NETWORKS PART 3

Question 1

What does every device on a network have

Answer 1

Every device on a network has a Network Interface Card (NIC) - although this may be built into the motherboard

Question 2

What does every NIC have

Answer 2

Every NIC has a Media Access Control (MAC) address

Question 3

What is MAC addressing used for

Answer 3

MAC addressing is used to route frames on a local area network (LAN)

A MAC address is assigned to devices; its use within a network

MAC address are mainly used by the Ethernet protocol on LANs
LAN switches read the MAC addresses and use them to direct data to the right device

They are uniue to the device and cannot be changed

Question 4

Features of a MAC address

Answer 4

Example of MAC address: 00:0a:95:9d:68:16

Each MAC address is unique to every network interface card

Question 5

Why is IP addressing used

Answer 5

If the LAN is connected to a WAN such as The Internet then we need a different addressing method

Question 6

What is IP addressing used for

Answer 6

IP addressing is used to route packets on a wide area network (WAN):

IP addressing is used to route frames on a wide area network (WAN)

On a WAN we refer to frames as packets

Used when sending data between TCP/IP networks e.g. over the interent

Assigned either manually or automatically before the device can access the network

Question 7

How many versions of IP addressing are there

Answer 7

There are two versions of IP addresses IPv4 and IPv6 (IP version 4 and IP version 6)

Question 8

Features of IPv4 address

Answer 8

32-bits in size

Written as four numbers separated by periods (.), each number in the range 0-255

Example 69.89.31.212

Question 9

Why is IPv4 being replaced by IPv6

Answer 9

IPv4 is being replaced by IPv6 because unique static addresses are running out

Question 10

Features of IPv6 address

Answer 10

128-bits in size

Written as eight groups separated by colons ( : ), each group made up of four hex values representing 16-bits

Example: 2001:0dn8:85a3:0000:0000:8a2e:0370:7334

Question 11

What are standards

Answer 11

Standards are a set of specifications for:

Hardware

Software

Question 12

Purpose of standards

Answer 12

Standards make it possible for:

Manufactures

Producers….

…. to create products and services which are compatible with each other

Question 13

What would happen if there were no standards

Answer 13

Without standards most devices wouldn’t be able to successfully interact or communicate.

Question 14

Examples of different protocols

Answer 14

Protocol acronym - Protocol Full Name - Area/Purpose

TCP/IP (Transmission Control Protocol / Internet Protocol)
- Communicate over LANs and WANs

HTTP (Hypertext Transfer Protocol) - Web page requests
HTTPS (Hypertext Transfer Protocol Secure ) - Web page requests

FTP (File Transfer Protocol) - File transfers

POP (Post Office Protocol) - Email
IMAP (Internet Message Access Protocol) - Email
SMTP (Simple Mail Transfer Protocol) - Email

Question 15

What is a protocol

Answer 15

A protocol is a set of rules (like a language/ guidelines devices follow) that allows two devices to communicate (in some way)

Question 16

Purpose of TCP/IP protcol

Answer 16

This group of protocols are used over the internet

The Transmission Control Protocol (TCP) provides an error free transmission between two routers. (provides an error free way of transmitting data between two routers)

The Internet Protocol (IP) routes packets across a wide area network

Together they make up the TCP/IP protocol stack which is the (basic) foundation of all communication over The Internet.

(routing packets is like determining which route the packets take to get to a set destination)

Question 17

Purpose of HTTP protocol

Answer 17

Used by web browsers to access websites and communicate with web servers

It is the fundamental protocol of the World Wide Web (WWW).

When you type in a web address in a web browser and you look at the address at the top, you will often see HTTP

You can see that this is the protocol being used so that you can receive the web page in your browser

Question 18

Purpose of HTTPS protocol

Answer 18

A more secure version of HTTP (http purpose: used by web browsers to access websites and communicate with web servers) - Encrypts all information sent and recieved

Question 19

Purpose of FTP

Answer 19

Used to access, edit and more files between devices on a network e.g. to access files on a server from a client computer

Question 20

Purpose of POP

Answer 20

Used to retrieve emails from a server. The server holds the email until you download it, at which point it is deleted from the server

Question 21

Purpose of IMAP

Answer 21

Used to retrieve emails from a server. The server holds the email until you delete it - you only download a copy. Used by most web-based email clients

Question 22

Purpose of SMTP

Answer 22

Used to send emails. Also used to transfer emails between servers

Question 23

What is a layer

Answer 23

A layer is a group of protocols which have similar functions

Question 24

What is the concept of layering
PURPOSE OF LAYERING

Answer 24

The concept of layering is to divide the complex task of networking into smaller, simpler tasks that work with each other.

Question 25

Features of layering

Answer 25

The hardware and/or software for each layer has a defined responsibility

Each layer provides a service to the layer above it.

Question 26

The advantages of layering include

Answer 26

Reduces the complexity of the problem into manageable sub-problems .
It breaks network communication into manageable pieces. This helps developers concentrate on only one area of the network without having to worry about the network.

As layers are self-contained, they can be changed or developed without the other layers being affected
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It makes it easier to identify and correct any networking errors and problems

Devices can be manufactured to operates at a particular layer

Each layer is specialised to perform a particular function

Having standards for each layers forces companies to make compatible, universal hardware and software. So Products from different vendors will work together ( so that products from different manufactures will be able to communicate with each other)

The different layers can be combined in different ways as required