How to move between Cisco Router Interfaces

To move to a Cisco router interface, use the following commands

HappyRouter>enableHappyRouter#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#interface fa0/1
HappyRouter(config-if)#

To move to a Serial interface from FastEthernet interface use a command similar to this

HappyRouter>enableHappyRouter#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#interface fa0/1
HappyRouter(config-if)#exit
Router(config)#Serial0/1
HappyRouter(config-if)