---
id: 04. Intro to the CLI
aliases: []
tags:
  - 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'

```Cisco
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...

```Cisco
Router>enable
Router#
```

## ? "list command available"

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

```Cisco
Router>?
Router#?

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

## Global configuration mode

To enter configuration mode

```Cisco
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

```Cisco
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

```Cisco
Router#show running-config

Router#show startup-config
```

## Saving the configureation

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

```Cisco
//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


```Cisco
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

```Cisco
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

```Cisco
Router (config) #no service password-encryption
```