OSPF多区域

实验任务

1. 设备IP地址配置
2. 按照规划配置OSPF区域
3. 检查OSPF配置结果，检查OSPF邻居关系状态，在ABR上查看OSPF的LSDB
4. 在ABR、ASBR上配置路由汇总，减少区域间、外部路由数量
5. 修改OSPF的参考带宽值
6. 在OSPF中引入缺省路由

实验步骤

1、配置各个设备的接口、环回IP地址

展开代码
# AR1配置
[AR1]interface GigabitEthernet 0/0/0
[AR1-GigabitEthernet0/0/0]ip address 10.0.66.1 24
[AR1-GigabitEthernet0/0/0]q
[AR1]interface LoopBack 0
[AR1-LoopBack0]ip address 10.0.1.1 24
[AR1-LoopBack0]q

# AR2配置
[AR2]interface GigabitEthernet 0/0/0
[AR2-GigabitEthernet0/0/0]ip address 10.0.66.2 24
[AR2-GigabitEthernet0/0/0]q
[AR2]interface GigabitEthernet 0/0/1 
[AR2-GigabitEthernet0/0/1]ip address 10.0.77.2 24
[AR2-GigabitEthernet0/0/1]q
[AR2]interface LoopBack 0
[AR2-LoopBack0]ip address 10.0.2.2 24
[AR2-LoopBack0]q
[AR2]interface LoopBack 1
[AR2-LoopBack1]ip address 10.2.0.1 24
[AR2-LoopBack1]q
[AR2]interface LoopBack 2
[AR2-LoopBack2]ip address 10.2.1.1 24
[AR2-LoopBack2]q
[AR2]

# AR3配置
[AR3]interface GigabitEthernet 0/0/0
[AR3-GigabitEthernet0/0/0]ip address 10.0.66.3 24
[AR3-GigabitEthernet0/0/0]q	
[AR3]interface LoopBack 0
[AR3-LoopBack0]ip address 10.0.3.3 24
[AR3-LoopBack0]q
[AR3]interface LoopBack 1
[AR3-LoopBack1]ip address 10.3.0.1 24
[AR3-LoopBack1]q
[AR3]interface LoopBack 2
[AR3-LoopBack2]ip address 10.3.1.1 24
[AR3-LoopBack2]q

# AR4配置
[AR4]interface GigabitEthernet 0/0/0
[AR4-GigabitEthernet0/0/0]ip address 10.0.77.4 24
[AR4-GigabitEthernet0/0/0]q
[AR4]interface GigabitEthernet 0/0/1
[AR4-GigabitEthernet0/0/1]ip address 10.0.88.4 24
[AR4-GigabitEthernet0/0/1]q
[AR4]interface LoopBack 0
[AR4-LoopBack0]ip address 10.0.4.4 24
[AR4-LoopBack0]q

# AR5配置
[AR5]interface GigabitEthernet 0/0/0
[AR5-GigabitEthernet0/0/0]ip address 10.0.88.5 24 
[AR5-GigabitEthernet0/0/0]q	
[AR5]interface LoopBack 0
[AR5-LoopBack0]ip address 10.0.5.5 24
[AR5-LoopBack0]q	
[AR5]interface LoopBack 2
[AR5-LoopBack2]ip address 10.5.1.1 24
[AR5-LoopBack2]q
[AR5]interface LoopBack 1
[AR5-LoopBack1]ip address 10.5.0.1 24
[AR5-LoopBack1]q

以AR2为例，pingAR1、AR3、AR4，测试连通性

2、配置多区域OSPF

​ 在AR1、AR2、AR3、AR4、AR5设的接口中激活OSPF，同时修改环回地址接口的网络类型为Broadcast

展开代码
# AR1配置
[AR1]ospf 1 router-id 10.0.1.1
[AR1-ospf-1]area 2
[AR1-ospf-1-area-0.0.0.2]network 10.0.66.1 0.0.0.0
[AR1-ospf-1-area-0.0.0.2]network 10.0.1.1 0.0.0.0
[AR1-ospf-1-area-0.0.0.2]q
[AR1-ospf-1]q	
[AR1]interface LoopBack 0
[AR1-LoopBack0]ospf network-type broadcast 
[AR1-LoopBack0]q

# AR2配置
[AR2]ospf 1 router-id 10.0.2.2
[AR2-ospf-1]area 0
[AR2-ospf-1-area-0.0.0.0]network 10.0.77.2 0.0.0.0
[AR2-ospf-1-area-0.0.0.0]network 10.0.2.2 0.0.0.0
[AR2-ospf-1-area-0.0.0.0]q
[AR2-ospf-1]area 2
[AR2-ospf-1-area-0.0.0.2]network 10.0.66.2 0.0.0.0
[AR2-ospf-1-area-0.0.0.2]q
[AR2-ospf-1]q
[AR2]interface LoopBack 0
[AR2-LoopBack0]ospf network-type broadcast 
[AR2-LoopBack0]q

# AR3配置
[AR3]ospf 1 router-id 10.0.3.3
[AR3-ospf-1]area 2
[AR3-ospf-1-area-0.0.0.2]network 10.0.66.3 0.0.0.0
[AR3-ospf-1-area-0.0.0.2]network 10.0.3.3 0.0.0.0
[AR3-ospf-1-area-0.0.0.2]network 10.3.0.1 0.0.0.0
[AR3-ospf-1-area-0.0.0.2]network 10.3.1.1 0.0.0.0
[AR3-ospf-1-area-0.0.0.2]q
[AR3-ospf-1]q	
[AR3]interface LoopBack 0	
[AR3-LoopBack0]ospf network-type broadcast 
[AR3-LoopBack0]q
[AR3]interface LoopBack 1
[AR3-LoopBack1]ospf  network-type broadcast 
[AR3-LoopBack1]q
[AR3]interface LoopBack 2
[AR3-LoopBack2]ospf network-type broadcast 
[AR3-LoopBack2]q

# AR4配置
[AR4]ospf 1 router-id 10.0.4.4
[AR4-ospf-1]area 0
[AR4-ospf-1-area-0.0.0.0]net 	
[AR4-ospf-1-area-0.0.0.0]network 10.0.77.4 0.0.0.0
[AR4-ospf-1-area-0.0.0.0]q
[AR4-ospf-1]area 0	
[AR4-ospf-1-area-0.0.0.0]network 10.0.4.4 0.0.0.0
[AR4-ospf-1-area-0.0.0.0]q
[AR4-ospf-1]area 1
[AR4-ospf-1-area-0.0.0.1]network 10.0.88.4 0.0.0.0
[AR4-ospf-1-area-0.0.0.1]q
[AR4-ospf-1]q
[AR4]interface LoopBack 0
[AR4-LoopBack0]ospf network-type broadcast 
[AR4-LoopBack0]q

# AR5配置
[AR5]ospf 1 router-id 10.0.5.5
[AR5-ospf-1]area 1
[AR5-ospf-1-area-0.0.0.1]network 10.0.88.5 0.0.0.0
[AR5-ospf-1-area-0.0.0.1]network 10.5.0.1 0.0.0.0	
[AR5-ospf-1-area-0.0.0.1]network 10.5.1.1 0.0.0.0
[AR5-ospf-1-area-0.0.0.1]network 10.0.5.5 0.0.0.0
[AR5-ospf-1-area-0.0.0.1]q
[AR5-ospf-1]q	
[AR5]interface LoopBack 0
[AR5-LoopBack0]ospf network-type broadcast 
[AR5-LoopBack0]q
[AR5]interface  LoopBack 1
[AR5-LoopBack1]ospf network-type broadcast 
[AR5-LoopBack1]q	
[AR5]interface LoopBack 2
[AR5-LoopBack2]ospf network-type broadcast 
[AR5-LoopBack2]q

​ 基本上到了这里就配置好了OSPF的多区域

3、检查OSPF的配置结果

在AR2上检查OSPF的邻居关系的概要信息

展开代码
[AR2]display ospf peer brief

在AR5上检查邻居关系的概要信息和OSPF路由表

展开代码
[AR5]display ospf peer brief

展开代码
[AR5]display ospf routing

​ 其中三条类型为Stub的网段是AR5直连的网段，剩下的Transit的网段的Cost值为1，可以通过接口10.0.88.5到达

在AR2上查看OSPF的LSDB

展开代码
<AR2>display ospf lsdb

​ AR2作为ABR,需要维护两个区域的LSDB,分别用来描述区域0和区域2的路由

4、配置OSPF区域间、外部路由汇总

查看AR2、AR4的路由表

展开代码
[AR2]display ospf routing

​ AR2路由表上的AR5路由、AR4路由表上的AR3都可以进行区域间汇总，之后在想其他区域发送。减少路由条目和路由震荡的发生

AR4对AR5的路由进行汇总

展开代码
[AR4]ospf 1
[AR4-ospf-1]area 1
[AR4-ospf-1-area-0.0.0.1]abr-summary 10.5.0.0 255.255.254.0
[AR4-ospf-1-area-0.0.0.1]q
[AR4-ospf-1]

重新查看AR2的路由表

在AR2上对AR3进行路由汇总

展开代码
[AR2]ospf 1
[AR2-ospf-1]area 2
[AR2-ospf-1-area-0.0.0.2]abr-summary 10.3.0.0 255.255.254.0
[AR2-ospf-1-area-0.0.0.2]q
[AR2-ospf-1]

重新查看AR5的路由表

将AR2的Loopback1、2接口路由引入到OSPF中，并执行外部路由汇总

展开代码
[AR2]ospf 1
[AR2-ospf-1]import-route direct
[AR2-ospf-1]asbr-summary 10.2.0.0 255.255.254.0
[AR2-ospf-1]

5、修改OSPF的参考带宽值

​ 在运行OSPF的多个区域内，OSPF的参考带宽值必须一致，否则OSPF无法正常工作。修改所有路由器的OSPF参考带宽值为10Gps

展开代码
# AR1配置
[AR1]ospf 1
[AR1-ospf-1]bandwidth-reference 10000

# AR2配置
[AR2]ospf 1
[AR2-ospf-1]bandwidth-reference 10000

# AR3配置
[AR3]ospf 1
[AR3-ospf-1]bandwidth-reference 10000

# AR4配置
[AR4]ospf 1
[AR4-ospf-1]bandwidth-reference 10000

# AR5配置
[AR5]ospf 1
[AR5-ospf-1]bandwidth-reference 10000

查看AR2的路由表

​ 可以看到路由表中的Cost值已经发生了改变

6、OSPF引入缺省路由

展开代码
# 使用AR1的Loopback 0接口模拟Internet接入，在AR1上配置缺省路由，且出接口指定为Loopback 0
[AR1]ip route-static 0.0.0.0 0.0.0.0 LoopBack 0

# 将缺省路由引入到OSPF，指定外部路由类型为1
[AR1]ospf 1	
[AR1-ospf-1]default-route-advertise always type 1
[AR1-ospf-1]q

查看AR2的OSPF路由表

实验包

OSPF多区域https://www.alipan.com/s/8bWtTKFYH8D