Initial Configurations

Setting Hostname:
Router(Config)# hostname RTR
RTR(Config)#

Putting IP address to an interface:
RTR(Config)# interface f0/0             -----> 0 = Zero
RTR(Config-if)# ip address 192.168.1.1 255.255.255.0
RTR(Config-if)# no shutdown     ----> Activating the interface
RTR(Config-if)# exit
RTR(Config)#

Configuring Console:
RTR(Config)# line console 0                  -----> 0 = Zero
RTR(Config-line)# password console
RTR(Config-line)# exit

Securing VTY ports:
RTR(Config)# line vty 0 4
RTR(Config-line)# password telnet
RTR(Config-line)# exit

Securing Priviledge Mode:
RTR(Config)# enable secret cisco
or, RTR(Config)# enable password cisco

Saving Router's Configuration:
RTR# copy running-config startup-config
or,
RTR# write
or,
RTR# write memory