See the solution below.
Explanation:
R1
enable
Config t
Int loop0
Ip ospf 1 area 0
Int et0/0
Ip ospf 1 area 0
Ip ospf network point-to-point
copy run start
R2
Enable
Config t
Int loop0
Ip ospf 1 area 0
Int et0/0
Ip ospf 1 area 0
Ip ospf network point-to-point
Int et0/1
Ip ospf 1 area 0
Ip ospf network point-to-point
copy run start
R3
Enable
Config t
Int loop0
Ip ospf 1 area 0
Int et0/1
Ip ospf 1 area 0
Ip ospf network point-to-point
copy run start
Verification:-
