Experimental topology:
Experimental requirements:
4 Configuration Requirements:
R1：int g/0/0
ospf dr-priority 0
[Priority is 0 or modify the network type is changed to P-2-P, will not vote DR, BDR]
5 configuration requirements:
R 3 OSPF 1
a 1
ssa
ssa no-summary
R 4 OSPF 1
a 1
ssa
ssa no-summary
R4 is arranged before the LSDB nssa:
LSDB modified after:
9 configuration requirements:
R3：int g/0/1
ospf dr-priority 100
Modify the interface priority to a priority of 0 will lose eligibility to participate in the DR.
Maximum priority DR, equal priority, see route-id. If, after the priority of the interface changes,
still can not successfully be the DR, then you can restart the OSPF process, shutdown or out of the interface and then no shutdown.
】
Each routing device configuration:
R5：
interface GigabitEthernet0/0/0
ip address 192.168.10.1 255.255.255.0
ospf dr-priority 0
#
interface LoopBack0
ip address 100.1.1.1 255.255.255.0
#
ospf 1 router-id 100.1.1.1
area 0.0.0.2
network 100.1.1.0 0.0.0.255
network 192.168.10.0 0.0.0.255
#
R1：
interface GigabitEthernet0/0/0
ip address 192.168.10.2 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 192.168.20.1 255.255.255.0
#
interface LoopBack0
ip address 1.1.1.1 255.255.255.0
#
ospf 1 router-id 1.1.1.1
area 0.0.0.0
network 192.168.20.0 0.0.0.255
area 0.0.0.2
network 1.1.1.0 0.0.0.255
network 192.168.10.0 0.0.0.255
#
R2：
interface GigabitEthernet0/0/0
ip address 192.168.20.2 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 192.168.30.1 255.255.255.0
#
interface LoopBack0
ip address 2.2.2.2 255.255.255.0
#
ospf 1 router-id 2.2.2.2
area 0.0.0.0
network 2.2.2.0 0.0.0.255
network 192.168.20.0 0.0.0.255
network 192.168.30.0 0.0.0.255
R3：
interface GigabitEthernet0/0/0
ip address 192.168.30.2 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 192.168.40.1 255.255.255.0
ospf dr-priority 100
#
interface LoopBack0
ip address 3.3.3.3 255.255.255.0
#
ospf 1 router-id 3.3.3.3
area 0.0.0.0
network 3.3.3.0 0.0.0.255
network 192.168.30.0 0.0.0.255
area 0.0.0.1
abr-summary 192.168.32.0 255.255.224.0
network 192.168.40.0 0.0.0.255
nssa no-summary
#
R4：
interface GigabitEthernet0/0/0
ip address 192.168.40.2 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 192.168.50.1 255.255.255.0
#
interface LoopBack0
ip address 4.4.4.4 255.255.255.0
#
ospf 1 router-id 4.4.4.4
import-route rip 1 route-policy 1
area 0.0.0.1
network 4.4.4.0 0.0.0.255
network 192.168.40.0 0.0.0.255
nssa no-summary
#
rip 1
version 2
network 192.168.50.0
import-route ospf 1 route-policy 1
#
R6：
interface GigabitEthernet0/0/0
ip address 192.168.50.2 255.255.255.0
#
interface LoopBack0
ip address 200.1.1.1 255.255.255.0
#
rip 1
version 2
network 192.168.50.0
network 200.1.1.0
#