多区域
ospf
一、
实验目的
学习
ospf
的基本配置，了解
ospf
的工作原理，
ABR,ASBR
的汇总，以及
DR
，
BDR
的选举。
二、
拓扑结构
三、
实验步骤
1.
准备工作
2.
基本配置
a)
基本接口的的配置
b)
测试
Singapore ping 192.168.224.1
通
sanjose ping 192.168.1.1
通
结论：线路连接没有问题
3.
配置
ospf
a) Sanjose3
Router ospf 1
network 192.168.3.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.255 area 0
network 192.168.224.1 0.0.0.3 area 51
b
）
sanjose1
router ospf 1
network 192.168.1.0 0.0.0.255 area 0
network 192.168.64.0 0.0.63.255 area 1
c
）
Singapore
router ospf 2
network 192.168.224.0 0.0.0.3 area 51
4.
测试
ospf
a) Singapore ping 192.168.3.1
通
ping 192.168.1.1
通
b) sanjose1 ping 192.168.3.1
通
ping 192.168.224.2
通
c) show ip ospf
snajose1#show ip ospf
Routing Process "ospf 1" with ID 192.168.112.1
Start time: 00:36:34.336, Time elapsed: 00:04:33.248
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an area border router
sanjose3 sanjose1
为
ABR
d
）
show ip ospf neighbor detail
sanjose3#sho ip ospf nei detail
Neighbor 192.168.112.1, interface address 192.168.1.1
In the area 0 via interface FastEthernet1/0
Neighbor priority is 1, State is FULL, 6 state changes
DR is 192.168.1.3 BDR is 192.168.1.1
Options is 0x52
LLS Options is 0x1 (LR)
Dead timer due in 00:00:31
Neighbor is up for 00:13:48
Index 1/1, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum is 0 msec
Neighbor 192.168.252.1, interface address 192.168.224.2
In the area 51 via interface Serial0/1
Neighbor priority is 0, State is FULL, 6 state changes
DR is 0.0.0.0 BDR is 0.0.0.0
Options is 0x52
LLS Options is 0x1 (LR)
Dead timer due in 00:00:36
Neighbor is up for 00:11:52
Index 1/2, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum is 0 msec
结论：区域
0
有
DR
和
BDR
因为区域
0
是广播式的以太网
区域
51
无
DR
和
BDR
因为区域
51
是点到点的网络
5. ospf
的汇总
a)
汇总原因
Singapore
的路由条目过多可进行汇总节省
cpu
的开销
192.168.224.0/30 is subnetted, 1 subnets
C 192.168.224.0 is directly connected, Serial0/1
C 192.168.240.0/24 is directly connected, Loopback1
C 192.168.244.0/24 is directly connected, Loopback2
192.168.64.0/32 is subnetted, 1 subnets
O IA 192.168.64.1 [110/66] via 192.168.224.1, 00:22:26, Serial0/1
192.168.80.0/32 is subnetted, 1 subnets
O IA 192.168.80.1 [110/66] via 192.168.224.1, 00:22:26, Serial0/1
192.168.96.0/32 is subnetted, 1 subnets
O IA 192.168.96.1 [110/66] via 192.168.224.1, 00:22:26, Serial0/1
C 192.168.248.0/24 is directly connected, Loopback3
192.168.112.0/32 is subnetted, 1 subnets
O IA 192.168.112.1 [110/66] via 192.168.224.1, 00:22:26, Serial0/1
O IA 192.168.1.0/24 [110/65] via 192.168.224.1, 00:24:13, Serial0/1
C 192.168.252.0/24 is directly connected, Loopback0
192.168.3.0/32 is subnetted, 1 subnets
O IA 192.168.3.1 [110/65] via 192.168.224.1, 00:24:13, Serial0/1
b
）汇总
snajose1(config)#router ospf 1
snajose1(config-router)#area 1 range 192.168.64.0 255.255.192.0
c
）
ASBR
的配置
singapore(config)#ip route 192.168.248.0 255.255.255.0 null0
singapore(config)#router ospf 1
singapore(config-router)#redistribute static subnets
singapore#show ip ospf
Routing Process "ospf 1" with ID 192.168.248.1
Start time: 01:21:27.320, Time elapsed: 01:09:01.136
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an autonomous system boundary router
Singapore
成为
ASBR
sanjose3#sho ip route
Gateway of last resort is not set
192.168.224.0/30 is subnetted, 1 subnets
C 192.168.224.0 is directly connected, Serial0/1
O E2 192.168.248.0/24 [110/20] via 192.168.224.2, 00:00:47, Serial0/1
C 192.168.1.0/24 is directly connected, FastEthernet1/0
C 192.168.3.0/24 is directly connected, Loopback0
O IA 192.168.64.0/18 [110/2] via 192.168.1.1, 00:00:47, FastEthernet1/0
sanjose1
O E2 192.168.248.0/24 [110/20] via 192.168.1.3, 00:04:49, FastEthernet1/0
问题：
sanjose3
与
sanjose1
到达
192.168.248.0/24
的开销值相同但实际上
sanjose3
的开销要小
解决方案：
singapore(config)#router ospf 1
singapore(config-router)#redistribute static subnets metric-type 1
6
）
ASBR
的汇总
singapore(config)#ip route 192.168.240.0 255.255.255.252 null0
singapore(config)#ip route 192.168.244.0 255.255.255.0 null0
singapore(config)#ip route 192.168.252.0 255.255.255.0 null0
singapore(config-router)#summary-address 192.168.240.0 255.255.240.0
结果
:
sanjose1
O E1 192.168.240.0/20 [110/85] via 192.168.1.3, 00:00:08, FastEthernet1/0
sanjose3
O E1 192.168.248.0/24 [110/84] via 192.168.224.2, 00:00:55, Serial0/1
6.
默认路由的配置
snajose1(config)#int lo 5
snajose1(config-if)#ip add 10.0.0.6 255.255.255.255
snajose1(config-if)#router ospf 1
snajose1(config-router)#default-information originate always
结果：
sanjose3
：
show ip route
O*E2 0.0.0.0/0 [110/1] via 192.168.1.1, 00:00:55, FastEthernet1/0
四：实验总结
学习掌握多区域
ospf
的工作原理配置，掌握
DR
、
BDR
的选举，
ABR
，
ASBR
的
概念，以及在
ABR
、
ASBR
的汇总，
ospf
的默认路由的宣告。