network fundamentals ch 2

Which functionality is provided by DHCP

automatic assignment of an IP address to each host

Which is the command to configure a banner to be displayed when connecting to a switch?

banner motd $ keepout$

Configuration files

can also be saved and archived to a text document. This sequence of steps ensures that a working copy of the configuration file is available for editing or reuse later.

kernel

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

Which access method would be most appropriate if you were in the equipment room with a new switch that needs to be configured?

console

Which access method would be most appropriate if your manager gave you a special cable and told you to use it to configure the switch?

console

IOS has two forms of help available

context-sensitive help and command syntax check.

Which two functions are provided to users by the context-sensitive help feature of the Cisco IOS CLI? (Choose two.)

displaying a list of all available commands within the current mode determining with option. keyword or arguments is available for the entered command

What is the structure of an IPv4 address called?

dotted decimal format

To what subnet does the IP address 10.1.100.50 belong if a subnet mask of 255.255.0.0 is used?

10.1.0.0

Password Guidelines

use of weak or easily guessed passwords continues to be the biggest security concern of organizations. Network devices, including home wireless routers, should always have passwords configured to limit administrative access.

A router with a valid operating system contains a configuration file stored in NVRAM. The configuration file has an enable secret password but no console password. When the router boots up, which mode will display?

user EXEC mode

which IOS mode are you in if the swith > prompt is displayed

user EXEC mode

Command syntax check

verifies that a valid command was entered by the user.

Which access method would be the most appropriate if you call your manager to tell him you cannot access your router in another city over the internet and he provides you with the information to access the router through a telephone connection?

AUX

operating system (OS)

All end devices and network devices require an

[x {y | z }]

Braces and vertical lines within square brackets indicate a required choice within an optional element. Spaces are used to clearly delineate parts of the command.

{x}

Braces indicate a required element (keyword or argument)

which two commands would return you to the privileged EXEC prompt regardless of the configuration mode you are in? (Choose two.)

CTRL+Z end

Examples of end devices include these:

Computers (work stations, laptops, file servers, web servers) Network printers VoIP phones Security cameras Smart phones Mobile handheld devices (such as wireless barcode scanners)

which IOS mode allows access to all commands and features

privileged EXEC mode

various types of media:

Distance the media can successfully carry a signal Environment in which the media is to be installed Amount of data and the speed at which it must be transmitted Cost of the media and installation

show running-config

privileged EXEC mode command is used to view the running config.

Two common subconfiguration modes include:

Line Configuration Mode Interface Configuration Mode

Privileged EXEC Mode command mode

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

User Exec Mode

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

Which memory location on a Cisco router or switch stores the startup configuration file

NVRAM

which memory location on a cisco router or switch will lose all content when the device is restarted

RAM

Secure Shell (SSH)

SSH is an in-band and recommended 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. Most versions of Cisco IOS include an SSH server and an SSH client that can be used to establish SSH sessions with other devices.

[x]

Square brackets indicate an optional element (keyword or argument).

Why would a technician enter the command copy startup-config running-config?

to copy an existing configuration into RAM

ping ip-address

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

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

Encrypt Passwords

The startup-config and running-config files display most passwords in plaintext. This is a security threat because anyone can discover the passwords if they have access to these files.

Console

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 are configured, such as performing the initial configuration. A computer running terminal emulation software and a special console cable to connect to the device are required for a console connection.

keyword

This is a specific parameter defined in the operating system (in the figure, ip protocols).

Argument

This is not predefined; it is a value or variable defined by the user (in the figure, 192.168.10.5)

running-config

This is stored in Random Access Memory (RAM). It reflects the current configuration. Modifying a running configuration affects the operation of a Cisco device immediately. RAM is volatile memory. It loses all of its content when the device is powered off or restarted.

startup-config

This is the saved configuration file that is stored in NVRAM. It contains all the commands that will be used by the device upon startup or reboot. Flash does not lose its contents when the device is powered off

User EXEC Mode

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.

Privileged EXEC Mode

To 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

CLI-based network operating system (e.g., the Cisco IOS on a switch or router) enables a network technician to do the following:

Use a keyboard to run CLI-based network programs Use a keyboard to enter text and text-based commands View output on a monitor

PC operating system enables a user to do the following:

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

key points to consider when choosing passwords:

Use passwords that are more than eight characters in length. Use a combination of upper and lowercase letters, numbers, special characters, and/or numeric sequences. Avoid using the same password for all devices. Do not use common words because they are easily guessed.

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.

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

User EXEC Mode Privileged EXEC Mode

What is the default SVI on a Cisco switch?

VLAN1

Configure Passwords

When you initially connect to a device, you are in user EXEC mode. This mode is secured using the console.

Context-sensitive help enables you to quickly find answers to these questions:

Which commands are available in each command mode? Which commands start with specific characters or group of characters? Which arguments and keywords are available to particular commands?

How is the privileged EXEC mode access secured on a switch?

enables secret class

How is an IPv4 address represented?

four decimal numbers between 0 and 255 by periods

Which IOS mode are you in if the Switch(config)# prompt is displayed?

global configuration mode

What is the command to assign the name "Sw-Floor-2" to a switch?

hostname SW-Floor-2

Telnet

is an insecure, in-band method of remotely establishing a CLI session, through a virtual interface, over a network. Unlike SSH, Telnet does not provide a secure, encrypted connection and should only be used in a lab environment. User authentication, passwords, and commands are sent over the network in plaintext. The best practice is to use SSH instead of Telnet. Cisco IOS includes both a Telnet server and Telnet client.

: Privileged EXEC mode

is sometimes called enable mode.

use of IP addresses

is the primary means of enabling devices to locate one another and establish end-to-end communication on the internet. Each end device on a network must be configured with an IP address.

Which statement is true about the running configuration file in a Cisco IOS device?

it affects the operation of the device immediately when modified

What is the function of the shell in an OS?

it interfaces between the users and the kernel

Which command enables password authentication for user EXEC mode access on a switch?

login

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?

noting 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

The following examples demonstrate conventions used to document and use IOS commands:

ping ip address traceroute ip address

Which type of access is secured on a Cisco router or switch with the enable secret command?

privileged EXEC

Which command encrypts all plaintext passwords access on a switch?

service password encryption

two system files that store the device configuration:

startup-config running-config

what How is an IPv4 address represented?

switched virtual interface

Which access method would be the most appropriate in-band access to the IOS over a network connection

telnet/SSH

italics

text indicates arguments for which you supply values

boldface

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

Which two statements are true regarding the user EXEC mode? (Choose two.)

the device prompt for this mode ends with the ">" symbol only some aspects of the router configuration can be viewed

When a hostname is configured through the Cisco CLI, which three naming conventions are part of the guidelines? (Choose three.)

the hostname should be fewer than 64 characters in length the hostname should contain no spaces the hostname should begin with a letter

hardware

the physical part of a computer including underlying electronics

shell

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

GUI such as Windows, macOS, Linux KDE, Apple iOS, or Android allows

the user to interact with the system using an environment of graphical icons, menus, and windows