CCNP Routing Study Guide- P12:T his book is intended to help you continue on your exciting new path toward obtaining your CCNP and CCIE certification. Before reading this book, it is important to have at least read the Sybex CCNA: Cisco Certified Network Associate Study Guide, Second Edition. You can take the CCNP tests in any order, but you should have passed the CCNA exam before pursuing your CCNP. | 294 Chapter 8 Configuring Basic BGP the source router. An eBGP peer will have a different ASN than the source router. Now let s look at an example based on Figure . We ll add RouterB which is at and identify the network in which to advertise to our neighbor RouterB config-router neighbor remote-as 63001 The loopback IP address can be used for both iBGP and eBGP peers. Additional commands must be used when creating a peering session with a loopback interface. For iBGP sessions the only additional command is the update-source command. The available syntaxes are as follows neighbor address peer-group-name update-source interface-type interface-number The IP address of the loopback should be used for the peer address. Since the loopback interface is being used as the source of the BGP session the interface-type should be entered as the loopback. The interfacenumber is the number of the loopback interface that is being used for BGP peering. This is configured on the router using the loopback address. The following command adds networks and creates a route in the BGP table if the route is present in the IP table network network-number Let s look at an example adding our own network RouterA config-router network backdoor Specify a BGP backdoor route mask Network mask route-map Route-map to modify the attributes weight Set BGP weight for network cr RouterA config-router network mask backdoor Specify a BGP backdoor route route-map Route-map to modify the attributes weight Set BGP weight for network cr RouterA config-router network mask RouterA config-router Copyright 2001 SYBEX Inc. Alameda CA Minimal Configuration 295 Again network-number represents the network that is to be advertised using the BGP process. The IP network specified in the BGP network statement does not have to be directly connected to the router. Network statements within the BGP protocol session allow
