his interface, we'd use the following net work command: Router-A(config-router)#network 10.10.10.0 0.0.0.255 After executing this command, the running configuration will still contain the less spe- cific 10.0.0.0 network statement: router eigrp 100 network 10.10.10.0 0.0.0.255 network 10.0.0.0 Both commands will take effect. Be careful of this, as it can cause no end of frustration. In this example, it will cause the interface E1/1 to be included in EIGRP 100, which is not what we want. We need to remove the less specific network command by negating it: router eigrp 100 no network 10.0.0.0 It's a very good practice to enable only the specific interface you wish to add in any routing process that supports it. You can do this by specifying the IP address on the interface with an all-zeros mask. In our example, the command is network 10.10.10.1 0.0.0.0. This prevents surprises should network masks change or interfaces be renum- bered. Thus, my preferred configuration for EIGRP on the router shown in Fig- ure 10-11 is: router eigrp 100 network 10.10.10.1 0.0.0.0 network 192.168.1.1 0.0.0.0 router eigrp 200 network 10.20.20.1 0.0.0.0 network 192.168.2.1 0.0.0.0 EIGRP summarizes routes the same way RIP does, but because EIGRP is a classless protocol, we can disable this behavior with the no auto-summary command: Router-A(config-router) #no auto-summary Specific Routing Protocols There are very few instances where you'd want to leave autosummary on, SO you should get into the habit of disabling it. EIGRP operates by sending out hello packets using the multicast IP address 224.0.0.10 on configured interfaces. When a router running EIGRP receives these hello packets, it checks to see if the hello contains a process number matching an EIGRP process running locally. If it does, a handshake is performed. If the handshake is successful, the routers become neighbors. Unlike RIP, which broadcasts routes to anyone who'll listen, EIGRP routers exchange routes only with neighbors. Once a neighbor adjacency has been formed, update 