Ch2 Configure A Network Operating System - John

Question 1

network operating system.

Answer 1

A network operating system enables device hardware to function and provides an interface for users to interact.

Question 2

Cisco Internetwork Operating System (IOS)

Answer 2

is a generic term for the collection of network operating systems used by Cisco networking devices. Cisco IOS is used for most Cisco devices, regardless of the type or size.

Question 3

Operating System

Answer 3

All end devices and network devices require an operating system (OS).

Question 4

kernel.

Answer 4

the portion of the OS that interacts directly with computer hardware is known as the kernel.

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

Question 5

shell

Answer 5

The portion that interfaces with applications and the user is known as the shell.

The user can interact with the shell using a command-line interface (CLI) or a graphical user interface (GUI).

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

Question 6

command-line interface (CLI)

Answer 6

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. The CLI requires very little overhead to operate. However, it does require that the user have knowledge of the underlying structure that controls the system.

Question 7

A GUI interface

Answer 7

such as Windows, OS X, Apple iOS, or Android allows the user to interact with the system using an environment of graphical icons, menus, and windows

However, GUIs may not always be able to provide all of the features available at the CLI. GUIs can also fail, crash, or simply not operate as specified. For these reasons, network devices are typically accessed through a CLI. The CLI is less resource intensive and very stable when compared to a GUI.

Question 8

Hardware

Answer 8

The physical part of a computer including underlying electronics.

Question 9

Purpose of OS

Answer 9

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

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. While all devices come with a default IOS and feature set, it is possible to upgrade the IOS version or feature set to obtain additional capabilities.

Question 10

Access Methods

Answer 10

A Cisco IOS switch can be implemented with no configuration and still switch data between connected devices. By connecting two PCs to a switch, those PCs will instantly have connectivity with one another.

Even though a Cisco switch will function immediately, configuring initial settings are a recommended best practice. There are several ways to access the CLI environment and configure the device.

Question 11

The most common methods are:

Answer 11

Console
Secure Shell(SSH)
Telnet

Question 12

Console

Answer 12

This is a physical management port that provides out-of-band access to a Cisco device. Out-of-band access refers to access via a dedicated management channel that is used for device maintenance purposes only.

The advantage of using a console 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.

Question 13

Secure Shell (SSH)

Answer 13

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

is the recommended method for remote management because it provides a secure connection SSH provides encrypted passwords 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 SSH server and an SSH client that can be used to establish SSH sessions with other devices.

Question 14

Telnet

Answer 14

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

Best practice dictates to uses SSH instead of telnet for remote management CLI connections. Cisco IOS includes a Telnet server and a Telnet client that can be used to establish Telnet sessions with other devices.

Question 15

auxiliary port

Answer 15

Some devices, such as routers, may also support a legacy auxiliary port that was used to establish a CLI session remotely using a modem. Similar to a console connection, the AUX port is out-of-band and does not require networking services to be configured or available.

Question 16

Cisco IOS Modes of Operation

Answer 16

To initially configure a Cisco device, a console connection must be established. Once consoled in, the network technician will have to navigate through various command modes of the IOS CLI. The Cisco IOS modes use a hierarchical structure and are quite similar for both switches and routers.

Question 17

To simulate the initial configuration of a Cisco switch, you first need the proper cable.

Answer 17

console cable. Then on the desktop PC, choose the RS 232 serial port, click on it, then drag over to the 2960 switch, click on the switch, and then choose the console port. I now have a connection from the desktop PC to the 2960 series switch using a rollover, or console cable.

Question 18

terminal emulation program

Answer 18

Once you have the serial cable running from your desktop PC to the switch console port, you’l l need a terminal emulation program for the initial configuration of the Cisco switch. To do this, you click on the PC, click on the desktop tab. And these are your desktop applications. The terminal emulation program says “terminal.” If you click on it, you’ll see the terminal configurations that you would need if you were using a real terminal emulation program, like Putty or Tera Term.

You can see the bits per second, data bits, parity, stop bits, and flow control have already been configured for you. All you need to do is click “okay.” Now I have a terminal connection to the switch.

Question 19

User EXEC Mode

Answer 19

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.

Question 20

Privileged EXEC Mode

Answer 20

o execute configuration commands, a network administrator must access privileged EXEC mode. Higher configuration modes, like global configuration mode, can only be reached from privileged EXEC mode. The privileged EXEC mode can be identified by the prompt ending with the # symbol. Enable press enter

Question 21

Global Configuration Mode

Answer 21

To configure the device, the user must enter Global Configuration Mode, which is commonly called global config mode.
From global config mode, CLI configuration changes are made that affect the operation of the device as a whole. Global configuration mode is identified by a prompt that ends with (config)# after the device name, such as Switch(config)#. Enable (if not in privileged exec mode) then configure terminal

Global configuration mode is accessed before other specific configuration modes. 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: configure terminal

Question 22

Two common sub-configuration modes include:

Answer 22

Line Configuration Mode

Interface Configuration Mode

Question 23

Line Configuration Mode

Answer 23

Used to configure console, SSH, Telnet, or AUX access.

the default prompt for line configuration mode is Switch(config-line)#

Question 24

Interface Configuration Mode

Answer 24

Used to configure a switch port or router network interface.

the default prompt for interface configuration mode is Switch(config-if)#.

Question 25

To move from user EXEC mode to privileged EXEC mode

Answer 25

use the enable command. Use the disable privileged EXEC mode command to return to user EXEC mode.

Question 26

To move in and out of global configuration mode

Answer 26

use the configure terminal privileged EXEC mode command. To return to the privileged EXEC mode, enter the exit global config mode command.

Question 27

sub-configuration modes.

Answer 27

to enter line sub-configuration mode, you use the line command followed by the management line type and number you wish to access. To exit a sub-configuration mode and return to global configuration mode, use the exit command. Notice the changes in the command prompt.

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

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 exit command.

To move from any sub-configuration mode to the privileged EXEC mode, enter the end command or enter the key combination Ctrl+Z.

Question 28

sub-configuration modes. 2

Answer 28

You can also move directly from one sub-configuration mode to another. Notice how after selecting an interface, the command prompt changes from (config-line)# to (config-if)#.
Switch(config-line)# interface FastEthernet 0/1
Switch(config-if)#

From global configuration mode you can enter sub configuration modes
line console 0 to get to the management interface for the console port
if you type exit from a sub configuration mode you enter global configuration mode
line vty 0 15 for the virtual terminal management interface
you can move directly from one sub configuration mode to another if you type interface vlan 1 from within line vty configuration mode it will take you directly to interface configuration mode

Question 29

Basic IOS Command Structure

Answer 29

A Cisco IOS device supports many commands. Each IOS command has a specific format or syntax and can only be executed in the appropriate mode. The general syntax for a command is the command followed by any appropriate keywords and arguments.

After entering each complete command, including any keywords and arguments, press the Enter key to submit the command to the command interpreter.

The following examples demonstrate conventions used to document and use IOS commands.
• ping ip-address - The command is pingand the user-defined argument is the ip-address of the destination device. For example, ping 10.10.10.5.
• traceroute ip-address - The command is traceroute and the user-defined argument is the ip-address of the destination device. For example, traceroute 192.168.254.254.

Prompt Command Space Keyword or Argument

Question 30

Keyword

Answer 30

Keyword - a specific parameter defined in the operating system (in the figure, ip protocols)

Question 31

Argument

Answer 31

Argument - not predefined; a value or variable defined by the user (in the figure, 192.168.10.5)