192.168.1.0/24

192.168.1.0/25 area0

MA骨干 192.168.1.0/27
192.168.1.0/29
192.138.1.8/29
192.168.1.16/29
192.168.1.24/29
用户
192.168.1.32/27 R1
192.168.1.64/27 R2
192.168.1.96/27 R3
192.168.1.128/25 area1
192.168.1.128/27 —P2P 192.168.1.128/30

192.168.1.192/27—R4

区域0的环回地址

[r1-LoopBack0]ip address 192.168.1.34 27

[r2-LoopBack0]ip address 192.168.1.65 27

[r3-LoopBack0]ip add 192.168.1.98 27

给骨干配上IP地址

[r1-GigabitEthernet0/0/0]ip add 192.168.1.1 29

[r2-GigabitEthernet0/0/0]ip address 192.168.1.2 29

[r3-GigabitEthernet0/0/0]ip address 192.168.1.3 29

区域1：
[r4-LoopBack1]IP address 4.4.4.4 24

骨干：
[r4-GigabitEthernet0/0/1]ip address 192.168.1.130 27
[r3-GigabitEthernet0/0/1]ip address 192.168.1.129 27

再使用ospf协议

[R1]ospf 1 router-id 1.1.1.1
[R1-ospf-1]area 0
[R1-ospf-1-area-0.0.0.0]network 192.168.1.0 0.0.0.255

[R2]ospf 1 router-id 2.2.2.2
[R2-ospf-1]area 0
[R2-ospf-1-area-0.0.0.0]network 192.168.1.0 0.0.0.255

[R3]ospf 1 router-id 3.3.3.3
[R3-ospf-1]area 0
[R3-ospf-1-area-0.0.0.0]network 192.168.1.0 0.0.0.255

[R3]ospf 1 router-id 3.3.3.3
[R3-ospf-1]area 1
[R3-ospf-1-area-0.0.0.1]network 192.168.1.129 0.0.0.0

[R4]ospf 1 router-id 4.4.4.4
[R4-ospf-1]area 1
[R4-ospf-1-area-0.0.0.1]network 192.168.1.0 0.0.0.255

R1-3 R3为DR设备，没有BDR

让R3当DR R1R2放弃选举

[r1-GigabitEthernet0/0/0]ospf dr

[r1-GigabitEthernet0/0/0]ospf dr-priority 0

[r2]int g0/0/0

[r2-GigabitEthernet0/0/0]ospf dr

[r2-GigabitEthernet0/0/0]ospf dr-priority 0
缺省路由：

[r4]ospf 1
[r4-ospf-1]default-route-advertise always

认证

[r1]int g0/0/0
[r1-GigabitEthernet0/0/0]ospf authentication-mode md5 1 cipher cisco123

[r2]int g0/0/0
[r2-GigabitEthernet0/0/0]ospf authentication-mode md5 1 cipher cisco123

[r3]int g0/0/0
[r3-GigabitEthernet0/0/0]ospf authentication-mode md5 1 cipher cisco123

[r4]int g0/0/0
[r4-GigabitEthernet0/0/0]ospf authentication-mode md5 1 cipher cisco123
防环
[r3]ip route-static 192.168.1.0 25 NULL 0
[r3]ip route-static 192.168.1.128 25 NULL 0