update to 05.Ethernet Lan Switching

04. Intro to the CLI.md

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+---
+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
+```
+
+