CCNA-Notes/04. Intro to the CLI.md

id, aliases, tags

id	aliases	tags
04. Intro to the CLI		CCNA

Intro to the CLI, Introduction to the CISCO IOS

How to connect to a Cisco device

connect via a console port with RJ45 or USB-mini Use a Rollover cable

Terminal Emulator

access with a Terminal Emulator (ex: PuTTy)

default configuration:

speed: 9600 data bits: 8 stop bits: 1 parity: none flow control: none

user Exec Mode

User Exec mode is very limited. Users can look at some things, but can't make any changes to the configuration. also called 'user mode'

Router>

Privileged Exec mode

Provide complete access to view the device's configuration, restart the device, etc.. Cannot change the configuration, but can change the time on the device, save the configuration, etc...

Router>enable
Router#

? "list command available"

for the full list of all the command available just type ?

Router>?
Router#?

// to display abiguous command
Router>e?
enable    exit

Global configuration mode

To enter configuration mode

Router#configure termianl
Router(config)#

//shortcut

Router>enable
Router#con?
configure     connect
Router#conf t?
terminal
Router#conf t
Router(config)#

Enable password

To enable password in the config mode passwords are case-sensitive if you type 3 time a false password it exit

Router (config)# enable password |your password|
// ex:
Router (config)# enable password CCNA
Router (config) #exit
Router>enable
Password:
Router#

Running-config / startup-config

There are two separate configuration files kept on the device at once.

• Running-config : the current, active configuration file on the device. As you enter commands in the CLI, you edit the active configuration.
• Startup-config : The configuration file that will be loaded upon restart of the device.

Show running-config/ show startup-config

Router#show running-config

Router#show startup-config

Saving the configureation

there are three ways to save the running configuration to the startup-config

//1.
Router#write

//2.
Router#write memory

//3.
Router#copy running-config startup-config

Service password-encryption

for security purpose always save the password with password-encryption enable

Router (config) # service password-encryption

//when using the show running-config it return
enable password 7 |hash of the password|

note: the number 7 is the type of encryption used for the encryption
7 is the proprietary Cisco encryption [[algorithm]]
with the first method is easy to decrypt the password with a deencryption tool

Enable secret

for more security use the method enable secret

Router (config) #enable secret |Your password|
ex:
Router (config) #enable secret Cisco
//when using the show running-config it return
enable secret 5 |hash of the password|

note : number 5 is the number for the [[MD5]] encryption

sercice password-encryption

if you enable service password-encryption

• current passwords will be encrypted
• future passwords will be encrypted
• the enbalbe secret will not be effected if you disables service password-encryption
• current passwords will not be decrypted
• future passwords will not be decrypted
• the enable secret will not be effected

Canceling commands

for canceling a command with the device type no + the name of the command

Router (config) #no service password-encryption