OSPF虚链路的配置

原创

yasa98 2008-08-18 15:59:03 博主文章分类：实验 ©著作权

文章标签 配置职场 OSPF 休闲虚链路 文章分类 网络安全

©著作权归作者所有：来自51CTO博客作者yasa98的原创作品，请联系作者获取转载授权，否则将追究法律责任

本实验拓扑示意图如下：

配置验证一个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#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

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）

现在将虚链路效果再与正常连接方式进行一下比对，如图：

验证：

    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
    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, 00:01:31, Ethernet1/0
    O IA 192.2.2.0/24 [110/30] via 193.1.1.2, 00:01:15, Ethernet1/0
    O IA 194.1.1.0/24 [110/40] via 193.1.1.2, 00:00:15, Ethernet1/0

    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 [110/30] via 192.2.2.1, 00:00:39, Ethernet1/0
    O    192.1.1.0/24 [110/20] via 192.2.2.1, 00:01:37, Ethernet1/0
    C    192.2.2.0/24 is directly connected, Ethernet1/0
    C    194.1.1.0/24 is directly connected, Ethernet0/0

r5#sh ip ro

        5.0.0.0/24 is subnetted, 1 subnets
    C       5.5.5.0 is directly connected, Loopback0
    O IA 193.1.1.0/24 [110/40] via 194.1.1.4, 00:00:52, Ethernet0/0
    O IA 192.1.1.0/24 [110/30] via 194.1.1.4, 00:00:52, Ethernet0/0
    O IA 192.2.2.0/24 [110/20] via 194.1.1.4, 00:00:52, Ethernet0/0
    C    194.1.1.0/24 is directly connected, Ethernet0/0