Chapter 2
Privileged EXEC Mode
+ Mode allows access to all commands and features + The user can use any monitoring commands and execute configuration and management commands
PuTTY Tera Term SecureCRT OS X Terminal
4 Terminal Emulation Programs:
Use a keyboard to run CLI-based network programs Use a keyboard to enter text and text-based commands View output on a monitor
A CLI-based network operating system like the Cisco IOS on a switch or router enables a network technician to:
SVI
A technician configures a switch with these commands: SwitchA(config)# interface vlan 1 SwitchA(config-if)# ip address 192.168.1.1 255.255.255.0 SwitchA(config-if)# no shutdown What is the technician configuring?
Ctrl-Shift-6
All-Purpose break sequence. Use to abort DNS lookups, traceroutes, pings
Use DHCP to automatically assign addresses.
An IT technician has manually configured an IP address on a laptop for a new employee. Each time the employee tries to connect to the LAN, the employee receives a duplicate IP address error message. What can the company do to prevent this situation from arising again?
Nothing must be done. Changes to the configuration on an IOS device take effect as soon as the command is typed correctly and the Enter key has been pressed.
An administrator has just changed the IP address of an interface on an IOS device. What else must be done in order to apply those changes to the device?
Prompt>command (keyword or argument) Ex: Switch>show ip protocols Ex: Switch>ping 192.168.10.5
Basic IOS Command structure
Telnet
Best practice dictates to use SSH instead of ______ for remote management CLI connections.
device name
By default, every prompt begins with the ______. The remainder of the prompt indicates the mode.
Cisco IOS
Cisco Internetwork Operating System
User Exec Mode
Mode allows access to only a limited number of basic monitoring commands It is often referred to as "view only" mode
Use a mouse to make selections and run programs Enter text and text-based commands View output on a monitor
Network operating systems are similar to a PC operating system. Through a GUI, a PC operating system enables a user to:
hierarchical structure
The Cisco IOS modes use a _____ and are quite similar for both switches and routers.
type of device being used and the required features
The IOS version is dependent on the
CLI, GUI
The ____ is less resource intensive and very stable when compared to a _____.
GUIs , CLI
____ can also fail, crash, or simply not operate as specified. For these reasons, network devices are typically accessed through a _____
Virtual Terminal (VTY) Lines
____ enable remote access to devices
GUIs , CLI
____ may not always be able to provide all of the features available at the ____
SVI
a logical interface used to remotely manage a switch over an IPv4 network
console
a physical port of a Cisco device that provides access to the device via a dedicated management channel, also known as out-of-band access
DHCP
a protocol that dynamically leases IPv4 addresses to DHCP-enabled end devices
Secure Shell (SSH)
a protocol to establish a remote secure CLI connection over the network
keyword
a specific parameter defined in the operating system parameter with a predefined value to be used by an IOS command
GUI
a user-friendly interface that provides an interaction between a user and an OS through a graphical environment
Telnet
an insecure method of remotely establishing a CLI session through a virtual interface, over a network.
Cisco Internetwork Operating System (IOS)
collection of network operating systems used by Cisco networking devices.
traceroute
command to check the path that a packet takes to reach a destination
configure terminal
command to enter Global Configuration Mode
interface vlan 1
command to enter Interface sub-configuration mode
enable
command to enter Privilege EXEC Mode
hostname
command to name a device
ping
command to verify connectivity between the source (the device where the command is issued) and the destination (IP address used as argument)
Switch(config-line)#
default prompt for line configuration mode of a switch is ______
Context-sensitive help
enables you to quickly find which commands are available in each command mode, which commands start with specific characters or group of characters, and which arguments and keywords are available to particular commands.
startup configuration
file that is stored in NVRAM and that contains the configuration that has been saved on a device to be used upon startup or reboot
running configuration
file that is stored in RAM and that contains the configuration that is being done on a device
GUI
more user-friendly and requires less knowledge of the underlying command structure that controls the system.
argument
not predefined; a value or variable defined by the user parameter that has to be supplied by the user to an IOS command
exit
o return to the privileged EXEC mode, enter the ___ global config mode command.
firmware
operating system on home routers
shell
portion of operating system that interacts with applications and the user
kernel
portion of operating system that interfaces directly with computer hardware
Command-Line Interface (CLI)
requires very little overhead to operate. However, it does require that the user have knowledge of the underlying structure that controls the system.
Cisco IOS
term that represents the operating systems used by Cisco networking devices
line, management line type, number line console 0
to enter line sub-configuration mode, you use the _____ command followed by the ____ and _____ you wish to access.
Command-Line Interface (CLI)
user interacts directly with the system in a text-based environment by entering commands on the keyboard at a command prompt. The system executes the command, often providing textual output.
Command syntax check
verifies that a valid command was entered by the user. if the interpreter cannot understand the command being entered, it will provide feedback describing what is wrong with the command.
Startup-config running-config
what 2 config files display most passwords in plaintext?
ipconfig
Windows command that shows the IP configuration settings on a PC
network operating system
A ___________ enables device hardware to function and provides an interface for users to interact.
login
Command that enables a password after it has been set with the command "password"
Tab
Completes a partial command name entry
prompt ending in #
Default Device Prompt for Privileged EXEC Mode
prompt ending in >
Default Device Prompt for User Exec Mode
Ping
Fill in the blank. In order to test end-to-end connectivity, you would use the ______ command.
(config)#
Global configuration mode is identified by a prompt that ends with _____ after the device name
start with a letter contain no spaces end with a letter or digit use only letters, digits and dashes be less than 64 characters in length
Hostnames should:
service password-encryption from the global config
How do you encrypt passwords in the configuration file?
From global config mode, Password [enter a password]
How do you put a password for console access to user EXEC mode?
banner motd # [message] #
How do you set a banner?
SSH provides security to remote sessions by encrypting messages and using user authentication. Telnet is considered insecure and sends messages in plaintext.
How is SSH different from Telnet?
1)VTY interface 2)console interface 3)privileged EXEC mode
Passwords can be used to restrict access to all or parts of the Cisco IOS. Select the modes and interfaces that can be protected with passwords.
enable
Privileged EXEC mode is sometimes called ______ mode.
Up Arrow or Ctrl-P
Recalls command in the history buffer, beginning with the most recent commands
Secure Shell (SSH)
Recommended method for remote management because it provides a secure connection.
Ctrl-R or Ctrl-I or Ctrl-L
Redisplays the system prompt and command line after a console message is received.
Console
The advantage of using a ____ port is that the device is accessible even if no networking services have been configured.
Shell
The component of the operating software that provides the user interface is called the _____
Switch(config-if)#
The default prompt for interface configuration mode of a switch is ____
web browser-based GUI.
The most common method for configuring a home router is by using a
to copy an existing configuration into RAM
Why would a technician enter the command copy startup-config running-config?
command-line interface (CLI) or a graphical user interface (GUI).
The user can interact with the shell using a ____ or _____
Terminal Emulation Programs
These programs allow you to enhance your productivity by adjusting window sizes, changing font sizes, and changing color schemes.
question mark, ?,
To access context-sensitive help, simply enter a ____ at the CLI.
Global Configuration Mode, which is commonly called global config mode.
To configure the device, the user must enter _____
Exit
To exit a sub-configuration mode and return to global configuration mode, use the ____ command.
end, CTRL+Z
To move from any sub-configuration mode to the privileged EXEC mode, enter the ____ command or enter the key combination _____.
enable
To move from user EXEC mode to privileged EXEC mode, use the ____ command.
configure terminal
To move in and out of global configuration mode, use the _____ privileged EXEC mode command.
no hostname from global config
To remove the configured hostname and return the switch to the default prompt
Tab
To save time, IOS commands may be partially entered and then completed by typing which key or key combination?
enable secret [password] from global config mode
To secure privileged EXEC access is what command?
False All devices that communicate over data networks need unique IP addresses.
True or False? Mobile devices do not require IP addresses to communicate on the Internet.
Line Configuration Mode Interface Configuration Mode
Two common sub-configuration modes include:
Secure Shell (SSH)
Unlike a console connection, ____ connections require active networking services on the device including an active interface configured with an address.
disable
Use the _____ privileged EXEC mode command to return to user EXEC mode.
Interface Configuration Mode -
Used to configure a switch port or router network interface.
Line Configuration Mode -
Used to configure console, SSH, Telnet, or AUX access.
Telnet
User authentication, passwords, and commands are sent over the network in plaintext.
show running-config from privileged EXEC made
What command verifies that passwords are now encrypted in the configuration file
(config)#service password-encryption
What command will prevent all unencrypted passwords from displaying in plain text in a configuration file?
They both set a password, but "enable secret" encrypts the password.
What is the difference between the effects of the two commands "enable secret" and "enable password"?
1)the hostname should be fewer than 64 characters in length 2)the hostname should contain no spaces 3)the hostname should begin with a letter
When a hostname is configured through the Cisco CLI, which three naming conventions are part of the guidelines?
unique device name or hostname.
When configuring a networking device, one of the first steps is configuring a
Ctrl-C
When in any configuration mode, ends the configuration mode and returns to privaleged EXEC mode. When in setup mode, aborts back to the command prompt
Ctrl-Z
When in any configuration mode, ends the configuration mode and returns to privileged EXEC mode
Local Router
Which device acts as a gateway to allow hosts to send traffic to remote IP networks?
1)displaying a list of all available commands within the current mode 2)determining which option, keyword, or argument is available for the entered command
Which two functions are provided to users by the context-sensitive help feature of the Cisco IOS CLI?
1)The device prompt for this mode ends with the ">" symbol. 2)Only some aspects of the router configuration can be viewed.
Which two statements are true regarding the user EXEC mode?