OSPF route protocol interface Startup Process

Test principle of the OSPF router interface Startup Process: The OPSF interface is in the DOWN state and does not exchange information with any neighbors. INIT status: Send the HELLO packet (type 1) TWO-WAY bidirectional status every 10 seconds: basic status. When you see the HELLO packet that appears on the neighbor router, it enters the bidirectional state. www.2cto.com EXSTART: two neighboring routers use DBD data packets to negotiate the master-slave relationship. Routers with the highest OSPF router ID win the master (debug ip ospf events ). EXCHANGE switching status: vrouters describe each other's link status databases. LOADING status: receiving Type 3 (LSR Status Request package)-response type 4 (LSU link status update package)-validation type 5 (LSA link status confirmation package)
Full adjacency full joining status: generate the adjacent database (list of neighboring routers), and generate the link status database (topology database) and forwarding database (route table. DR/BDR election is only conducted in broadcast-type multi-channel access networks. Most of them are Ethernet environments. Test topology: www.2cto.com

Actual environment: only the fa0/0 interface is configured:

On R1: configure the interface address: 1 (config) # int fa0/01 (config-if) # ip add 192.168.1.1 255.255.255.01 (config-if) # no shut startup protocol: 1 (config) # router ospf 11 (config-router) # net 192.168.1.0 0.0.0.255 area 01 (config-router) # end on R2: configuration interface: 2 (config) # int fa0/02 (config-if) # ip add 192.168.1.2 route 00000000000002 (config-if) # no shut startup Protocol: 2 (config) # router ospf 12 (config-router) # net 192.168.1.0 0.0.0.255 area 0 www.2cto.com on R3: configuration interface: 3 (config) # in T fa0/03 (config-if) # ip add 192.168.1.3 255.255.255.0 startup Protocol: 3 (config) # router ospf 13 (config-router) # net 192.168.1.0 0.0.255 area 0 start testing: directly observe the neighbor's status and you can see the entire process: On R1: 1 # show ip ospf neiNeighbor ID Pri State Dead Time Address Interface192.168.1.2 1 INIT/DROTHER 00:00:31 192.168.1.2 FastEthernet0/0192.168.1.3 1 INIT/DROTHER 00:00:34 192.168.1.3 FastEthernet0/0 initialization status, 10/second, send hello. 1 # show ip ospf nei enters the bidirectional status: neighbor ID Pri State Dead Time Address Interface192.168.1.2 1 2WAY/DROTHER 00:00:29 192.168.1.2 FastEthernet0/0192.168.1.3 1 2WAY/DROTHER 00:00:33 192.168.1.3 FastEthernet0/01 # show ip ospf neiNeighbor ID Pri State Dead Time Address Interface192.168.1.2 2 /DROTHER 00:00:30 192.168.1.2 FastEthernet0/0192.168.1.3 1 EXSTART/DR 00:00:33 192.168.1.3 FastEthernet0/0 www.2cto. Com R3 starts the quasi-startup status and starts DR/BR election. 1 # show ip ospf nei election is complete, loading is complete, full connection is formed, and route table is implemented. Neighbor ID Pri State Dead Time Address Interface192.168.1.2 1 EXSTART/BDR 00:00:39 192.168.1.2 FastEthernet0/0192.168.1.3 1 FULL/DR 00:00:39 192.168.1.3 FastEthernet0/0
The other two routes can also see the election process. Debug ip ospf: Check the neighbors and observe the election of DR/BDR dynamically.