31 Days Before Your CCNA Exam

Day 12 2333. Each router builds a link-state packet (LSP) containing the state of each directly connectedlink. This is done by recording all the pertinent information about each neighbor, includingneighbor ID, link type, and bandwidth.4. Each router floods the LSP to all neighbors, who then store all LSPs received in a database.Neighbors then flood the LSPs to their neighbors until all routers in the area have received theLSPs. Each router stores a copy of each LSP received from its neighbors in a local database.5. Each router uses the database to construct a complete map of the topology and computes thebest path to each destination network. The SPF algorithm is used to construct the map of thetopology and to determine the best path to each network. All routers will have a commonmap or tree of the topology, but each router independently determines the best path to eachnetwork within that topology.OSPF ConfigurationTo review the OSPF configuration commands, we will use the topology in Figure 12-5 and theaddressing scheme in Table 12-2.Figure 12-5OSPF Configuration Topology10.10.10.0/24Lo0 10.2.2.2/32.1Fa0/0S0/0/0.2R2.9S0/0/1DCE192.168.10.0/30192.168.10.8/3064 Kbps 128 KbpsS0/0/0DCE .1.10 S0/0/1Fa0/0.5256 Kbps.6Fa0/0.17 R1S0/0/1192.168.10.4/30 S0/0/0 R3 .33172.16.1.16/28 DCE172.16.1.32/29Lo0 10.1.1.1/32 Lo0 10.3.3.3/32Table 12-2Addressing Scheme for OSPFDevice Interface IP Address Subnet MaskR1 Fa0/0 172.16.1.17 255.255.255.240S0/0/0 192.168.10.1 255.255.255.252S0/0/1 192.168.10.5 255.255.255.252Lo0 10.1.1.1 255.255.255.255continues