HP 7102dl - ProCurve Secure Router Configuration Manual page 779

N o t e
In the example configuration commands, note that the network commands
enable OSPF on the /20 subnets on which the ABR interfaces reside. The area
<area ID> range commands, on the other hand, specify the range of four /
20 subnets that belong to each area. A range of four subnets subtracts two
from the original prefix length of 20, for 18 bits. The corresponding subnet
mask is 255.255.192.0
To configure ABR A in Figure 15-12, you would enter the following commands
from the OSPF configuration mode context:
ProCurve(config-ospf)# network 172.16.16.0 0.0.15.255 area 0
ProCurve(config-ospf)# network 172.16.64.0 0.0.15.255 area 1
ProCurve(config-ospf)# network 172.16.128.0 0.0.15.255 area 2
ProCurve(config-ospf)# network 172.16.192.0 0.0.15.255 area 3
ProCurve(config-ospf)# area 1 stub
ProCurve(config-ospf)# area 2 stub no-summary
ProCurve(config-ospf)# area 0 range 172.16.0.0 255.255.192.0
ProCurve(config-ospf)# area 1 range 172.16.64.0 255.255.192.0
ProCurve(config-ospf)# area 2 range 172.16.128.0 255.255.192.0
ProCurve(config-ospf)# area 3 range 172.16.192.0 255.255.192.0
ABR A's interfaces would have the IP addresses shown in Figure 15-13.
!
interface eth 0/1
ip address 172.16.16.1 255.255.240.0
!
interface fr 1.101 point-to-point
ip address 172.16.64.2 255.255.240.0
!
interface fr 1.102 point-to-point
ip address 172.16.128.2 255.255.240.0
!
interface fr 1.103 point-to-point
ip address 172.16.192.2 255.255.240.0
Figure 15-13. IP Addresses of Router A's Interfaces
Take care to define the network that the ABR and the stub router have in
common as part of the stub area. Otherwise, each stub router becomes an
ABR. Because routers in the same area must use the same database, the
routers in the stub areas would then hold all area 0 information (or, in other
words, the topology of the entire WAN). You have, in effect, negated the
partitioning.
IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring OSPF
15-53