networks using multicast packets. Multicast packets have specific IP and corresponding MAC addresses that reference predetermined groups of devices. Because routing is usually a dynamic process, existing routers must be able to discover new routers to add their information into the tables that describe the network. For example, all EIGRP (Enhanced Internal Gateway Routing Protocol) routers within the same domain must be able to communicate with each other. Defining specific neigh- bors is not necessary with this protocol, because they are discovered dynamically. Most interior gateway protocols discover neighbors dynamically. BGP (Border Gateway Protocol) does not discover neighbors. Instead, BGP must be configured to communicate with each neighbor manual