0.0.0.0 Specific Routing Protocols 192.192.192.0/30 is subnetted, 1 subnets 192.192.192.4 is directly connected, Serial0/o 172.16.0.0/32 is subnetted, 1 subnets 172.16.1.1 [110/11] via 10.10.10.4, 00:00:09, Etherneto/o 10.0.0.0/24 is subnetted, 1 subnets 10.10.10.0 is directly connected, Etherneto/o 192.168.1.0/24 is directly connected, Ethernet1/0 0.0.0.0/0 [254/0] via 192.168.1.2 Various OSPF route types are described in the routing table. They are: 0 (OSPF), 0 IA (OSPF inter-area), 0 N1 (OSPF NSSA external type 1), and 0 N2 (OSPF NSSA external type 2). OSPF stores its routes in a database, much like EIGRP. The command to show the database is show ip ospf database: R3# sho ip ospf database OSPF Router with ID (192.192.192.5) (Process ID 100) Router Link States (Area 0) Link ID ADV Router Checksum Link count 192.192.192.5 192.192.192.5 0x8000002A 0x00C190 1 Summary Net Link States (Area 0) Link ID ADV Router Checksum 192.192.192.4 192.192.192.5 0x8000002A 0x003415 Router Link States (Area 1) Link ID ADV Router Checksum Link count 192.192.192.5 192.192.192.5 0x8000002A 0x00B046 1 Summary Net Link States (Area 1) Link ID ADV Router Checksum 10.10.10.0 192.192.192.5 0x8000002A 0x0002A2 OSPF Router with ID (192.168.1.116) (Process ID 1) If all of this seems needlessly complicated to you, you're not alone. The complexity of OSPF is one of the reasons that many people choose EIGRP instead. If you're working in a multivendor environment, however, EIGRP is not an option. The Border Gateway Protocol (BGP) is a very different protocol from the others described here. The most obvious difference is that BGP is an external gateway pro- tocol, while all the previously discussed protocols were internal gateway protocols. Chapter 10: Routing Protocols BGP can be hard to understand for those who have only ever dealt with internal protocols like EIGRP and OSPF because the very nature of the protocol is different. As BGP is not often seen in the corporate environment, I'll only cover it briefly here. BGP does not deal with hops or