实验拓扑图如下所示
操作步骤：
步骤1：连接网络拓扑图。
步骤2：设置计算机的IP地址、子网掩码和网关。
步骤3：配置Router-A的名称及其接口IP地址。
Router_config#hostname Router-A
Router-A_config#int fa0/0
Router-A_config_f0/0#ip add 192.168.3.1 255.255.255.0
Router-A_config_f0/0#no shutdown
Router-A_config_f0/0#interface serial 0/1
Router-A_config_s0/1# physical-layer speed 64000
Router-A_config_s0/1#ip address 192.168.4.1 255.255.255.0
Router-A_config_s0/1#no shutdown
Router-A_config_s0/1#int Ga0/3
Router-A_config_G0/3#ip add 192.168.5.1 255.255.255.0
Router-A_config_G0/3#no shutdown
步骤4：配置Router-B的名称及其接口IP地址。
Router_config#hostname Router-B
Router-B_config#int fa0/0
Router-B_config_f0/0#ip add 192.168.1.1 255.255.255.0
Router-B_config_f0/0#no shutdown
Router-B_config_f0/0#interface serial 0/2
Router-B_config_s0/2#ip address 192.168.4.2 255.255.255.0
Router-B_config_s0/1#no shutdown
步骤5：配置Router-C的名称及其接口IP地址。
Router_config#hostname Router-C
Router-C_config#int fa0/0
Router-C_config_f0/0#ip add 192.168.2.1 255.255.255.0
Router-C_config_f0/0#no shutdown
Router-C_config_f0/0#int Ga0/3
Router-C_config_G0/3#ip add 192.168.5.2 255.255.255.0
Router-C_config_G0/3#no shutdown
步骤6：查看Router-A的路由表。
Router-A#show ip route
VRF ID: 0
C 192.168.3.0/24 is directly connected, FastEthernet0/0
C 192.168.4.0/24 is directly connected, Serial0/1
C 192.168.5.0/24 is directly connected, GastEthernet0/3
步骤7：查看Router-B的路由表。
Router-B#show ip route
VRF ID: 0
C 192.168.1.0/24 is directly connected, FastEthernet0/0
C 192.168.4.0/24 is directly connected, Serial0/2
步骤8：查看Router-C的路由表。
Router-C#show ip route
VRF ID: 0
C 192.168.2.0/24 is directly connected, FastEthernet0/0
C 192.168.5.0/24 is directly connected, GastEthernet0/3
步骤9：配置路由协议前，验证网络的连通性。
- （1）在PC1上ping 192.168.2.2和192.168.3.2，网络不通
- （2）在PC2上ping 192.168.1.2和192.168.3.2，网络不通
- （3）在PC3上ping 192.168.1.2和192.168.2.2，网络不通
步骤10：在Router-A上配置OSPF的多区域。
Router-A_config#router ospf 1
Router-A_config_ospf_1#network 192.168.3.0 255.255.255.0 area 0
Router-A_config_ospf_1#network 192.168.4.0 255.255.255.0 area 0
Router-A_config_ospf_1#network 192.168.5.0 255.255.255.0 area 0
步骤11：在Router-B上配置OSPF的多区域。
Router-B_config#router ospf 1
Router-B_config_ospf_1#network 192.168.1.0 255.255.255.0 area 1
Router-B_config_ospf_1#network 192.168.4.0 255.255.255.0 area 0
步骤12：在Router-C上配置OSPF。
Router-C_config#router ospf 1
Router-C_config_ospf_1#network 192.168.2.0 255.255.255.0 area 2
Router-C_config_ospf_1#network 192.168.5.0 255.255.255.0 area 0
步骤13：查看Router-A的路由表。
Router-A#show ip route
O IA 192.168.1.0/24 [110,1601] via 192.168.4.2(on Serial0/1)
O IA 192.168.2.0/24 [110,2] via 192.168.5.2(on GastEthernet0/3)
C 192.168.3.0/24 is directly connected, FastEthernet0/0
C 192.168.4.0/24 is directly connected, Serial0/1
C 192.168.5.0/24 is directly connected, GastEthernet0/3
步骤14：查看Router-B的路由表。
Router-B#show ip route
C 192.168.1.0/24 is directly connected, FastEthernet0/0
O IA 192.168.2.0/24 [110,1602] via 192.168.4.1(on Serial0/2)
O 192.168.3.0/24 [110,1601] via 192.168.4.1(on Serial0/2)
C 192.168.4.0/24 is directly connected, Serial0/2
O 192.168.5.0/24 [110,1601] via 192.168.4.1(on Serial0/2)
步骤15：查看Router-C的路由表。
Router-C#show ip route
O IA 192.168.1.0/24 [110,1602] via 192.168.5.1(on GastEthernet0/3)
C 192.168.2.0/24 is directly connected, GastEthernet0/0
O 192.168.3.0/24 [110,2] via 192.168.5.1(on GastEthernet0/3)
O 192.168.4.0/24 [110,1601] via 192.168.5.1(on GastEthernet0/3)
C 192.168.5.0/24 is directly connected, GastEthernet0/3
步骤16：配置路由协议后，验证网络的连通性。
- （1）在PC1上ping 192.168.2.2和192.168.3.2，网络已通
- （2）在PC2上ping 192.168.1.2和192.168.3.2，网络已通
- 在PC3上ping 192.168.1.2和192.168.2.2，网络已通
