Password Encryption on a Router/Switch - Networking How-to

Password Encryption

Router(config)#service password-encryption	Applies a weak encryption to passwords
Router(config)#enable password cisco	Sets enable password to cisco
Router(config)#line con 0	...
Router(config-line)#password Cisco	Continue setting passwords as above
	...
Router(config)#no service password-encryption	Turns off password encryption

Caution:

If you have turned on service password encryption, used it, and then turned it off, any passwords that you have encrypted will stay encrypted. New passwords will remain unencrypted.