实验名称：作OSPF的AD值修改选择路径
实验拓扑

实验步骤：
配置IP地址
R1:
enable
conf t
int f 0/0
no shu
ip add 192.168.12.1 255.255.255.0
exit
int l 0
ip add 10.10.1.1 255.255.255.0
exit

R2:
enable
conf t
int f0/1
no shu
ip add 192.168.12.2 255.255.255.0
exit
int l 0
ip add 10.10.2.2 255.255.255.0
exit
int f0/0
no shu
ip add 192.168.23.2 255.255.255.0
exit

R3:
enable
conf t
int f0/1
no shu
ip add 192.168.23.3 255.255.255.0
exit
int l 0
ip add 10.10.3.3 255.255.255.0
exit
int f0/0
no shu
ip add 192.168.34.3 255.255.0
exit

R4:
enable
conf t
int f0/1
no shu
ip add 192.168.34.4 255.255.255.0
exit
int l 0
ip add 10.10.4.4 255.255.255.0
exit

配置ospf

R1：
router os 1
router-id 1.1.1.1
net 192.168.12.0 0.0.0.255 ar 12
net 10.10.1.0 0.0.0.255 ar 12
exit

R2:
router os 1
router-id 2.2.2.2
net 192.168.12.0 0.0.0.255 ar 12
net 192.168.23.0 0.0.0.255 ar 0
net 10.10.2.0 0.0.0.255 ar 0
exit

R3:
router os 1
router-id 3.3.3.3
net 192.168.23.0 0.0.0.255 ar 0
net 10.10.3.0 0.0.0.255 ar 0
net 192.168.34.0 0.0.0.255 ar 0
exit

R4:
router os 1
router-id 4.4.4.4
net 192.168.34.0 0.0.0.255 ar 0
net 10.10.4.0 0.0.0.255 ar 0
exit

配置路由AD值属性，在R2与R4上建66.1.1.1 修改R4的AD为100，让
路由往R4走

在R2与R4上添加66.1.1.1
R2:
int l 66
ip add 66.1.1.1 255.255.255.0
exit
router os 1
router-id 2.2.2.2
net 66.1.1.1 0.0.0.0 ar 0
exit

R4:
int l 66
ip add 66.1.1.1 255.255.255.0
exit
router os 1
router-id 4.4.4.4
net 66.1.1.1 0.0.0.0 ar 0
exit

思路：在R3上做ACL允许 ，修改AD值

R3:

ip access-list standard 66
10 permit 66.1.1.1
exit
router os 1
distance 100 4.4.4.4 0.0.0.0 66
exit
clear ip os process
y
show ip route os
show ip os database s