一．實驗拓撲圖
二．實驗目的
1． 起用ospf協議，進程號100
2． 啓用認證 md5
3． 啓用r2做DR，r3做BDR
4． 設r1的cost值爲50
三．實驗命令
r1；
en
config t
int e0
ip add 1.1.1.1 255.255.255.0
no shut
int loop 1
ip add 4.4.4.4 255.255.255.0
exit
r2:
en
config t
int e0
ip add 1.1.1.2 255.255.255.0
no shut
int loop 1
ip add 2.2.2.2 255.255.255.0
exit
r3:
en
config t
int e0
ip add 1.1.1.3 255.255.255.0
int loop 1
ip add 3.3.3.3 255.255.255.0
exit
啓用ospf協議：
r1:
config t
router ospf 100
net 1.1.1.1 0.0.0.0 area 0
net 4.4.4.0 0.0.0.255 area0
exit
r2:
config t
router ospf 100
net 1.1.1.2 0.0.0.0 area 0
net 2.2.2.0 0.0.0.255 area 0
exit
r3:
config t
router ospf 100
net 1.1.1.3 0.0.0.0 area 0
net 3.3.3.3 0.0.0.255 area 0
exit
啓用md5認證
r1：config t
router ospf 100
area 0 authentication message-digest
int e0
ip ospf message-digest-key 1 md5 cisco
r2：config t
router ospf 100
area 0 authentication message-digest
int e0
ip ospf message-digest-key 1 md5 cisco
r2：config t
router ospf 100
area 0 authentication message-digest
int e0
ip ospf message-digest-key 1 md5 cisco
設置r2爲DR，設置r3爲BDR
r2 ；
config t
int e0
ip ospf priority 100
exit
r3:
config t
int e0
ip ospf priority 50
設置r1的cost值爲50
r1:
config t
int e0
ip ospf cost 50
exit