1. 拓扑图：
2.配置：
AR1：
interface Ethernet0/0/0
ip address 10.1.1.1 255.255.255.252 interface Serial0/0/0
link-protocol ppp
ip address 192.1.1.1 255.255.255.252 interface LoopBack0
ip address 1.1.1.1 255.255.255.255 ospf 1
area 0.0.0.0
network 10.1.1.0 0.0.0.3
network 192.1.1.0 0.0.0.3
network 1.1.1.1 0.0.0.0
AR2：
interface Ethernet0/0/0
ip address 10.1.1.2 255.255.255.252 interface Serial0/0/0
link-protocol ppp
ip address 192.2.2.2 255.255.255.252 interface LoopBack0
ip address 2.2.2.2 255.255.255.255 ospf 1
area 0.0.0.0
network 192.2.2.0 0.0.0.3
network 2.2.2.2 0.0.0.0
network 10.1.1.0 0.0.0.3
AR3：
interface Ethernet0/0/0
ip address 10.2.2.2 255.255.255.252 nterface Serial0/0/0
link-protocol ppp
ip address 192.2.2.1 255.255.255.252 interface LoopBack0
ip address 3.3.3.3 255.255.255.255 ospf 1
area 0.0.0.0
network 192.2.2.0 0.0.0.3
network 10.2.2.0 0.0.0.3
network 3.3.3.3 0.0.0.0
AR4：
interface Ethernet0/0/0
ip address 10.2.2.1 255.255.255.252 interface Serial0/0/0
link-protocol ppp
ip address 192.1.1.2 255.255.255.252 interface LoopBack0
ip address 4.4.4.4 255.255.255.255
# ospf 1
area 0.0.0.0
network 10.2.2.0 0.0.0.3
network 192.1.1.0 0.0.0.3
network 4.4.4.4 0.0.0.0
#
3.查看命令：
3.1 :display ip routing-table 查看路由表
3.2 display ip routing-table protocol ospf 查看路由表只运行OSPF
3.3 display IP routing-table protocol direct 查看路由关于直连
3.4 display ospf lsdb 查看OSPF数据库 3.5 display ospf routing 查看OSPF路由表 3.6 display ospf brief 查看OPSF总结信息 3. 7 display ospf peer 看对端的领接信息
4.收集的信息：
串口线的COST值为：1562
以太网线的COST值为：1
环回口的COST值为：1
