ＯＳＰＦｃｏｓｔ修改需求：让R1到达3.3.3.0网络优选R2到达配置：R1interfaceLoopback0ipaddress1.1.1.1255.255.255.0interfaceFastEthernet0/0ipaddress13.1.1.1255.255.255.0ipospfnetworkbroadcastduplexhalf!interfaceSerial1/0ipaddress12.1.1.1255.255.255.0ipospfnetworkbroadcastserialrestart-delay0routerospf1router-id1.1.1.1log-adjacency-changesnetwork1.1.1.10.0.0.0area0network12.1.1.10.0.0.0area0network13.1.1.10.0.0.0arealinecon0exec-timeout00passwordconsoleloggingsynchronousloginlineaux0linevty04R2interfaceLoopback0ipaddress2.2.2.2255.255.255.0interfaceFastEthernet0/0noipaddressshutdownduplexhalf!interfaceSerial1/0ipaddress12.1.1.2255.255.255.0serialrestart-delay0!interfaceSerial1/1ipaddress23.1.1.1255.255.255.0serialrestart-delay0routerospf1router-id2.2.2.2log-adjacency-changesnetwork2.2.2.20.0.0.0area0network12.1.1.10.0.0.0area0network12.1.1.20.0.0.0area0network23.1.1.10.0.0.0area0R3interfaceLoopback0ipaddress3.3.3.3255.255.255.0!interfaceFastEthernet0/0ipaddress13.1.1.2255.255.255.0duplexhalf!interfaceSerial1/0ipaddress23.1.1.2255.255.255.0serialrestart-delay0routerospf1router-id3.3.3.3log-adjacency-changesnetwork3.3.3.30.0.0.0area0network13.1.1.10.0.0.0area0network13.1.1.20.0.0.0area0network23.1.1.20.0.0.0area0验证配置;R1#showiprouteGatewayoflastresortisnotset1.0.0.0/24issubnetted,1subnetsC1.1.1.0isdirectlyconnected,Loopback02.0.0.0/32issubnetted,1subnetsO2.2.2.2[110/65]via12.1.1.2,00:36:26,Serial1/03.0.0.0/32issubnetted,1subnetsO3.3.3.3[110/2]via13.1.1.2,00:36:26,FastEthernet0/023.0.0.0/24issubnetted,1subnetsO23.1.1.0[110/65]via13.1.1.2,00:36:26,FastEthernet0/012.0.0.0/24issubnetted,1subnetsC12.1.1.0isdirectlyconnected,Serial1/013.0.0.0/24issubnetted,1subnetsC13.1.1.0isdirectlyconnected,FastEthernet0/0R1选择以太网接口直接到达R3的3.3.3.0网络，因为这条路径的COST(度量值)最低，如果选择R2到达R3,COST是129（64+64+1）那为什么以太网接口的连得路径度量值是2。是这样的吗（1+1），环回接口的链路度量值是1修改R1和R2接口的OSPF度量值R1(config)#ints1/0R1(config-if)#ipospfcost1R2(config)#ints1/1R2(config-if)#ipospfcost1再次查看R1路由表R1#showiprouteGatewayoflastresortisnotset1.0.0.0