how to configure loopback interface in Cisco Router

Step 1 – at fast we will take two router and two pc and configure ip address like below image 

Step 2 IP address configuration on router 0 
Router>enable
Router#config terminal
Router(config)#hostname r1
r1(config)#interface FastEthernet0/0
r1(config-if)#ip address 1.0.0.1 255.0.0.0
r1(config-if)#no shutdown
r1(config-if)#exit
r1(config)#interface Serial0/0/0
r1(config-if)#ip address 2.0.0.1 255.0.0.0
r1(config-if)#no shutdown
r1(config-if)#exit
r1(config)#int loop 3
r1(config-if)#ip address 4.0.0.1 255.0.0.0
r1(config-if)#exit
r1(config)#int loop 4
r1(config-if)#ip address 5.0.0.1 255.0.0.0

Step 3  IP address Configuration for Router 1

Router>enable
Router#config terminal
Router(config)#hostname r2
r2(config)#interface FastEthernet0/0
r2(config-if)#ip address 3.0.0.1 255.0.0.0
r2(config-if)#no shutdown
r2(config-if)#exit
r2(config)#interface Serial0/0/0
r2(config-if)#ip address 2.0.0.2 255.0.0.0
r2(config-if)#no shutdown
r2(config-if)#exit
r2(config)#int loop 1
r2(config-if)#ip address 6.0.0.1 255.0.0.0
r2(config-if)#exit
r2(config)#int loop 2
r2(config-if)#ip address 7.0.0.1 255.0.0.0
r2(config-if)#exit

Step 4 Static routing for router 0

r1(config)#ip route 3.0.0.1 255.0.0.0 2.0.0.2
r1(config)#ip route 6.0.0.0 255.0.0.0 2.0.0.2
r1(config)#ip route 7.0.0.0 255.0.0.0 2.0.0.2

Step 5 Static routing for router 1

r1(config)#ip route 1.0.0.0 255.0.0.0 2.0.0.1
r1(config)#ip route 4.0.0.0 255.0.0.0 2.0.0.1
r1(config)#ip route 5.0.0.0 255.0.0.0 2.0.0.1

Now your work is Complete you can ping to each ip address. if you have any problem in this process please comments here i will solve your problem. If you want You can also download loop back ip lab through this likn   

Thank you

by Vishnu Sharma