cisco怎么配置OSPF虚链路
cisco公司已成为公认的全球网络互联解决方案的领先厂商，该公司出产的一系列路由器更是引领全球，那么你知道cisco怎么配置OSPF虚链路吗?下面是小编整理的一些关于cisco怎么配置OSPF虚链路的相关资料，供你参考。
cisco配置OSPF虚链路的方法
这个配置将验证一个OSPF虚电路(Virtual-Link)的过程，重点在观察虚链路连接的临时网络与正常区域间路由有何区别。上图中区域4(area 4)没有和area 0直接相连。在R2与R3之间配置了一条虚链路。
// R1 //
int lo0
ip ad 1.1.1.1 255.255.255.0
int e0
ip ad 192.1.1.1 255.255.255.0
router os 1
network 192.1.1.0 0.0.0.255 area 0
// R2 //
int lo0
ip ad 2.2.2.2 255.255.255.0
int e0
ip ad 192.1.1.2 255.255.255.0
int e1
ip ad 193.1.1.2 255.255.255.0
router os 1
network 192.1.1.0 0.0.0.255 area 0
network 193.1.1.0 0.0.0.255 area 1
// R3 //
int lo0
ip ad 3.3.3.3 255.255.255.0
int e1
ip ad 193.1.1.3 255.255.255.0
int e0
ip ad 194.1.1.3 255.255.255.0
router os 1
network 193.1.1.0 0.0.0.255 area 1
network 194.1.1.0 0.0.0.255 area 4
// R4 //
int lo0
ip ad 4.4.4.4 255.255.255.0
int e0
ip ad 194.1.1.4 255.255.255.0
router os 1
network 194.1.1.0 0.0.0.255 area 4
基本配置完成后，我们在每台路由器上分别来验证一下：
r1#sh ip os nei
Neighbor ID Pri State Dead Time Address Interface
2.2.2.2 1 FULL/BDR 00:00:33 192.1.1.2 Ethernet0/0
r1#
r1#sh ip ro
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
O IA 193.1.1.0/24 [110/20] via 192.1.1.2, 00:00:19, Ethernet0/0
C 192.1.1.0/24 is directly connected, Ethernet0/0
//注意R1上有关于193.1.1.0的路由条目，是属于IA类型(域间路由)
r2#sh ip os nei
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/DR 00:00:35 192.1.1.1 Ethernet0/0
3.3.3.3 1 FULL/BDR 00:00:35 193.1.1.3 Ethernet1/0
r2#
r2#
r2#sh ip ro
2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
C 193.1.1.0/24 is directly connected, Ethernet1/0
C 192.1.1.0/24 is directly connected, Ethernet0/0
r3#sh ip os nei
Neighbor ID Pri State Dead Time Address Interface
2.2.2.2 1 FULL/DR 00:00:32 193.1.1.2 Ethernet1/0
4.4.4.4 1 FULL/DR 00:00:34 194.1.1.4 Ethernet0/0
r3#sh ip ro
3.0.0.0/24 is subnetted, 1 subnets
C 3.3.3.0 is directly connected, Loopback0
C 193.1.1.0/24 is directly connected, Ethernet1/0
O IA 192.1.1.0/24 [110/20] via 193.1.1.2, 00:02:49, Ethernet1/0
C 194.1.1.0/24 is directly connected, Ethernet0/0
//注意R3中有关于192.1.1.0的路由是属于IA类型(域间路由)
r4#sh ip os nei
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 1 FULL/BDR 00:00:33 194.1.1.3 Ethernet0/0
r4#sh ip ro
4.0.0.0/24 is subnetted, 1 subnets
C 4.4.4.0 is directly connected, Loopback0
C 194.1.1.0/24 is directly connected, Ethernet0/0
//R4上没有关于AREA 0内的任何路由信息
我们下面在R2、R3上添加Virtual-link的配置：
R2：
router os 1
area 1 virtual-link 3.3.3.3
R3:
router os 1
area 1 virtual-link 2.2.2.2
对比之前的路由信息，看有何区别：
r1#sh ip ro
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
O IA 193.1.1.0/24 [110/20] via 192.1.1.2, 00:00:01, Ethernet0/0
C 192.1.1.0/24 is directly connected, Ethernet0/0
O IA 194.1.1.0/24 [110/30] via 192.1.1.2, 00:00:01, Ethernet0/0
//多了一条194网段的路由，类型IA(区域间)
r2#sh ip ro
2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
C 193.1.1.0/24 is directly connected, Ethernet1/0
C 192.1.1.0/24 is directly connected, Ethernet0/0
O IA 194.1.1.0/24 [110/20] via 193.1.1.3, 00:00:06, Ethernet1/0
//多了一条194网段路由，类型为IA(区域间)
r3#sh ip ro
3.0.0.0/24 is subnetted, 1 subnets
C 3.3.3.0 is directly connected, Loopback0
C 193.1.1.0/24 is directly connected, Ethernet1/0
O 192.1.1.0/24 [110/20] via 193.1.1.2, 00:02:56, Ethernet1/0
C 194.1.1.0/24 is directly connected, Ethernet0/0
//R3的192路由原本为IA类型(区域间)，现在转为O类型(区域内)，说明R3认为自已与192网段是直连的。虚链路相当于将R3直接连接了AREA 0 与 AREA 4区域
r4#sh ip ro
4.0.0.0/24 is subnetted, 1 subnets
C 4.4.4.0 is directly connected, Loopback0
O IA 193.1.1.0/24 [110/20] via 194.1.1.3, 00:03:40, Ethernet0/0
O IA 192.1.1.0/24 [110/30] via 194.1.1.3, 00:03:25, Ethernet0/0
C 194.1.1.0/24 is directly connected, Ethernet0/0
//R4上192路由类型IA(区域间)
最后我们将虚链路效果再与正常连接方式进行一下比对，如下图：
验证如下：
r1#sh ip ro
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
O IA 193.1.1.0/24 [110/20] via 192.1.1.2, 00:00:41, Ethernet0/0
C 192.1.1.0/24 is directly connected, Ethernet0/0
C 192.2.2.0/24 is directly connected, Ethernet1/0
O IA 194.1.1.0/24 [110/20] via 192.2.2.4, 00:00:39, Ethernet1/0
r2#sh ip ro
2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
C 193.1.1.0/24 is directly connected, Ethernet1/0
C 192.1.1.0/24 is directly connected, Ethernet0/0
O 192.2.2.0/24 [110/20] via 192.1.1.1, 00:01:04, Ethernet0/0
O IA 194.1.1.0/24 [110/30] via 192.1.1.1, 00:00:03, Ethernet0/0
r2#
r3#sh ip ro
3.0.0.0/24 is subnetted, 1 subnets