Single Area OSPF Configuration Example [Packet Tracer]

Contents

Topology:

Configurations of each node:
Verification:

Topology:

Configurations of each node:

Router1:


R1#sh run

Building configuration...

Current configuration : 731 bytes

!

version 15.4

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname R1

ip cef

no ipv6 cef

!

spanning-tree mode pvst

!

interface Loopback0

ip address 1.1.1.1 255.255.255.255

!

interface GigabitEthernet0/0/0

ip address 10.1.1.1 255.255.255.0

duplex auto

speed auto

!

interface GigabitEthernet0/0/1

no ip address

duplex auto

speed auto

shutdown

!

interface Vlan1

no ip address

shutdown

!

router ospf 1

log-adjacency-changes

network 10.1.1.1 0.0.0.0 area 0

network 1.1.1.1 0.0.0.0 area 0

!

ip classless

!

ip flow-export version 9

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

Router 2 Configuration:

R2#sh run

Building configuration...

Current configuration : 778 bytes

!

version 15.4

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname R2

!

ip cef

no ipv6 cef

!

spanning-tree mode pvst

!

interface Loopback0

ip address 2.2.2.2 255.255.255.255

!

interface GigabitEthernet0/0/0

ip address 10.1.1.2 255.255.255.0

duplex auto

speed auto

!

interface GigabitEthernet0/0/1

ip address 10.1.2.1 255.255.255.0

duplex auto

speed auto

!

interface Vlan1

no ip address

shutdown

!

router ospf 1

log-adjacency-changes

network 2.2.2.2 0.0.0.0 area 0

network 10.1.1.0 0.0.0.255 area 0

network 10.1.2.0 0.0.0.255 area 0

!

ip classless

!

ip flow-export version 9

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

Router 3 Configuration:

R3#sh run

Building configuration...

Current configuration : 776 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname R3

!

!

ip cef

no ipv6 cef

!

license udi pid CISCO1941/K9 sn FTX15242C77

!

spanning-tree mode pvst

!

interface Loopback0

ip address 3.3.3.3 255.255.255.255

ip ospf 1 area 0

!

interface GigabitEthernet0/0

ip address 10.1.3.1 255.255.255.0

ip ospf 1 area 0

duplex auto

speed auto

!

interface GigabitEthernet0/1

ip address 10.1.2.2 255.255.255.0

ip ospf 1 area 0

duplex auto

speed auto

!

interface Vlan1

no ip address

shutdown

!

router ospf 1

log-adjacency-changes

!

ip classless

!

ip flow-export version 9

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

Router 4 Configuration:

R4#sh run

Building configuration...

Current configuration : 752 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname R4

!

ip cef

no ipv6 cef

!

license udi pid CISCO1941/K9 sn FTX152462Z0

!

!

spanning-tree mode pvst

!

!

interface Loopback0

ip address 4.4.4.4 255.255.255.255

!

interface GigabitEthernet0/0

ip address 10.1.3.2 255.255.255.0

duplex auto

speed auto

!

interface GigabitEthernet0/1

no ip address

duplex auto

speed auto

shutdown

!

interface Vlan1

no ip address

shutdown

!

router ospf 1

log-adjacency-changes

network 0.0.0.0 255.255.255.255 area 0

!

ip classless

!

ip flow-export version 9

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

Verification:

R1#sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

2.2.2.2 1 FULL/DR 00:00:38 10.1.1.2 GigabitEthernet0/0/0

R2#sh ip ospf neighbor

---------------------------

Neighbor ID Pri State Dead Time Address Interface

1.1.1.1 1 FULL/BDR 00:00:33 10.1.1.1 GigabitEthernet0/0/0

3.3.3.3 1 FULL/DR 00:00:33 10.1.2.2 GigabitEthernet0/0/1

R2#

-------------------------

R3#sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

4.4.4.4 1 FULL/DR 00:00:32 10.1.3.2 GigabitEthernet0/0

2.2.2.2 1 FULL/BDR 00:00:32 10.1.2.1 GigabitEthernet0/1

R3#

-------------------------

R4#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

3.3.3.3 1 FULL/BDR 00:00:34 10.1.3.1 GigabitEthernet0/0

After configuring Single Area OSPF in the 4 routers, we can check that R1 know about the other network advertised through OSPF, and its the same with all the nodes:

R1#sh 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

1.0.0.0/32 is subnetted, 1 subnets

C 1.1.1.1/32 is directly connected, Loopback0

2.0.0.0/32 is subnetted, 1 subnets

O 2.2.2.2/32 [110/2] via 10.1.1.2, 00:14:07, GigabitEthernet0/0/0

3.0.0.0/32 is subnetted, 1 subnets

O 3.3.3.3/32 [110/3] via 10.1.1.2, 00:14:07, GigabitEthernet0/0/0

4.0.0.0/32 is subnetted, 1 subnets

O 4.4.4.4/32 [110/4] via 10.1.1.2, 00:14:07, GigabitEthernet0/0/0

10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks

C 10.1.1.0/24 is directly connected, GigabitEthernet0/0/0

L 10.1.1.1/32 is directly connected, GigabitEthernet0/0/0

O 10.1.2.0/24 [110/2] via 10.1.1.2, 00:14:07, GigabitEthernet0/0/0

O 10.1.3.0/24 [110/3] via 10.1.1.2, 00:14:07, GigabitEthernet0/0/0

R1#