Here are some basic commands to program a Cisco IOS device such as a router or switch.
enable
This bring you into Enable mode
conf t
This brings you into Configure Terminal mode
exit
Takes you back a level
end
Takes you from config mode to privelege exec
reload
Reboots the device
write
Saves the configuration to memory
copy running-config startup-config
Saves the running config to startup config
write erase
Deleted saved configuration
erase startup-config
Deleted startup config
hostname Headquarters-Router
This lets you change the hostname to Headquarters-Router
enable secret level 15 52##tgh**
This sets the enable secret to 52##tgh** and sets that password to level 15 the highest level. When viewing the configs the password will show as encrypted
int fa 0/1
This will get you into the interface level configuration for FastEthernet 0/1
no shut
This brings up an interface, on Cisco devices all ports are shutdown by default
banner login #No unathorized access allowed#
This sets the login banner that will be seen of someone telnet's in but not if using SSH.
banner motd #No unathorized access allowed#
This sets the motd banner that will be seen after connecting.