#Configuring OSPF routing protocol
router ospf 1
network 192.168.12.0 0.0.0.255 area 0
28.4.5 OSPF ABR, ASBR Configuration
Examples
Configuration requirements:
Four devices form an OSPF routing area. Networks 192.168.12.0/24 and 192.168.23.0/24
belong to area 0, while network 192.168.34.0/24 belongs to area 34. Figure 28-5 shows the
IP address allocation and connection of the equipment.
Figure 28-5 Example of configuring OSPF ABR and ASBR
As is shown in above figure, the device A and device B are of the area internal device s, the
device C is of the ABRs, and the device D is of the ASBRs. 200.200.1.0/24 and
172.200.1.0/24 are the networks outside the OSPF routing area. Configure various devices
so that all OSPF routers can learn the external routes, which must carry the ―34‖ tag and be
Type-I.
Concrete Configuration of Devices
When the OSPF redistributes the routes of other sources, the default type is type II and it
does not carry any tag.
Configuration of Device A:
#Configuring Ethernet interface
interface FastEthernet0/0
ip address 192.168.12.1 255.255.255.0
#Configuring OSPF routing protocol