Introduction to Networking.pptx

Class 1: Networking Introduction
 Networking Terminologies
 What to Cover.
 What is Computer network and networking?
 So What is this data?
 Types of Networking (LAN,MAN,WAN)
 Network Topology(Bus, Ring, Star, Mesh, hybrid)
 Types of Networks (Wired, Wireless)
 Network Duplex/ Transmission Modes
 Client and Server Explained

 What is Computer network and networking?
- Computer network- two or more networking devices are linked to share data.
- Computer networking- A process where connected devices can share data.
- Carried out by networking devices like computers, routers, switches, etc.
- Set of networking protocols guides the process of networking.
- Protocols are rules e.g. HTTP,TELNET,SNMP,TCP,UDP,IP etc.
- The protocols are defined in the OSI layer.

 So What is this data?
- Data is information stored or processed by a computer.
- Information is organized data.
- Data can be inform of video, audio, numbers, alphabets, characters,
pictures etc.
- Computer stores data in binary format.
- Data entering= input
- Data working= process
- Data showing results= output

 Types of Networking---1
 LAN,MAN & WAN
1. Local Area Network (LAN)
- Here the network coverage is small; smaller geographical area.
- Like within school, college, hospitals etc.

2. Metropolitan Area Network (MAN)
- Here the network coverage is average, larger than LAN but smaller than WAN-
average geographical area.
- Connects two or more LANs
- Like a company to its branch, college to its branch, school to another school etc.
- Coverage like at least 20 minutes walk.

3. Wide Area Network (WAN)
- Here the network coverage is very large, larger geographical area.
- Like city to city, country to country, continent to continent etc.
- Coverage like Africa to Asia.

 Network Topology--2
- This is the design/architecture of a network- how network elements are
arranged or connected.
- For example Bus, Ring, Star, Mesh and Hybrid topologies;
1. Bus Topology
- Consists of a main cable line (backbone source) and devices are connecting
using drop lines to the main line.
- Advantages; Easy to install, less cabling required etc. add more
- Disadvantages; Difficult to detect fault, not scalable etc. add more

2. Ring Topology
- Each device is connected with two cables on both sides in a dedicated point to point
links forming a ring.
- Advantages; Easy to install, easy to manage etc. add more
- Disadvantages; a link failure can fail the whole network, loops in network etc. add
more

3. Star Topology
- Each device is connected to a central device like hubs but no direct communication
between devices.
- Advantages; less expensive, easy to install, easy to detect faults, less expensive etc.
- Disadvantages; hub failure can fail the whole network, network performance is based
on hub etc. add more

4. Mesh Topology
 which into a brief description includes all nodes cooperating to distribute data
amongst each other. Devices have direct communication.
 A need to make the network to have redundancy and be scalable. Under this,
whenever a link gets down, the communication will still carry on since there are
redundant links. add more
 Disadvantages; installation and configuration is complicated, high cabling cost,
high maintenance cost etc. add more

5. Hybrid Topology
 Consists of two or more network topologies e.g. Star, bus and ring
 Advantages; flexible, reliable, scalable, redundancy, effective. add more
 Disadvantages; installation and configuration is complicated, high cabling cost,
high maintenance cost etc. add more

 Types of Networks---3
1. Wired Network
- Devices are connected to the network using cables.
- Devices are tethered to a router. E.g. Using ethernet cables
- More secure than wireless.
2. Wireless Network
- Devices are connected to the network through waves.
- Devices are Not tethered to a router. E.g. Connecting to WIFI
- Not secure as wired.

 Network Duplex/ Transmission Modes--3
- the way in which data is transmitted from one device to another device.
- Simplex mode- the communication is unidirectional, i.e., the data flow in one
direction.
- Half-duplex- direction can be reversed, i.e., the station can transmit and receive the
data as well.
- Full duplex mode- the communication is bi-directional, i.e., the data flow in both the
directions.
- check advantages and disadvantages

 Client and Server Explained--1
 Client is like a computer or a device asking for a request or information from
a server. Just a normal device.
 Server is a computer or a device giving response to information requested by
client. With high hardware functionality.

Class 2: Networking Layers
 What to Cover.
 OSI Model Introduction
 OSI Layers
 OSI Data Types and Protocols
 TCP/IP Model

 OSI Model--4
1. What is OSI?
 Full form is Open Systems Interconnection.
 Created in 1984 by International Organization of Standardization (ISO).
 It is a method/concept to show how data moves over the internet.
 Helps to understand how network works, at every layer.
 Makes network troubleshooting becomes easier,
 Different networking products can work together, Cisco and Huawei devices.
 It has seven layers.
 Data pass through the seven layers during communication.
 7 layers (Please Do Not Throw Sausage Pizza Away)

 OSI Layers
 It has seven layers.
 Physical, Data link, network, Transport, Session, Presentation and Application.
 Remember as (Please Do Not Throw Sausage Pizza Away)
 We will start with upper layers going down.
1. Application Layer
 Provides interface between the user and the internet.
 When a user wants to access internet, they use applications such as chrome, Mozilla
Firefox, Gmail, Facebook, twitter etc.
 The layer provides services like sending mails, transferring files, web browsing, working
of social media, video chatting, etc.

2. Presentation Layer
 Carries out the following tasks;
i. Encoding and Decoding
- Encoding transforms the human-readable texts into computer-readable binary
format. E.g. “Hi Dan ” into 0010011101
- Decoding will therefore change this binary format into human-readable texts,
now; 0010011101 into “Hi Dan”
ii. Encryption and Decryption
- Encryption uses encryption key algorithms to change users passwords into
formats that cannot be understood. E.g. Dan@2021 into s3#ff92!!42gdL
- Decryption uses decryption key algorithms to change the encrypted password
back to understandable format. E.g. s3#ff92!!42gdL into Dan@2021
iii. Compression and Decompression
- Compression happens on the sender side to reduce the size of data while sending
e.g. 2gb to1gb
- Decompression happens on the receiver side to regain the original data size sent
e.g. 1gb to 2gb

3. Session Layer
 The layer creates a logical or virtual path between the source and destination.
i. Start the Session
- First the layer creates the logical path between the sender and receiver.
- Then it initiates the sending and receiving of data.
ii. Manage the Session
- Takes care or monitor the logical path created during data communication. Protects
the logical path.
iii. End the Session
- When the sending and receiving is finished, it closes the logical path.

4. Transport Layer
i. Segmentation and Reassembling
- Segmentation happens on the sender side to break the original big data into
segments/small pieces before sending. Data is sent as segments. E.g. “ Bring it
Dan” is sent as segments ‘Bring’ ‘it’ ‘Dan’
- Reassembling happens on the receiver side to collect the data pieces/segments
together to form the original data. The individual segments of ‘Bring’ ‘it’ ‘Dan’ is
put back to “ Bring it Dan”.
ii. Flow Control
- Manages the flow of data speed while sending and receiving data. Ensures that the
transfer speed of both sending and receiving devices is matching.
iii. Error Control
- In case there is data loss during the transfer process, the sender resends the data.


5. Network Layer
 Carried out by routers or layer-three switches.
i. Routing
- Uses a router to connect one network to another network. Connecting different
networks.
ii. Assigning IP address
- Assigns source IP and destination IP addresses to data being transfered.
iii. Select Best Path
- When there is multiple paths to the destination, the router will choose the best
path to send data.

6. Data Link Layer
 Carried out by layer-two switches.
i. Framing
- Inserts header (at the start) and trailer (at the end) into the data. These are
information that helps the data to reach safely to destination.
ii. Adding and Deleting MAC Addresses
- Adds the source MAC and destination MAC addresses to data while sending.
- Once the data is received, it removes these addresses.
iii. Flow Control
- Manages the flow of data speed while sending and receiving data. Ensures that
the transfer speed of both sending and receiving devices is matching.
iv. Error Control
- In case there is data loss during the transfer process, the sender resends the
data.

7. Physical Layer
 Interacting with the hardware devices and physical components
 Hardware components are like router, switches, hub etc.
 Physical components are like cables. Ports, connectors etc.
 Converts the data into various forms as shown below;

 OSI Data Types and Protocols
NO Layer Devices Protocols Data Types
1 Physical Hub, modem, cables,
network cards,
connectors etc.
Bluetooth, DSL,
Ethernet etc.
Bits
2 Data Link Bridge
Switch
ARP, ATM, FDDI,
Frame Relay,
Frames
3 Network Router
Layer-three switch
ICMP, IGMP,
IPv4,IPv6, IPsec
Packets
4 Transport
Software layers
We use applications.
TCP
UDP
Segments
5 Session NetBIOS, PAP,
NFS
Data
6 Presentation JPEG, MIDI, GIFF,
TIFF
Data
7 Application HTTP, SNMP,
Telnet, DNS
Data

 TCP/IP Model--5
1. What is TCP/IP Model
 This is a method that shows how data moves over the internet, just like
OSI.
 Developed in 1978.
 Has only four layers.

2. Comparison with OSI Model
 OSI has 7 layers while TCP/IP has 4 layers.
 The TCP/IP layers function as all the OSI 7 layers.
 Below diagram shows corresponding layers implementing the functionalities
discussed under OSI layers.

Class 3: Networking Devices
 What to Cover.
 Hub
 Switch
 Router
 Firewall
 Access Points
 Wireless LAN Controllers

1. Hub
 A networking device that operates at the physical layer of OSI model.
 Connects devices together to share data.
 It is old technology not commonly used.
 Disadvantage- Consumes a lot of bandwidth due to broadcasting (not intelligent).
How It Works- When hub receives data from one device, the data is send to all (broadcast)
other devices connected to it.
Symbol

2. Switch
- A networking device that operates at the data link layer of OSI model.
- Connects devices together to share data.
- Uses mac-address to send and receive data.
- Sends data for only specific devices, new technology, conserves bandwidth.
How It Works- Switch has a memory called Content Addressable Memory (CAM) table or MAC-
Address table. The table stores the device mac-address corresponding to the switchport
numbers it is connected. When data is sent from one device to another, upon reaching the
CAM table the switch checks destination mac-address of the data and forwards the data to the
port number that corresponds the destination mac-address
 Symbol

3. Router
- A networking device that operates at the network layer of OSI model.
- Connects multiple or different networks.
- Performs packet directing functions in the network.
- Uses IP addresses to send and receive data.
- Assigns IP addresses to devices.
- Chooses best path for routing.
 Symbol

4. Layer three Switch
- A networking device that operates both at the data link and network layers of OSI model.
- Works both as a switch and router.
- Supports both switching and routing technologies.
- Works with same and different networks.
- Also called multilayered switch.
 Symbol

5. Firewall
- Can be a hardware or software that provides security to the network.
- Filters (Allows or deny) the traffic coming in or going out of the network.
- Protect against malware.
- Stops hackers to some extent.
 Types of Firewall
 Packet filtering- also called Access Control List;
- If packet match, it’s allowed. If packet don’t match, it is blocked.
- Checks source and destination IP plus source and destination ports .
- Cannot check payload (data inside the packet)
 Proxy- also called application firewall;
- It’s a software that you download and install e.g. FortiGate, Norton, Avast Endpoit protection, etc.
- Checks source and destination IP plus source and destination ports .
- Checks payload (data inside the packet).
 Hybrid
- Combines the functionalities of both packet filtering and proxy firewalls
- The best of all.

6. Access Points (AP, WAP)
- This is a networking device that creates WIFI or wireless network.
- Also known as wireless access points.
- They enable users to connect through the internet.
- The signal is stronger when you are near the device but weaker as you move further
 Symbol

7. Wireless LAN Controller (WLC)
- Also called Wireless Controller
- This is a networking device that controls many access points in a network.
- All the access points are connected to the WLC.
- Mostly used where there are many access points.
 Symbol

Class 4: Hierarchical Network Design &
Network Cables
 What to Cover.
 Part1
 What is Hierarchical Network Design?
 What are the Advantages Hierarchical Network Design?
 What are the layers of Hierarchical Network Design?
 Comparisons between these Layers
 Part2
 Networking Cable Types

 What is Hierarchical Network Design?
- This a strategy or a concept of dividing the large enterprise network into manageable parts called layers.
- These layers are access, distribution and core layers.
 Advantages
- There is redundancy in the network.
- Better Network performance.
- Easy management and troubleshooting.

1. Hierarchical Network Layers
- There are three layers namely; access, distribution and core layers.
a. Access Layer
- This is where end devices are connecting to the network.
- Layer-2 switch provides connection.
- The switches at the access layer of the hierarchical network design and infrastructure are used to provide
network access the end devices in a LAN environment.
- These switches are responsible for providing network connectivity between the servers and workstations.
- The switches are able to implement several switching technologies such as VLANs, port security, etc.

b. Distribution Layer
- Mostly used devices are layer-three switches (Multilayered switches)
- These devices operate at the distribution layer of the hierarchical network design and infrastructure to
connect the core layer and access layer devices for communication.
- The devices are responsible for aggregating the traffic from access layer switches then send to the core
layer devices for routing.
- Also, they provide functionalities of segmenting workgroups or users and isolating any possible network
problems.

c. Core Layer
- Backbone layer of the network.
- Mostly used devices are routers and layer-three switches (Multilayered switches)
- These devices act as the backbone of the network and are of high-speed to forward packets as fast as
possible.
- These networking devices, provide functionalities of aggregating traffic from the distribution layer and are
able to transfer a large amount of traffic quickly.

 Comparisons between these Layers
- The following table summarizes it all

 Part 2: Types of Networking Cables
- These are wires used to transfer data in a network.
- Mostly used are Category (CAT) cables, fiber optic cable and coaxial cable.
a. Category (CAT) cables
- uses electrical signal to send data (data-binary-electric signal)
- Contain 8 wires covered with a plastic.
- You can use connectors like RJ45 or RJ11 to connect.
- Several versions; cat3, cat5, cat5e and cat6.
- Can be made into straight-through or cross-over cables
- straight-through are used to connect different devices e.g. computer to switch, switch to router etc.
- Cross-over are used to connect same devices e.g. computer to computer, switch to switch etc.
 During Crimping

b. Fiber Optic cables
- uses light to send data (data converted into binary then into light then moves through fiber optic cable)
- Transfer data very faster.
- Can be of two types single mode or multi-mode cables

c. Coaxial cables
- Its made of copper.
- Connect TV cable connection, telephone cable connection, LAN cable connection, etc.
- Faster than CAT cable but slower than Fiber optic cable

Class 5: Network Addresses
 What to Cover.
 IP Address
 IPv4 Classes + Subnet mask, Network ID and Host ID
 IPv4 and IPv6
 MAC Address
 Difference between IP and MAC address

1. Internet Protocol (IP) Address
- This a logical address that works at the network layer of OSI model to enable devices to communicate.
- There are IPV4 and IPV6 addresses.
a. IPv4 Address
- Consist of numbers and divided into four sections (octets) separated by dots.
- Each octet contains 8 bits.
- Size is 32 bits.
- IPv4 can be private or public address

2. Media Access Control (MAC) Address
- Also called physical or hardware address.
- Used to enable to communicate in the network at layer-2 or data link layer.
- Every device has a unique mac-address.
- It’s permanent and cannot be changed.
- Made up of 6 octets separated by colon, dash, or dots.
- Comprised of two parts for vendor and host assignment.

d. Comparisons between IP and MAC Addresses

Class 6: Subnetting (Classful $ Classless)
 What to Cover.
 Meaning of subnetting
 Examples question of Classless and classful subnetting

1. Subnetting
- This is the practice of dividing a network into two or more smaller networks. It increases routing
efficiency, enhances the security of the network and reduces the size of the broadcast domain.
- Advantages; good security and performance, easy managements, less broadcast domains.
- We have classful or classless subnetting.

2. Classful and Classless Subnetting
- method of splitting a classful or classless network number into two or more smaller subnets.
- The subnets will all be the same size, determined by the maximum number of hosts per
subnet. A subnet mask is used to configure the subnets
- We use IP address and subnet mask to do subnetting.
- Each subnet has its own block size for subnetting as shown below;

3. Examples Classful Subnetting
a. Given network 192.168.10.0 and subnet mask of 255.255.255.0.
- Find network ID, first and last valid host ID, broadcast ID.
 Network= 192.168.10.0
 subnet mask of 255.255.255.0
 Considering this is a class C address hence subnetting occurs on the fourth octet
 The fourth octet value is 0 (255.255.255.0).
 Therefore on looking at the subnet mask and block size table, 0 falls within 128 block
 The block size of subnet mask 128 is 128.
 Therefore we will have two subnets that is (0-127 and 128-255)
In the first subnet(0-127) In the second subnet(128-255)
 network ID= 192.168.10.0 - network ID= 192.168.10.128
 first valid host ID= 192.168.10.1 - first valid host ID= 192.168.10.129
 last valid host ID= 192.168.10.126 - last valid host ID= 192.168.10.254
 broadcast ID= 192.168.10.127 - broadcast ID= 192.168.10.255

4. Examples Classless Subnetting
c. Given network 192.168.10.0 and subnet mask of 255.255.255.192.
- Find network ID, first and last valid host ID, broadcast ID.
 Network= 192.168.10.0
 subnet mask of 255.255.255.192
 Considering this is a classless IP hence subnetting occurs on the fourth octet
 The fourth octet value is 192 (255.255.255.192).
 Therefore on looking at the subnet mask and block size, the block size of subnet mask 192 is 64.
 Therefore we will have 4 subnets that is (0-63, 64-127, 128-191, 192-255)
In the first subnet(0-63) In the second subnet(64-127)
In the third subnet(128-191) In the fourth subnet(192-255)

5. Alternative method of Subnetting
c. Given network 192.168.10.0 and subnet mask of 255.255.255.192.
- Find total number of subnetworks and hosts per subnet
 Network= 192.168.10.0
 subnet mask of 255.255.255.192
Using the above binary-decimal conversion,
Convers subnet mask into binary
11111111.11111111.11111111.11000000
Network bits represented by ones.
Host bits represented by zeros.
 Considering the binary values above, the borrowed network bits are two.
 11111111.11111111.11111111.11000000
 The host bits are six 11111111.11111111.11111111.11000000
Total Number of subnets= 2n -(22)= 4
Total Number of hosts per subnet= 2n-2(26-2)= 62

Class 7: Network Domains,
Data Casting/Transfer methods, Port Numbers
and URL
 What to Cover.
 Network Domains (Broadcast and Collision Domains)
 Data Casting methods
 What is URL
 What is Port Number

1. Network Domains
- Network domain means an area/place/location in a network.
a. Broadcast Domains
- This is an area in a LAN environment.
- Each LAN is a separate broadcast domain.
- When one message is sent to a device, it is goes to all other devices connected in that network.
- It is the domain in which a broadcast is forwarded. A broadcast domain contains all devices that can
reach each other at the data link layer (OSI layer 2) by using broadcast.
b. Collision Domains
- Refers to the part of a network where packet collisions can occur.
- A collision occurs when two devices send a packet at the same time on the shared network segment.
- The packets collide and both devices must send the packets again, which reduces network efficiency.

c. Broadcast Domains of Hub, Switch, Bridge and Router
i. Switch, Bridge and Hub
- They have one broadcast domain even if many ports are connected.
- Here, the broadcast domain do not depend on the number of ports connected.
- Each port is in the same broadcast domain.
- For example, a switch or hub connecting 8 PCs has only one broadcast domain.
i. Router
- The broadcast domain in router is equal to the number of connected ports.
- Depends on the router ports.
- Each port is in a separate broadcast domain.
- For example, a router connecting 8 PCs has 8 broadcast domains.

d. Collision Domains of Hub, Switch, Bridge and Router
i. Hub
- Hub has only one collision domain even if many ports are connected.
- Here, the collision domain do not depend on the number of ports connected.
- Each port is in the same collision domain.
- For example, a hub connecting 8 PCs has only one collision domain.
i. Switch, Bridge and Router
- The collision domain in switch/bridge/router is equal to the number of connected ports.
- Depends on the switch/bridge/router ports.
- Each port is in a separate collision domain.
- For example, a router/switch/bridge connecting 8 PCs has 8 collision domains.

2. Data Casting/Transfer Methods
• unicast addresses – represent a single LAN interface. A unicast frame will be sent to a specific device,
not to a group of devices on the LAN.
• multicast addresses – represent a group of devices in a LAN. A frame sent to a multicast address will be
forwarded to a group of devices on the LAN.
• broadcast addresses – represent all device on the LAN. Frames sent to a broadcast address will be
delivered to all devices on the LAN.

3. What is URL
- Full form of Uniform Resource Locator
- It is a string of characters that contains information about how to fetch a resource from its location.
- It specifies the primary access mechanism and the network location of a resource.
- Consists of the following components:
1. the protocol used to connect to the server (e.g. HTTPS)
2. the server hostname (e.g. geek-university.com)
3. the document path (e.g. /course)
For example;
- ftp://www.geek-university.com/uploads.zip – refers to the uploads.zip file on the geek-
university.com server that can be accessed using FTP

4. What is Port Number
- A port is a 16-bit number used to identify specific applications and services.
- TCP and UDP specify the source and destination port numbers in their packet headers and that
information, along with the source and destination IP addresses and the transport protocol (TCP or UDP),
enables applications running on hosts on a TCP/IP network to communicate.

Class 8: How to Download, Install and use Cisco
Packet Tracer
 What to Cover.
 Download and Installation
 Using the Components and Features
 Basic Cisco IOS Commands Lines and Modes
- obtain from (https://www.omnisecu.com/cisco-certified-network-associate-
ccna/cisco-ios-command-line-modes.php )

Introduction to Networking.pptx

More Related Content

Similar to Introduction to Networking.pptx (20)

Recently uploaded (20)

Introduction to Networking.pptx