一、配置IP地址

1.1.数网络域

除R4环回地址外，加上环回地址一共5个网段

1.2划分IP

如图配置IP

1.3配置IP

AR1：

[AR1]interface g0/0/0 [AR1-GigabitEthernet0/0/0]ip add [AR1-GigabitEthernet0/0/0]ip address 192.168.1.1 29 [AR1-GigabitEthernet0/0/0] Nov 2 2026 09:47:42-08:00 AR1 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP on the interface GigabitEthernet0/0/0 has entered the UP state. [AR1-GigabitEthernet0/0/0]q [AR1]int [AR1]interface Lo [AR1]interface LoopBack 0 [AR1-LoopBack0]ip add [AR1-LoopBack0]ip address 192.168.1.65 30

AR2：

[AR2]interface g0/0/0 [AR2-GigabitEthernet0/0/0]ip add [AR2-GigabitEthernet0/0/0]ip address 192.168.1.2 29 Nov 2 2026 09:48:53-08:00 AR2 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP on the interface GigabitEthernet0/0/0 has entered the UP state. [AR2-GigabitEthernet0/0/0]q [AR2]int [AR2]interface Loo [AR2]interface LoopBack 0 [AR2-LoopBack0]ip add [AR2-LoopBack0]ip address 192.168.1.73 30

AR3：

[AR3]interface g0/0/0 [AR3-GigabitEthernet0/0/0]ip add [AR3-GigabitEthernet0/0/0]ip address 192.168.1.3 29 Nov 2 2026 09:55:03-08:00 AR3 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP on the interface GigabitEthernet0/0/0 has entered the UP state. [AR3-GigabitEthernet0/0/0]q [AR3]interface g0/0/1 [AR3-GigabitEthernet0/0/1]ip add [AR3-GigabitEthernet0/0/1]ip address 192.168.1.33 30 Nov 2 2026 09:57:59-08:00 AR3 %%01IFNET/4/LINK_STATE(l)[1]:The line protocol IP on the interface GigabitEthernet0/0/1 has entered the UP state. [AR3]int [AR3]interface Loo [AR3]interface LoopBack 0 [AR3-LoopBack0]ip add [AR3-LoopBack0]ip address 192.168.1.81 30

AR4：

[AR4]interface g0/0/0 [AR4-GigabitEthernet0/0/0]ip add [AR4-GigabitEthernet0/0/0]ip address 192.168.1.34 30 Nov 2 2026 09:56:23-08:00 AR4 %%01IFNET/4/LINK_STATE(l)[0]:The line protocol IP on the interface GigabitEthernet0/0/0 has entered the UP state. [AR4]interface LoopBack 0 [AR4-LoopBack0]ip add [AR4-LoopBack0]ip address 4.4.4.4 24

二、配置OSPF

AR1：

[AR1]ospf 1 router-id 192.168.1.65 [AR1-ospf-1]area 0 [AR1-ospf-1-area-0.0.0.0]net [AR1-ospf-1-area-0.0.0.0]network 192.168.1.65 0.0.0.0 [AR1-ospf-1-area-0.0.0.0]network 192.168.1.1 0.0.0.0

AR2：

[AR2]ospf 1 router-id 192.168.1.73 [AR2-ospf-1]ar [AR2-ospf-1]area 0 [AR2-ospf-1-area-0.0.0.0]network 192.168.1.73 0.0.0.0 [AR2-ospf-1-area-0.0.0.0]net [AR2-ospf-1-area-0.0.0.0]network 192.168.1.2 0.0.0.0

AR3：

[AR3]ospf 1 router-id 192.168.1.81、 [AR3-ospf-1]area 0 [AR3-ospf-1-area-0.0.0.0]network 192.168.1.81 0.0.0.0 [AR3-ospf-1-area-0.0.0.0]network 192.168.1.3 0.0.0.0 [AR3-ospf-1]area 1 [AR3-ospf-1-area-0.0.0.1]network 192.168.1.33 0.0.0.0

AR4：

[AR4]ospf 1 router-id 4.4.4.4 [AR4-ospf-1]ar [AR4-ospf-1]area 1 [AR4-ospf-1-area-0.0.0.1]net [AR4-ospf-1-area-0.0.0.1]network 192.168.1.34 0.0.0.0

测试AR4ping AR1

[AR4]ping 192.168.1.65 PING 192.168.1.65: 56 data bytes, press CTRL_C to break Reply from 192.168.1.65: bytes=56 Sequence=1 ttl=254 time=50 ms Reply from 192.168.1.65: bytes=56 Sequence=2 ttl=254 time=60 ms Reply from 192.168.1.65: bytes=56 Sequence=3 ttl=254 time=50 ms Reply from 192.168.1.65: bytes=56 Sequence=4 ttl=254 time=50 ms Reply from 192.168.1.65: bytes=56 Sequence=5 ttl=254 time=30 ms --- 192.168.1.65 ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 30/48/60 ms

三、R3为DR设备

3.1修改AR1和AR2的优先级

[AR1-GigabitEthernet0/0/0]ospf dr-priority 0 [AR2-GigabitEthernet0/0/0]ospf dr-priority 0

3.2重新加载ospf

<AR3>reset ospf 1 process

3.3检验是否为DR设备

<AR3>display ospf interface g0/0/0 OSPF Process 1 with Router ID 192.168.1.81 Interfaces Interface: 192.168.1.3 (GigabitEthernet0/0/0) Cost: 1 State: DR Type: Broadcast MTU: 1500 Priority: 1 Designated Router: 192.168.1.3 Backup Designated Router: 0.0.0.0 Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

四、配置接口认证

#AR1 [AR1]interface g0/0/0 [AR1-GigabitEthernet0/0/0]ospf authentication-mode simple plain 123456 #AR2 [AR2]interface g0/0/0 [AR2-GigabitEthernet0/0/0]ospf authentication-mode simple plain 123456 #AR3 [AR3]interface g0/0/0 [AR3-GigabitEthernet0/0/0]ospf authentication-mode simple plain 123456 [AR3]interface g0/0/1 [AR3-GigabitEthernet0/0/1]ospf authentication-mode simple plain 123456 #AR4 [AR4]interface g0/0/0 [AR4-GigabitEthernet0/0/0]ospf authentication-mode simple plain 123456

五、区域汇总

[AR3]ospf 1 [AR3-ospf-1]ae [AR3-ospf-1]ar [AR3-ospf-1]are [AR3-ospf-1]area 0 [AR3-ospf-1-area-0.0.0.0]abr-summary 192.168.1.0 255.255.255.240

六、防止路由环路

#配置缺省源 [AR4-ospf-1]default-route-advertise always