Define hostname
It is very useful define the name of your Cisco switch/router. To do it:

Enable administrative privilege
Router>en
Enter the configuration mode:
Router#configure terminal
Define the hostname (the name router is changed to Ciscozine)
Router(config)#hostname Ciscozine
Ciscozine(config)#

Assign the privileged level secret
The enable secret password allows you to enter enable mode (sometimes referred to as privileged mode or privileged-EXEC mode). To set a secret password:

Enable administrative privilege
Ciscozine>en
Enter the configuration mode:
Ciscozine#configure terminal
Define the privileged-EXEC mode password; remember to use a strong password (combine letters, numbers, nd symbols). The enable secret command uses a one-way encryption hash based on Message Digest 5 (MD5)
Ciscozine(config)#enable secret C1sc0z$n3

Secure console port
For security reasons, you must define a console password:

Enable administrative privilege
Ciscozine>en
Enter the configuration mode:
Ciscozine#configure terminal
Enter in the console configuration
Ciscozine(config)#line console 0
Define your console password
Ciscozine(config-line)#password g4S$%A2
Enable the password defined
Ciscozine(config-line)#login
Use the “logging synchronous” command, so the messages appear only after you press Return
Ciscozine(config-line)#logging synchronous

Secure VTY lines
For security reasons, you must define a vty line password. The vty lines defines the password needed for a remote access (telnet, ssh, …)

Enable administrative privilege
Ciscozine>en
Enter the configuration mode:
Ciscozine#configure terminal
Enter the vty line configuration. The “0 4″ define the “first last” line number; in this case there are 5 allowed sessions.
Ciscozine(config)#line vty 0 4
Define your vty lines password
Ciscozine(config-line)#password g%S$%Aa3
Enable