Command Line Commands

Question 1

show running-configuration

Answer 1

Configuration that is currently running on the device’s memory.

Question 2

show startup-configuration

Answer 2

Configuration that will be loaded on restart.

Question 3

show version

Answer 3

The following version information:

Hardware configuration
Running IOS version
ROM bootstrap version
RAM and processor information

Question 4

show flash

Answer 4

The following flash information:

• Size of the configuration files
• Available flash memory
• Information for all IOS image files stored
  on the device

Question 5

show clock

Answer 5

The current time and date of the device.

Question 6

show history

Answer 6

Commands in the command history list.

Question 7

show interface

Answer 7

Information about a router’s interface including:

• Interface status (whether it’s up or down)
• Utilization
• Protocol status on the interface
• Errors
• Maximum transmission unit (MTU)

Question 8

show ip interface

Answer 8

Information about the configuration of the IP protocols on each interface, including:

• IP address
• Layer 2 status
• Layer 3 status

Question 9

show ip route

Answer 9

The following routing table information:

• Networks the router can reach
• Metric
• Route to each network

Question 10

Router# copy run start

Answer 10

Saves the contents of the running-config file to NVRAM.

Question 11

Router# copy start run

Answer 11

Copies the startup-config file into RAM.

Question 12

Router# copy run tftp

Answer 12

Saves the contents of the running-config file to a TFTP server.

Question 13

Router# copy start tftp

Answer 13

Saves the contents of the startup-config file to a TFTP server.

Question 14

Router# copy tftp start

Answer 14

Copies a configuration file from the TFTP server into NVRAM.

Question 15

Router# copy tftp run

Answer 15

Copies a configuration file from the TFTP server into RAM.

Question 16

Router# copy flash tftp

Answer 16

Copies the IOS image to the TFTP server. When using this command, you will be prompted for the destination file name and address.

Question 17

Router# erase flash

Answer 17

Deletes the contents of Flash memory (deletes the IOS image).

Question 18

Router# erase start

Answer 18

Erases the contents of the startup-config file.

Question 19

Router# erase nvram

Answer 19

Deletes the contents of NVRAM (which also erases startup-config).

Question 20

?

Answer 20

Displays a list of commands available in the current mode

Question 21

Command ?

Answer 21

Displays keywords and arguments for the specified command

Question 22

Partial_Command + Tab

Answer 22

Inserts the full command from a partial command

Question 23

Help Prompts

Answer 23

WORD - Type a one-word response
LINE - Type a multiple-word response
[0-4567] - Type a number within the provided range
[0-FFFFFF] - Type a number within the range in brackets
[cr]> - The command is complete as typed
A.B.C.D - Type an IP address

Question 24

Command History

Answer 24

The command history feature saves you time by eliminating the need to retype a command you recently entered. Command history temporarily stores a list of commands you have used. Commands stored in command history can be recalled by the user. By default, the system stores up to 10 command lines, but this number can be increased or decreased as needed. The following table describes how to use command history.

Question 25

Ctrl + P or Up arrow

Answer 25

Shows the previous command

Question 26

Ctrl + N or Down arrow

Answer 26

Shows the next command

Question 27

terminal history

Answer 27

Turns command history on

Question 28

terminal no history

Answer 28

Turns command history off

Question 29

terminal history size <0-256>

Answer 29

Sets the number of lines in the history buffer

Question 30

show history

Answer 30

Shows all the commands in the history buffer

Question 31

Command Editing Facts

Answer 31

The IOS command line interface (CLI) provides shortcuts that make keyboard input easier.

Question 32

Tab

Answer 32

Completes a command name entry that has been partially entered.

Question 33

Ctrl + A

Answer 33

Moves to the beginning of the line.

Question 34

Ctrl + E

Answer 34

Moves to the end of a line.

Question 35

Ctrl + B or Left Arrow

Answer 35

Goes forward one character.

Question 36

Esc, B

Answer 36

Goes back one word. Note that you must release the Esc key before pressing B.

Question 37

Esc, F

Answer 37

Moves forward one word. Note that you must release the Esc key before pressing F.

Question 38

Ctrl + Z

Answer 38

Quits a configuration mode.

Question 39

terminal editing

Answer 39

Turns advanced editing on.

Question 40

terminal no editing

Answer 40

Turns advanced editing off.

Question 41

Backspace

Answer 41

Removes the character to the left of the cursor.

Question 42

Ctrl + D

Answer 42

Removes the character at the cursor.

Question 43

Ctrl + K

Answer 43

Removes all characters from the cursor to the end of the command line.

Question 44

Esc, D

Answer 44

Removes all characters from the cursor to the end of the word. Note that you must release the Esc key before pressing D.

Question 45

Ctrl + U or Ctrl + K

Answer 45

Removes all characters from the cursor to the end of the command line.

Question 46

Ctrl + W

Answer 46

Removes the word to the left of the cursor.

Question 47

Router(config)# hostname [name]

Answer 47

Changes the name of the router.

Question 48

Router(config)# int serial 0/0 Router(config)# int s0/0 Router(config)# int Ethernet 0 Router(config)# int ether0 Router(config)# int FastEthernet 0/1 Router(config)# int Fa0/1 Router(config)# int Gigabit 0/1 Router(config)# int gi0/1

Answer 48

Enters the interface configuration mode for the first serial interface. You can use abbreviations for the interface type, such as: fa = FastEthernet gi = Gigabit s = Serial e = Ethernet

Question 49

Router(config-if)# description [description text]

Answer 49

Sets a description for a specific interface

Question 50

Router# config t Router(config)# hostname ATL1 ATL1(config)#

Answer 50

Sets the hostname of the router to ATL1

Question 51

Router(config)# int ser 0 Router(config-if)# description ATL to NYC

Answer 51

Adds the description ATL to NYC for the first serial interface on the router.

Question 52

banner and banner motd

Answer 52

Sets the message-of-the-day (MOTD) banner. The MOTD banner displays immediately after a connection is made.

Question 53

banner login

Answer 53

Sets the login banner. The login banner displays after the MOTD banner and before the login prompt.

Question 54

banner exec

Answer 54

Sets the exec banner. The exec banner displays after a successful login.

Question 55

banner incoming

Answer 55

Sets the incoming banner. The incoming banner displays for a reverse Telnet session.

Question 56

no banner type

Answer 56

Removes the specified banner.

Question 57

Router(config)# enable secret password

Answer 57

Sets the encrypted password used for privileged mode access. The enable secret should always be used if it exists.

Question 58

Router(config)# enable password password

Answer 58

Sets the unencrypted password for privileged mode access. This password is used if enable secret is not set.

Question 59

Router(config)# Line console interface

Answer 59

This global config command allows a user to enter console configuration mode. The zero identifies the console interface (usually there is only one.)

Question 60

Router(config)# Line vty vty line [0-15]

Answer 60

This global config command allows a user to enter line VTY mode.

Question 61

Router(config-line)# Login

Answer 61

VTY access can be enabled using the login command.

Question 62

Router(config-line)# no enable secret Router(config-line)# no enable password Router(config-line)# no login Router(config-line)# no password

Answer 62

Removes the password. The no login command disables password checking.

Question 63

Service-password-encryption

Answer 63

It is important to note that the startup-config and running-config files show passwords in plain text. Because of this, you should encrypt your passwords using the global configuration service password-encryption command. This command provides a basic level of encryption to all unencrypted passwords within the config file. Note that these passwords are only lightly encrypted and can be easily broken. However, they do provide some level of security from someone looking over your shoulder. Rather than relying on this encryption, make sure to use the enable secret command for better encryption.

Question 64

do show run

Answer 64

reveals passwords (does not show if passwords are encrypted)