The third experiment OSPF

Topology design ：

  Design ip：

192.168.1.0 /24

Three loops ：

192.168.1.0 /26    192.168.1.64 /26    192.168.1.128 /26

A backbone ：

192.168.1.192/26       192.168.1.0/30

ospf Basic configuration ：r1----r4

eg:   [r2]ospf 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

: take r1r2r3（g0/0/0） Unconfigured area 0  take r3（g0/0/1）r4 Configure as area  

[r3]ospf router-id 4.4.4.4

[r3-ospf-1]area 1
[r3-ospf-1-area-0.0.0.1]network 192.168.1.0 0.0.0.3

Interference in elections ： r1-r3 r3 by dr equipment     nothing bdr equipment

take r3 to 0/0/0 The priority of the port is changed to 3

[r3]interface GigabitEthernet 0/0/0

[r3-GigabitEthernet0/0/0]ospf dr-priority  3   Modify interface priority

Empathy ： take r1,r2 Change it to 0

r4 Loopback undeclared , Present division r4 Loopback failure ping Same as , The rest are OK ：(r1ping  r2 And r3 All possible )

 

  Ensure more heart safety ： authentication

[r1-GigabitEthernet0/0/0]ospf authentication-mode md5  1 cipher 123456

[r2-GigabitEthernet0/0/0]ospf authentication-mode md5  1 cipher 123456

[r3-GigabitEthernet0/0/0]ospf authentication-mode md5  1 cipher 123456

[r3-GigabitEthernet0/0/1]ospf authentication-mode md5  1 cipher 123456

[r4-GigabitEthernet0/0/0]ospf authentication-mode md5  1 cipher 123456

r4： Default route

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

Set the empty interface , Avoid loops ,

[r2]ip route-static 192.168.1.0 24 NULL 0

[r2]ip route-static 192.168.1.0 24 NULL 0

[r3]ip route-static 192.168.1.0 24 NULL 0

After completion ping4.4.4.1 （isp） 

Reduce the number of routes , Regional summary ：

[r3-ospf-1-area-0.0.0.0]abr-summary 192.168.1.0 255.255.255.0

Network wide accessibility .