R1
interface FastEthernet0/0
ip address 192.168.0.1 255.255.255.0
duplex full
!
interface FastEthernet1/0
ip address 172.16.1.1 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet1/1
ip address 172.16.3.1 255.255.255.0
duplex auto
speed auto
!
router ospf 1
network 172.16.1.0 0.0.0.255 area 50
network 172.16.3.0 0.0.0.255 area 50
network 192.168.0.0 0.0.0.255 area 50
R2
interface FastEthernet0/0
ip address 192.168.1.1 255.255.255.0
duplex full
!
interface FastEthernet1/0
ip address 172.16.1.2 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet1/1
ip address 172.16.2.1 255.255.255.0
duplex auto
speed auto
interface FastEthernet1/0
ip address 172.16.2.2 255.255.255.0
duplex auto
speed auto
!
router ospf 1
network 172.16.1.0 0.0.0.255 area 50
network 172.16.2.0 0.0.0.255 area 50
network 192.168.1.0 0.0.0.255 area 50
R3
interface FastEthernet1/1
ip address 172.16.3.2 255.255.255.0
duplex auto
speed auto
!
router ospf 1
log-adjacency-changes
network 172.16.2.0 0.0.0.255 area 50
network 172.16.3.0 0.0.0.255 area 50
!
router ospf 1
network 172.16.2.0 0.0.0.255 area 50
network 172.16.3.0 0.0.0.255 area 50