Cisco OSPF Configuration | How To Configure OSPF

Configure OSPF on Cisco Router

In this lab, I am gonna teach you Cisco OSPF Configuration | How To Configure OSPF

Cisco OSPF Configuration – VLSM

Given network: 200.150.100.0

Required hosts on Router 1: 14

Required hosts on Router 2: 6

Cisco OSPF Configuration | How To Configure OSPF

R1<= 14

14<= 2n – 2

14<= 24 – 2

14<= 16 – 2

14<= 14

Total number of network bits = 32

32 – n = 32 – 4 = 28 (CIDR value of given network i.e. Router 1)

i.e. 200.150.100.0/28

N.S.M = 11111111. 11111111. 11111111.11110000

                        = 255.255.255.240

Block size        = 256 – N.S.M

                        = 256 – 240 = 16

Note: Add this block size in given network so that we can get our new network for Router 2.

So the new network is 200.150.100.16/?

Now find FVH, LVH, and broadcast address

Given Network2001501000
First Valid Host-FVH2001501001
Last Valid Host-LVH20015010014
Broadcast20015010015
New Network20015010016

R2<= 6

6<= 2n – 2

6<= 23 – 2

6<= 8 – 2

6<= 6

Total number of network bits = 32

32 – n = 32 – 3 = 29 (CIDR value of new network i.e. Router 2)

i.e. 200.150.100.16/29

N.S.M = 11111111. 11111111. 11111111.11111000

                        = 255.255.255.248

Block size        = 256 – N.S.M

                        = 256 – 248 = 8

Note: Add this block size in given network so that we can get our new network for Router 1 and 2 (Virtual Network).

So the new network is 200.150.100.24/?

Now find FVH, LVH, and broadcast address

Given Network20015010016
First Valid Host-FVH20015010017
Last Valid Host-LVH20015010022
Broadcast20015010023
New Network20015010024

Router 1 & 2 <= 2 hosts (we required only two IP to connect 2 routers)

2 <= 2n – 2

2 <= 22 – 2

2 <= 4 – 2

2 <= 2

Total number of network bits = 32

32 – n = 32 – 2 = 30 (CIDR of Virtual network (R1&R2)

i.e. 200.150.100.24/30

N.S.M = 11111111.11111111.11111111.11111100

= 255.255.255.252

Block Size        = 256 – N.S.M

= 256 – 252 = 4

Note: Add this block size in given network so that we can get our new network for Router 3. This network can be used in future.

so the new network is 200.150.100.28/?

Now find FVH, LVH and Broadcast address

Given Network20015010024
First Valid Host-FVH20015010025
Last Valid Host-LVH20015010026
Broadcast20015010027
New Network20015010028

Basic Configuration on Router 1  

Basic Configuration on Router 1  

Router>enable
Router#configure terminal
Router(config)#hostname R1
R1(config)#interface fastEthernet 0/0
R1(config-if)#ip address 200.150.100.1         255.255.255.240
R1(config-if)#no shutdown
R1(config-if)#exit  

R1(config)#interface serial 0/0/0
R1(config-if)#ip address 200.150.100.25       255.255.255.252
R1(config-if)#clock rate 64000
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#exit R1#write

Basic Configuration on Router 2

Basic Configuration on Router 2  

Router>enable
Router#configure terminal
Router(config)#hostname R2
R2(config)#interface fastEthernet 0/0
R2(config-if)#ip address 200.150.100.17       255.255.255.248
R2(config-if)#no shutdown
R2(config-if)#exit  

R2(config)#interface serial 0/1/0
R2(config-if)#ip address 200.150.100.26       255.255.255.252
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#exit
R2#write
Cisco OSPF Configuration | How To Configure OSPF

OSPF Single Area Configuration on Router 1  

OSPF Single Area Configuration on Router 1  

R1>enable  
R1#show ip route connected  
C   200.150.100.0/28  is directly connected, FastEthernet0/0  
C   200.150.100.24/30  is directly connected, Serial0/0/0  

R1#configure terminal
R1(config)#router ospf 10
R1(config-router)#network 200.150.100.0             0.0.0.15           area 1
R1(config-router)#network 200.150.100.24           0.0.0.3             area 1
R1(config-router)#exit
R1(config)#exit
R1#write

OSPF Single Area Configuration on Router 2

OSPF Single Area Configuration on Router 2  

R2>enable  
R2#show ip route connected  
C   200.150.100.16/29  is directly connected, FastEthernet0/0  
C   200.150.100.24/30  is directly connected, Serial0/1/0  

R2#configure terminal
R2(config)#router ospf 10
R2(config-router)#network 200.150.100.16              0.0.0.7             area 1
R2(config-router)#network 200.150.100.24              0.0.0.3             area 1
R2(config-router)#exit
R2(config)#exit
R2#write

Verification on Router 1  

Verification on Router 1  

R1#show ip route     
200.150.100.0/24 is variably subnetted, 3 subnets, 3 masks
C       200.150.100.0/28 is directly connected, FastEthernet0/0
O       200.150.100.16/29 [110/65] via 200.150.100.26, 00:00:30, Serial0/0/0 C       200.150.100.24/30 is directly connected, Serial0/0/0

Verification on Router 2

Verification on Router 2  

R2#show ip route     
200.150.100.0/24 is variably subnetted, 3 subnets, 3 masks
O       200.150.100.0/28 [110/65] via 200.150.100.25, 00:01:02, Serial0/1/0 C       200.150.100.16/29 is directly connected, FastEthernet0/0
C       200.150.100.24/30 is directly connected, Serial0/1/0
Cisco OSPF Configuration | How To Configure OSPF

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