完成本实验，您应该能够：
掌握单区域OSPF配置方法
掌握OSPF路由选择的方法
步骤一：搭建实验环境
步骤二：基本配置
[rta]int GigabitEthernet 0/0
[rta-GigabitEthernet0/0]ip add 20.0.0.1 24
[rta-GigabitEthernet0/0]int g0/1
[rta-GigabitEthernet0/1]ip add 10.0.0.2 24
[rta-GigabitEthernet0/1]int loopback 0
[rta-LoopBack0]ip add 1.1.1.1 32
[rtb]int GigabitEthernet 0/0
[rtb-GigabitEthernet0/0]ip add 20.0.0.2 24
[rtb-GigabitEthernet0/0]int g0/1
[rtb-GigabitEthernet0/1]ip add 10.1.0.2 24
[rtb-GigabitEthernet0/1]int loopback 0
[rtb-LoopBack0]ip add 2.2.2.2 32
步骤三：检查网络连通性和路由器路由表
在clienta上ping clientb，显示如下：
C:Documents and SettingsAdministrator>ping 10.1.0.1
Pinging 10.1.0.1 with 32 bytes of data:
Reply from 10.0.0.2: Destination net unreachable.
Reply from 10.0.0.2: Destination net unreachable.
Reply from 10.0.0.2: Destination net unreachable.
Reply from 10.0.0.2: Destination net unreachable.
Ping statistics for 10.1.0.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms
结果显示，无法ping通。这是因为在rta上没有到10.1.0.1的路由。
在rta上使用dis ip routing-table命令查看路由表，显示如下：
[rta]dis ip routing-table
Routing Tables: Public
Destinations : 7 Routes : 7
Destination/Mask Proto Pre Cost NextHop Interface
1.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0
10.0.0.0/24 Direct 0 0 10.0.0.2 GE0/1
10.0.0.2/32 Direct 0 0 127.0.0.1 InLoop0
20.0.0.0/24 Direct 0 0 20.0.0.1 GE0/0
20.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
Rta上只有直连路由，没有到达clientb的路由表项。
步骤四：配置OSPF
[rta]router id 1.1.1.1
[rta]ospf 1
[rta-ospf-1]area 0.0.0.0
[rta-ospf-1-area-0.0.0.0]network 1.1.1.1 0.0.0.0
[rta-ospf-1-area-0.0.0.0]network 10.0.0.0 0.0.0.255
[rta-ospf-1-area-0.0.0.0]network 20.0.0.0 0.0.0.255
[rtb]router id 2.2.2.2
[rtb]ospf 1
[rtb-ospf-1]area 0
[rtb-ospf-1-area-0.0.0.0]network 2.2.2.2 0.0.0.0
[rtb-ospf-1-area-0.0.0.0]network 10.1.0.0 0.0.0.255
[rtb-ospf-1-area-0.0.0.0]network 20.0.0.0 0.0.0.255
步骤五：检查路由器OSPF邻居状态及路由表
在rta上使用display ospf peer命令查看OSPF邻居状态，显示如下：
[rta]display ospf peer
OSPF Process 1 with Router ID 1.1.1.1
Neighbor Brief Information
Area: 0.0.0.0
Router ID dress Pri Dead-Time Interface State
2.2.2.2 20.0.0.2 1 30 GE0/0 Full/BDR
Rta与router id为2.2.2.2的路由器上配置IP地址20.0.0.2的接口互为邻居，rtb的配置IP地址20.0.0.2的接口为该网段的DR路由器。此时，邻居状态达到full，说明rta和rtb之间的链路状态数据库已经同步，rta具备到达rtb的路由信息。
在rta上使用display ospf routing命令查看路由器的OSPF的OSPF路由表，显示如下：
[rta]display ospf routing
OSPF Process 1 with Router ID 1.1.1.1
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
20.0.0.0/24 1 Transit 20.0.0.1 1.1.1.1 0.0.0.0
10.0.0.0/24 1 Stub 10.0.0.2 1.1.1.1 0.0.0.0
2.2.2.2/32 1 Stub 20.0.0.2 2.2.2.2 0.0.0.0
10.1.0.0/24 2 Stub 20.0.0.2 2.2.2.2 0.0.0.0
1.1.1.1/32 0 Stub 1.1.1.1 1.1.1.1 0.0.0.0
Total Nets: 5
Intra Area: 5 Inter Area: 0 ASE: 0 NSSA: 0
在rta上使用命令查看路由器全局路由表，显示如下：
[rta]display ip routing-table
Routing Tables: Public
Destinations : 9 Routes : 9
Destination/Mask Proto Pre Cost NextHop Interface
1.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0
2.2.2.2/32 OSPF 10 1 20.0.0.2 GE0/0
10.0.0.0/24 Direct 0 0 10.0.0.2 GE0/1
10.0.0.2/32 Direct 0 0 127.0.0.1 InLoop0
10.1.0.0/24 OSPF 10 2 20.0.0.2 GE0/0
20.0.0.0/24 Direct 0 0 20.0.0.1 GE0/0
20.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
此时，全网络是连通的。
