C:\>ping 200.100.2.3

Pinging 200.100.2.3 with 32 bytes of data:

Reply from 200.100.1.1: Destination host unreachable.
Request timed out.
Reply from 200.100.1.1: Destination host unreachable.
Request timed out.

Ping statistics for 200.100.2.3:
    Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

-------------------
R1#show run
Building configuration...

Current configuration : 975 bytes
!
version 15.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname R1
!
!
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
!
!
!
no ip cef
no ipv6 cef
!
!
!
!
license udi pid CISCO2901/K9 sn FTX1524SXES-
!
!
!
!
!
!
!
!
!
no ip domain-lookup
!
!
spanning-tree mode pvst
!
!
!
!
!
!
interface GigabitEthernet0/0
 ip address 200.100.1.1 255.255.255.0
 duplex auto
 speed auto
!
interface GigabitEthernet0/1
 no ip address
 duplex auto
 speed auto
 shutdown
!
interface Serial0/0/0
 ip address 200.100.12.1 255.255.255.252
 clock rate 64000
!
interface Serial0/0/1
 ip address 200.100.13.1 255.255.255.252
!
interface Vlan1
 no ip address
 shutdown
!
router ospf 1
 router-id 1.1.1.1
 log-adjacency-changes
 passive-interface default
!
ip classless
!
ip flow-export version 9
!
!
!
banner motd ^CPassword access only^C
!
!
!
!
!
line con 0
 password cisco
!
line aux 0
!
line vty 0 4
 login
!
!
!
end
-------------------
R1#show ip route 
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
       * - candidate default, U - per-user static route, o - ODR
       P - periodic downloaded static route

Gateway of last resort is not set

     200.100.1.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.1.0/24 is directly connected, GigabitEthernet0/0
L       200.100.1.1/32 is directly connected, GigabitEthernet0/0
     200.100.12.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.12.0/30 is directly connected, Serial0/0/0
L       200.100.12.1/32 is directly connected, Serial0/0/0
     200.100.13.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.13.0/30 is directly connected, Serial0/0/1
L       200.100.13.1/32 is directly connected, Serial0/0/1
-------------------------
R1#show ip ospf  neighbor 

R1#show ip ospf  dat
R1#show ip ospf  database 
R1#
----------------------------------------------
R1#show ip int brief 
Interface              IP-Address      OK? Method Status                Protocol 
GigabitEthernet0/0     200.100.1.1     YES manual up                    up 
GigabitEthernet0/1     unassigned      YES unset  administratively down down 
Serial0/0/0            200.100.12.1    YES manual up                    up 
Serial0/0/1            200.100.13.1    YES manual up                    up 
Vlan1                  unassigned      YES unset  administratively down down
----------------------------------------

R2#show running-config 
Building configuration...

Current configuration : 966 bytes
!
version 15.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname R2
!
!
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
!
!
!
ip cef
no ipv6 cef
!
!
!
!
license udi pid CISCO2901/K9 sn FTX1524X5M6-
!
!
!
!
!
!
!
!
!
no ip domain-lookup
!
!
spanning-tree mode pvst
!
!
!
!
!
!
interface GigabitEthernet0/0
 ip address 200.100.2.1 255.255.255.0
 duplex auto
 speed auto
!
interface GigabitEthernet0/1
 no ip address
 duplex auto
 speed auto
 shutdown
!
interface Serial0/0/0
 ip address 200.100.12.2 255.255.255.252
!
interface Serial0/0/1
 ip address 200.100.23.1 255.255.255.252
 clock rate 64000
!
interface Vlan1
 no ip address
 shutdown
!
router ospf 1
 router-id 2.2.2.2
 log-adjacency-changes
 passive-interface default
!
ip classless
!
ip flow-export version 9
!
!
!
banner motd ^CPrivate router^C
!
!
!
!
!
line con 0
 password cisco
!
line aux 0
!
line vty 0 4
 login
!
!
!
end
-------------------
R2#show ip route 
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
       * - candidate default, U - per-user static route, o - ODR
       P - periodic downloaded static route

Gateway of last resort is not set

     200.100.2.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.2.0/24 is directly connected, GigabitEthernet0/0
L       200.100.2.1/32 is directly connected, GigabitEthernet0/0
     200.100.12.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.12.0/30 is directly connected, Serial0/0/0
L       200.100.12.2/32 is directly connected, Serial0/0/0
     200.100.23.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.23.0/30 is directly connected, Serial0/0/1
L       200.100.23.1/32 is directly connected, Serial0/0/1
----------------
R2#show ip int brief
Interface              IP-Address      OK? Method Status                Protocol 
GigabitEthernet0/0     200.100.2.1     YES manual up                    up 
GigabitEthernet0/1     unassigned      YES unset  administratively down down 
Serial0/0/0            200.100.12.2    YES manual up                    up 
Serial0/0/1            200.100.23.1    YES manual up                    up 
Vlan1                  unassigned      YES unset  administratively
----------------


R3#show running-config 
Building configuration...

Current configuration : 950 bytes
!
version 15.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname R3
!
!
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
!
!
!
ip cef
no ipv6 cef
!
!
!
!
license udi pid CISCO2901/K9 sn FTX1524ZK6C-
!
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
!
!
!
!
!
!
interface GigabitEthernet0/0
 ip address 200.100.3.1 255.255.255.0
 duplex auto
 speed auto
!
interface GigabitEthernet0/1
 no ip address
 duplex auto
 speed auto
 shutdown
!
interface Serial0/0/0
 ip address 200.100.13.2 255.255.255.252
 clock rate 64000
!
interface Serial0/0/1
 ip address 200.100.23.2 255.255.255.252
!
interface Vlan1
 no ip address
 shutdown
!
router ospf 1
 router-id 3.3.3.3
 log-adjacency-changes
 passive-interface default
!
ip classless
!
ip flow-export version 9
!
!
!
banner motd ^CPassword protected^C
!
!
!
!
!
line con 0
 password cisco
!
line aux 0
!
line vty 0 4
 login
!
!
!
end
------------------
R3#show ip interface brief 
Interface              IP-Address      OK? Method Status                Protocol 
GigabitEthernet0/0     200.100.3.1     YES manual up                    up 
GigabitEthernet0/1     unassigned      YES unset  administratively down down 
Serial0/0/0            200.100.13.2    YES manual up                    up 
Serial0/0/1            200.100.23.2    YES manual up                    up 
Vlan1                  unassigned      YES unset  administratively down down
--------------------

R3#show ip route 
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
       * - candidate default, U - per-user static route, o - ODR
       P - periodic downloaded static route

Gateway of last resort is not set

     200.100.3.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.3.0/24 is directly connected, GigabitEthernet0/0
L       200.100.3.1/32 is directly connected, GigabitEthernet0/0
     200.100.13.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.13.0/30 is directly connected, Serial0/0/0
L       200.100.13.2/32 is directly connected, Serial0/0/0
     200.100.23.0/24 is variably subnetted, 2 subnets, 2 masks
C       200.100.23.0/30 is directly connected, Serial0/0/1
L       200.100.23.2/32 is directly connected, Serial0/0/1