Chapter 2-Configure a Network Operating System

ipconfig

Windows command that shows the IP configuration settings on a PC

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

SSH

a protocol to establish a remote secure CLI connection over the network

GUI

a user-friendly interface that provides an interaction between a user and an OS through a graphical environment

traceroute

command to check the path that a packet takes to reach a destination

ping

command to verify connectivity between the source (the device where the command is issued) and the destination (IP address used as argument)

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

What command will prevent all unencrypted passwords from displaying in plain text in a configuration file?

(config)# service password-encryption EX: To prevent all configured passwords from appearing in plain text in configuration files, an administrator can execute the service password-encryption command. This command encrypts all configured passwords in the configuration file.

To save time, IOS commands may be partially entered and then completed by typing which key or key combination?

-Tab

argument

parameter that has to be supplied by the user to an IOS command

keyword

parameter with a predefined value to be used by an IOS command

shell

portion of operating system that interacts with applications and the user

kernel

portion of operating system that interfaces directly with computer hardware

Cisco IOS

term that represents the operating systems used by Cisco networking devices

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?

-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. EX:Changes to router and switch configurations take effect as soon as the command is entered. For this reason, it is very important that changes to live production devices are always carefully planned before being implemented. If commands are entered that render the device unstable or inaccessible, the device may have to be reloaded, resulting in network downtime.

How is SSH different from Telnet?

-SSH provides security to remote sessions by encrypting messages and using user authentication. Telnet is considered insecure and sends messages in plaintext. EX:SSH is the preferred protocol for connecting to a device operating system over the network because it is much more secure than Telnet. Both SSH and Telnet are used to connect to devices over the network, and so are both used in-band. PuTTY and Terra Term can be used to make both SSH and Telnet connections.

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. User EXEC mode limits access to some show and debug commands. It is the first level of user interface encountered when configuring a router and is intended for investigation of certain functions of the device. The User EXEC prompt is identified with the ">" symbol.

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. (Choose three.)

-VTY interface - console interface -privileged EXEC mode EX: Refer to curriculum topic: 2.2.2Access to the VTY and console interfaces can be restricted using passwords. Out-of-band management of the router can be restricted in both user EXEC and privileged EXEC modes.

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 which option, keyword, or argument is available for the entered command EX:Context-sensitive help provides the user with a list of commands and the arguments associated with those commands within the current mode of a networking device. A syntax checker provides error checks on submitted commands and the TAB key can be used for command completion if a partial command is entered.

True or False?Mobile devices do not require IP addresses to communicate on the Internet.

-false EX:All devices that communicate over data networks need unique IP addresses.

Which device acts as a gateway to allow hosts to send traffic to remote IP networks?

-local router EX: For hosts to reach remote networks, they must send traffic to a local router that can route the traffic to the correct destination network. This local router is known as the default gateway and hosts must be configured with this address in order to communicate with devices on remote networks.

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

-the hostname should contain no spaces -the hostname should be fewer than 64 characters in length -the hostname should begin with a letter EX:Refer to curriculum topic: 2.2.1A hostname can be configured with upper or lower case characters and should end with a letter or digit, not a special character. A hostname should start with a letter and no space is allowed for a hostname.

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

-to copy an existing configuration into RAM EX:Usually, changes are made to a running configuration in RAM and copied to NVRAM. However, in this case, the technician wants to copy a previously saved configuration from NVRAM into RAM in order to make changes to it.?

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?

-use DHCP to automatically assign addresses. EX: Assigning IP addresses automatically using DHCP will greatly eliminate the chance of a duplicate IP address error.