RA#sh run
!
interface Loopback0
ip address 1.1.1.1 255.255.255.0
ip ospf network point-to-point
!
interface Serial1/0
ip address 10.0.0.1 255.255.255.0
ip ospf message-digest-key 1 md5 123
serial restart-delay 0
!
interface Serial1/2
ip address 12.0.0.2 255.255.255.0
ip ospf message-digest-key 1 md5 123
serial restart-delay 0
!
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
area 0 authentication message-digest
network 1.0.0.0 0.0.0.255 area 0
network 10.0.0.0 0.0.0.255 area 0
network 12.0.0.0 0.0.0.255 area 0
!
End
RB#sh run
!
interface Loopback0
ip address 2.2.2.2 255.255.255.0
ip ospf network point-to-point
!
interface FastEthernet0/0
no ip address
shutdown
duplex half
!
interface Serial1/0
ip address 10.0.0.2 255.255.255.0
ip ospf message-digest-key 1 md5 123
serial restart-delay 0
!
interface Serial1/1
ip address 11.0.0.1 255.255.255.0
ip ospf message-digest-key 1 md5 123
serial restart-delay 0
!
!
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
area 0 authentication message-digest
network 2.0.0.0 0.0.0.255 area 0
network 10.0.0.0 0.0.0.255 area 0
network 11.0.0.0 0.0.0.255 area 0
!
!
End
RC#sh run
!
interface Loopback0
ip address 3.3.3.3 255.255.255.0
ip ospf network point-to-point
!
!
interface Serial1/1
ip address 11.0.0.2 255.255.255.0
ip ospf message-digest-key 1 md5 123
serial restart-delay 0
!
interface Serial1/2
ip address 12.0.0.1 255.255.255.0
ip ospf message-digest-key 1 md5 123
serial restart-delay 0
!
!
router ospf 1
router-id 3.3.3.3
log-adjacency-changes
area 0 authentication message-digest
network 3.0.0.0 0.0.0.255 area 0
network 11.0.0.0 0.0.0.255 area 0
network 12.0.0.0 0.0.0.255 area 0
!
!
end