2 - Network Components

• Computer Science
• Upper Secondary (Key Stage 4)
• GCSE

Network Components

To understand the key components, which form a network.

• I am able to describe a Network.
• I can dentify what the key components that make up a Network are.
• I am able to describe what the key components of a Network do.  
• I am able to explain where we might need a Network.

To explain the suitability of a Network.

Session Layer

Presentation Layer

Physical Layer

Data Link Layer

Network Layer

Transport Layer

Application Layer

IP Address

An IP Address is a unique numerical label assigned to each device connected to a computer network.

32-bit addresses v 128-bit addresses

decimal v hexidecimal

 192.168.0.1 v 2001:0db8:0001:0000:0000:0ab9:C0A8:0102

20 byte header v 40 byte header

No built in security v Built in security

IPv4 vs. IPv6

Subnetting

Partitioning of an IP network into smaller subnetworks.

Subnets

An IP address always includes a subnet. A subnet divides an IP address into two parts:

• network part
• host part

Subnet structure

• A subnet has the same structure as an IP address, namely four blocks of 8 bits. 
• The subnet indicates which IP addresses can be found within a network.

Structure of IP address

The subnet therefore divides an IP address into two parts, a network part and a host part.

IP address: 192.168.1.25

Subnet: 255.255.255.0

192.168.1 = network part

25 = host part

Parts of IPv4

IP address: 192.168.10.125

Subnet: 255.255.255.0

192.168.10 = network part

125 = host part

IP address: 192.168.10.125

Subnet: 255.255.255.0

192.168.10 = network part

125 = host part

Discuss with your partner these 2 parts.

You have the IP address 10.25.68.125 on a Class B network with the subnet 255.255.0.0.

What is the network part of the IP address?

1. 10.
2. 10.25
3. 10.25.68
4. 10.25.68.125

You have the IP address 10.25.68.125 on a Class C network with the subnet 255.255.255.0.

What is the network part of the IP address?

1. 10.
2. 10.25
3. 10.25.68
4. 10.25.68.125

You have the IP address 172.16.25.233 on a Class C network with the subnet 255.255.255.0.

What is the host part of the IP address?

1. 233
2. 25.233
3. 16.25.233
4. 172.16.25.233

You have the IP address 192.168.15.1 on a Class B network with the subnet 255.255.0.0.

What is the host part of the IP address?

1. 1
2. 15.1
3. 168.15.1
4. 192.168.15.1

Private IP Address

A private IP address is an IP address that is not routable over the public internet and is reserved for use within a private network. 

Public IP Address

A public IP address is an IP address that is routable over the public internet and is globally unique.

DNS

DHCP

Gateway

Domain Controller

A server that has a table of Domain Name to IP

Server issues IP addresses

Device that allows you to be connected to the outside world

Device that gives you access to log on and gives you access to 

network Resources

Network Components

Transmission Media

Router

Gateway

Switch

Wireless Access Point

Firewalls

Network Media - Communication Transmission

Network cables

• To connect together different devices, you need cables.
  

• They have plastic plugs that connect into sockets on devices.
  

• The cable is made up of a number of copper wires.
  

Router

• A router is used when we want to connect 2 networks together across distances. 

• A router forwards messages from one network to another. It acts as a gateway.

• A common job of a router is to join a home network to the internet via an internet service provider (ISP).

 

Gateway

Switch 

Wireless Access Point (WAP) 

Which of the following is not a protocol for a web address

1. Must start with ‘http://’ followed by ‘www’.
2. You must include dots to seperate.
3. The address mus t be unique.
4. An ‘@’ symbol must be used.

Switch

Wireless Access Point

A router acts as a gateway to the internet

1. True
2. False

What material is used to make the wires for network cables

1. Gold
2. Iron
3. Copper
4. Brass

Which waves do wireless networks use to send data?

1. Infrared
2. Gamma
3. Radio
4. X-ray

Which do you think has the highest bandwidth?

1. 4G
2. 3G
3. Bluetooth
4. 5G

What is the internet?

1. A set of rules to allow communication
2. A worldwide network of computers
3. A gateway on a network
4. A single network

Who owns the internet

1. The government
2. No one
3. Vinton Gray
4. Google

Which of the following best describes the structure of an IP address?

1. 4 numbers between 0 and 100, separated by dots
2. 4 numbers between 0 and 255, separated by dots
3. 3 numbers between 0 and 255, separated by dots
4. 4 numbers between 0 and 255, separated by dashes

Do you think your home 'network' would be different from the school 'network'?

Yes

No

Maybe

I don't know

The 'School Network'

What are the main differences?

Network Switches: A school network often has multiple network switches, which allow multiple devices to connect to the network and communicate with each other.

Server Hardware: A school network may have one or more servers, which are used to run network applications such as email, student information systems, and learning management systems.

Network Security Appliances: School networks typically have more advanced network security appliances than a home network, such as firewalls, intrusion detection and prevention systems, and content filters.

What is a Router?

1. A networking device that forwards data packets.
2. A device used to cut wood.
3. A musical instrument.
4. A kitchen appliance for making toast.

What is the difference between a switch and a hub?

1. A switch sends data to a specific device, while a hub sends data to all connected devices.
2. A switch and a hub are the same thing.
3. A switch is used for gaming, while a hub is used for streaming.
4. A switch is used for cooking, while a hub is used for storage.

Activity

Using Cisco Packet Tracer

Build a network with:

- 2 PCs

- 1 switch

- 1 DHCP server

Have PCs obtain IP addresses via DHCP

And then do the packet tracer activities in the shared file

Subnet: 255.255.255.240

Binair: 11111111.11111111.11111111.11110000

Aantal IP adressen: 15