Chapter 2: Configure a Network Operating System

The privileged EXEC mode can be identified by the prompt ending with the

# symbol.

Global configuration mode is identified by a prompt that ends with

(config)# after the device name such as Switch(config)#

The user EXEC mode is identified by the CLI prompt that ends with the

> symbol.

In the command Switch>ping 192.168.10.5, 192.168.10.5 would be an example of what?

Argument

Not predefined; a value or variable defined by the user

Arguments

Some devices, such as routers, may also support a legacy _____ port that was used to establish a CLI session remotely using a modem.

Auxiliary

Erases the character to the left of the cursor

Backspace

boldface indicates what when describing the use of commands?

Boldface text indicates commands and keywords that you enter literally as shown.

[x{y | z}] indicates what when describing the use of commands?

Braces and vertical lines within square brackets indicate a required choice within an optional element.

{x} indicates what when describing the use of commands?

Braces indicate a required element (keyword or argument)

When using a ____ the 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.

CLI or Command-line Interface

What is the network operating system used by Cisco called?

Cisco Internetwork Operating System

What are the two ways a user can interact with the shell of a OS?

Command-line interface (CLI)or a graphical user interface (GUI)

When using the CLI, the mode is identified by the what?

Command-line prompt that is unique to that mode.

The advantage of using a _____ port is that the device is accessible even if no networking services have been configured, such as when performing an initial configuration of the networking device. When performing an initial configuration, a computer running terminal emulation software is connected to the console port of the device using a special cable. Configuration commands for setting up the switch or router can be entered on the connected computer.

Console

This is a physical management port that provides out-of-band access to a Cisco device.

Console

What are the commons ways to access the CLI environment of a switch and configure the device?

Console Secure Shell (SSH) Telnet

The IOS has two forms of help available:

Context-Sensitive Help Command Syntax Check

_____ help enables you to quickly find which arguments and keywords are available to particular commands.

Context-Sensitive help

______ help enables you to quickly find which commands start with specific characters or group of characters.

Context-Sensitive help

_______ help enables you to quickly find which commands are available in each command mode.

Context-Sensitive help

Erases the character at the cursor

Ctrl-D

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

Ctrl-K

Erases all characters from the cursor back to the beginning of the command line

Ctrl-U or Ctrl-X

Erases all characters from the cursor to the end of the word

Esc D

True or False: Network devices are not typically accessed through a CLI.

False

True or False: You do not need to access Global configuration mode before other specific configuration modes?

False

Operating system on home routers is usually called what?

Firmware

Allows the user to interact with the system using an environment of graphical icons, menus, and windows. It is more user-friendly and requires less knowledge of the underlying command structure that controls the system.

GUI

Windows, OS X, Apple iOS, or Android are an example of a _____ interface.

GUI or Graphical User Interface

What are some issues with GUIs?

GUIs may not be able to provide all of the features available at the CLI. GUIs can also fail, crash, or simply not operate as specified.

To configure a router or a switch the user must enter what mode?

Global Configuration Mode or global config mode

The physical part of a computer including underlying electronics.

Hardware

Cisco routers and switches use

Hierarchal system

What does the command syntax check do if the command was entered incorrectly?

However, if the interpreter cannot understand the command being entered, it will provide feedback describing what is wrong with the command.

What does the command syntax check do if the command entered is correct?

If the interpreter understands the command, the requested action is executed, and the CLI returns to the appropriate prompt.

What does the description command do?

It typically is used to identify the purpose of an interface. for example description This is the main router This indicates the main router

What does the command syntax check verify?

It verifies that a valid command was entered by the user.

italics indicates what when describing the use of commands?

Italic text indicates arguments for which you supply values

Communicates between the hardware and software of a computer and manages how hardware resources are used to meet software requirements.

Kernel

A specific parameter defined in the operating system

Keyword

The general syntax for a command is the command followed any appropriate what?

Keywords and argumnets

What does CLI require in order for users to use it effectively?

Knowledge of the underlying structure that controls the system.

Compared to a GUI, CLI is

Less resource intensive and very stable

From global config mode, the user can enter different sub-configuration modes. Each of these modes allows the configuration of a particular part or function of the IOS device. Two common sub-configuration modes include:

Line Configuration Mode Interface Configuration Mode

Privileged EXEC Mode

Mode allows access to all commands and features. The user can use any monitoring commands and execute configuration and management commands.

User EXEC Mode

Mode allows access to only limited number of basic monitoring commands It is often referred to as "view-only"" mode

All end devices and network devices require an ______

Operating System or OS

What does out-of-band mean?

Out-of-band access refers to a access via a dedicated management channel that is used for device maintenance purposes only.

To execute configuration commands, a network administrator must access ______ mode.

Privileged EXEC Mode

There are a number of excellent terminal emulation programs available for connecting to a networking device either by a serial connection over a console port or by a SSH/Telnet connection. Some of these include:

PuTTY Tera Term SecureCRT OS X Terminal

_____ is the recommended method for remote management because it provides a secure connection. _____ provides encrypted password authentication and transport of session data. This keeps the user ID, password, and the details of the management session private. Most versions of Cisco IOS include an ____ server and an ____ client that can be used to establish SSH sessions with other devices.

SSH or Secure Shell

Is a method for remotely establishing a secure CLI connection through a victual interface, over a network. Unlike a console connection, ___ connections require active networking services on the device including an active interface configured with an address.

Secure Shell (SSH)

The user interface that allows users to request specific tasks from the computer. These requests can be made either through the CLI or GUI interfaces.

Shell

[x] indicates what when describing the use of commands?

Square brackets indicate an optional element (keyword or argument)

Default Device prompts for Privileged Exec Mode

Switch# Router#

Example of line command and exiting it back to global configuration mode

Switch(config)# line console 0 Switch(config-line)# exit Switch(config)#

You can also move directly form sub-configuration mode to another. Notice how after selection an interface, the command prompt changes form (config-line)# to (config-if)#

Switch(config)#line console 0 Switch(config-line)# interface FastEthernet 0/1 Switch(config-if)#

The default prompt for interface configuration mode is

Switch(config-if)#

For example, the default prompt for line configuration mode is

Switch(config-line)#

Example of moving from any sub-configuration mod to the privileged EXEC mode

Switch(config-line)#end Switch#

In the command Switch>show ip protocols, what is the prompt in the command?

Switch>

Default Device prompts for User Exec Mode

Switch> Router>

Completes a partial command name entry

Tab

Best practice dictated to use SSH instead of ___ for remote management CLI connections. CISCO IOS includes a ___ server and _____ client that ca be used to establish ____ sessions with other devices.

Telnet

Is an insecure method of remotely establishing a CLI session through a virtual interface, over a network. Unlike SSH, ______ does not provide a securely encrypted connection. User authentication, passwords, and commands are sent over the network in plain text.

Telnet

ping ip-address, which is the command and which is the argument or keyword?

The command is ping and the user-defined argument is the ip-address of the destination device. For example, ping 10.10.10.5.

traceroute ip-address, which is the command and which is the argument or keyword?

The command is traceroute and the user-defined argument is the ip-address of the destination device. For example, traceroute 192.168.254.254.

By default, every prompt begins with what?

The device name

The portion of the OS that interacts directly with computer hardware is known as what?

The kernel

Following the name, the remainder of the prompt indicates

The mode

The portion of the operating system that interfaces with applications and the user is known as the what?

The shell

Cisco networking devices run particular versions of the Cisco IOS. The IOS version is dependent on

The type of device being used and the required features.

True or False: A Cisco IOS switch can be implemented with no configuration and still switch data between connected devices.

True

A CLI-based network operating system like the Cisco IOS on a switch or router enables a network technician to:

Use a keyboard to run CLI-based network programs Use a keyboard to 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:

Use a mouse to make selections and run programs Enter text and text-based commands View output on a monitor

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

This mode has limited capabilities but is useful for basic operations. It allows only a limited number of basic monitoring commands but does not allow the execution of any commands that might change the configuration of the device. The user EXEC mode is identified by the CLI prompt that ends with the > symbol.

User EXEC Mode

As a security feature, the Cisco IOS software separates management access into the following two command modes:

User EXEC Mode Privileged EXEC Mode

How does the command syntax check verify a command?

When a command is entered, the command line interpreter evaluates the command from left to right.

How do you access context-sensitive help?

You enter a question mark, ?, at the CLI

In the command Switch>ping 192.168.10.5, ping is an example of what in the command structure?

command

To move in and out of global configuration mode, use the _______ privileged EXEC mode command.

configure terminal or conf t

The syntax for using the description command is

description string or arguments (is provided by the user) for example description This is the main router

Use the ________ privileged EXEC mode command to return to user EXEC mode.

disable

To move from user EXEC mode to privileged EXEC mode, use the

enable command or en

Privileged EXEC mode is sometimes called

enable mode

To move from any sub-configuration mode to the privileged EXEC mode, enter the ______ command or enter the key combination ____

end or Ctrl+Z

To exit a sub-configuration mode and return to global configuration mode, use the _____ command.

exit

To move from any sub-configuration mode of the global configuration mode to the mode one step above it in the hierarchy of modes, enter the ______ command

exit

To return to the privileged EXEC mode, enter the _____ global config mode command.

exit

In the command Switch>show ip protocols, what is an example of a keyword or argument?

ip protocols

In the command Switch>show ip protocols, ip protocols would be and example of what?

keyword

There are many different sub-configuration modes. For example, to enter line sub-configuration mode, you use the _____ command followed by the management line type and number you wish to access.

line

Similar to a console connection, the AUX port is _______ and does not require networking services to be configured or available.

out of band

Higher configuration modes, like global configuration mode, can only be reached from ________

privileged EXEC mode.

In the command Switch>show ip protocols, what is an example of a command?

show

From global config mode, CLI configuration changes are made that affect the operation of the device as a ____

whole

Terminal Emulation Programs allow you to enhance you productivity by adjusting ____

window sizes, changing font sizes, and changing color schemes.