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Chapter one                             Introduction :-

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Chapter one                             Introduction :-

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*Network is an interaction between two or more devices that able to send or receive(get) data .
*Network used to share files and information such as (email,photo,video,voice ...etc).
For example/  (internet) is defined as a global network of network, or Mobile communication (such as asiacell or korek) is described as wireless network .

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1-Device:- there are 2 types of network device:-
A/End-user devices(which generate messages)
B/Intermediary devices (make possible to deliver data from source to destination)
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2-Medium:-provides the channel over which the message travels from source to destination ,
There are 3 types of it :-
A/Copper(most common type)
B/Fiber optic(fastest type)
C/Wireless
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3-Rule&service:-are the standards and protocols that specify how the messages are sent and how they directed through the network.
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4-Messages:-
the file that you want to send (a document file , photo , video ...etc) .

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LAN:- stands for (local Area Network) usually spans in one place or a organization, such as  a room of a company.
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WAN:-Stands for(Wide Area Network) networks that connect LANs in separated places which are referred to as wide area network, such as internet .
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Internet:- created by the interconnection of networks belonging to internet service providers (ISPs).
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Intranet:-it refers to a private connection of LANs and WANs that belongs to an organization.

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Chapter one                 What we learned ?

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Chapter one                 What we learned ?

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At the end of the chapter we learned about what network is and what its purpose with two example , we learned about what are the elements of network,difference between (LAN ,WAN) and (Internet,intranet) .
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--Thanks to
Mr.miran
========================

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Chapter two  Part one                 Network representation 

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Chapter two  Part one                 Network representation 

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*NIC:- stands for (network interface card) or we can call it LAN adapter , provides the physical connection to the network at the pc or other host device .
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*Physical port:- a connector or outlet on a networking device where the media is connected to a host or other networking device .

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*UnShielded twisted-pair (UTP) cable :-
consists of four pairs of color-coded wires that have been twisted together and then encased in a flexible plastic sheath.
*Shielded twist-pair (STP) cable :- shields the entire bundle of wires within the cable as well as the individual wire pairs.
Note/it provides a better noise protection than (UTB) cable .

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*(UTP) cabling , terminated with RJ-45 connectors , is common copper-based medium for interconnecting network devices.
*The individual wires in the cable have to be connected in different ways to different sets of pins in RJ-45 connectors ,
Here are the types of cable:-
1-Straight(to connect different devices)(ex/
switch to router
hub to PC
Hub&switch-Router&PC)
2-Crossover(to connect same type of devices)(ex/
switch to hub
router to PC
Hub&switch-Hub&witch)

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*Physical topology :- is refer to the shape of the network (how network devices connected to each others)
Types:-
1-Ring
2-Star
3-Mesh
4-Tree
and more ....
Note/They have different advantage and disadvantage .
*Logical topology:-defines how the data should transfer , contrast this to the physical topology which consists of the layout of cables , network devices and wiring.

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Chapter two  Part one                                                            What we learned :-

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Chapter two  Part one                                                            What we learned :-

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At the end of the chapter we learned about NIC and physical port(connector or outlet),also we learned about types of transmission medium , we talked about (UTP and STP) .
We learned about about RJ-45 and its type of connecting(straight and crossover) , the final part of lecture was network topology(physical and logical) .
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--Thanks to
Mr.miran
========================

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Chapter two Part two                                                  Logical Topology

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Chapter two Part two                                                  Logical Topology

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The logical topology defines how the data should transfer.
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Network Protocols :-
describe processes such as :-
1- The format of the message .
2- How and when error and system messages are passed between devices .
-----------------------------Network Protocols Standards :-
A standard is a process or protocol that has been endorsed by the networking industry and ratified by a standards organization like ( the Institute of Electrical and Electronics Engineers (IEEE) ) or ( Internet Engineering Task Force (IETF) )
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There are 2 types (protocol models and reference models)
-A reference model is not intended to be implemented or to provide a sufficient level of detail to define precisely the services of the network architecture.
Note/The main purpose in using reference model is to aid in clearer understanding of the functions and process involved.
Example/Open Systems Interconnection (OSI).
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-Protocol model provides a model that closely matches the structure of a particular protocol suite.
Note/ Control Protocol/ Internet Protocol (TCP/IP) model is a protocol model because it describes the functions that occur at each layer.

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It describes the functionality of the protocols that make up the TCP/IP protocol suite( which are implemented on both the sending and receiving hosts).
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How it works?
1. Creation of data ...
2. Segmentation and encapsulation of data ...
3. Generation of the data ...
4. Transportation of the data ...
5.Reception of the data  ...
6. De-capsulation and reassembly of the data ...
7. Passing this data to the destination application
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-Layer 2 is concerned with the delivery of messages form a node to another node , Layer 2 address represents the address of the end device.
-Note/It is called the Media Access Control (MAC) address.

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Note/Each application, service is represented at Layer 4 by a port number.
- A unique dialogue between devices is identified with a pair of Layer 4 source and destination port numbers that are representative of the two communicating applications .

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Chapter two Part two                                           What we learned :-

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Chapter two Part two                                           What we learned :-

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Well in Ch2_P1 we talked about logical topology and in this chapter we got it again , after that we learned about network protocols and their standards , we learned about layered model (Reference , protocol) and their most important examples (TCP/IP and OSI) , the last thing is we learned about addressing in the network which consists of 4 layer .
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--Thanks to
Mr.miran
========================

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Chapter three                                                       Network accessing devices

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Chapter three                                                       Network accessing devices

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1- Repeater:-
It receives a digital signal and regenerates it,  Then forwards the digital signal to the output port.
It is used to overcome the attenuation problems due to the cable length.
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2-Hub:-
It is really a multiple-port repeater,  signal received from a port on a hub port is regenerated or reamplified and transmitted out all ports on the hub .
Notes/
- It works only at the PHY layer .
- If two PCs send their packets at the same time! Collision will occur.
- Because packet can collide with each other, both Repeater and Hub have one collision domain.
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3- Bridge:-
It is a data link layer (layer 2 of OSI) device, each of its ports is in a separate collision domain, Filter traffic between network segments by examining the destination MAC address.
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4- Switch:-
It  is basically just a multiple-port bridge with more brainpower, management ability and features.
Main reason in using it:-
- Dedicated bandwidth to each port
- Collision-free environment
- Full-duplex operation

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1- Learning
2- Aging
3- Flooding
4- Selective Forwarding
5- Filtering
Notes/
- A switch does not send a frame to the same port on which it got it.
-It  will also drop a corrupt frame.
-It also has security settings for blocking frames to and/or from selective MAC addresses or specific ports.

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It is intermediary device (from Layer 3) which user can access through network in it.
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-Router- Gateway
Gateway is a router interface connected to the local network, its interface has a Network layer address.
The hosts are configured to recognize that address as the gateway.
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-Router- Routing
Routing used to forward a packet to a destination network, the router requires a route to that network.
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-Router - Routing Table:-
It stores information about connected and remote networks.
Connected networks are directly attached to one of the router interfaces.

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Router can do 3 type of operation :-
1- Forward it to the next-hop router .
2- Forward it to the destination host .
3- Drop it .
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Routing - Table:-
It  contains the information that a router uses .
Also it needs to represent the most accurate state of network pathways which router can access.
Note/ This route information can be manually configured on the router (static routing) or learned dynamically (dynamic routing) from other routers in the same internet work .

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Chapter three                                                         What we learned:-

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Chapter three                                                         What we learned:-

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We learned about network access devices which we can access through a network with it and we learned where or which layer they work at , we focused on switch and router , how they work .
========================
--Thanks to
Mr.miran
========================

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Chapter Four                                                           IP address

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Chapter Four                                                           IP address

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In the Network layer (layer 3) , the packets need to get identified with the source and destination addresses of the two end device with IPv4 .
Which means each packet has a 32-bit source address and a 32-bit destination .
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There are 2 kind of conversation in ip address:-
-Decimal->Binary
-Binary->Decimal
Both needs to be known .

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IP address - Network and Host Portions:-

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IP address - Network and Host Portions:-

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-The high-order bits represents the network portion. we define a network as a group of hosts that have identical bit patterns in the network address portion of the address .

-The lower-order called the host portion of the address and The number of bits used in this host portion determines the number of hosts that we can have within the network.
However all 32 bits define the IPv4 host address

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There are three types of IP addresses :
- Network address :-  is a standard way to refer to a network. All hosts in the network will have identical network bits.
Note/ We can find the network address by making all host portion bits to 0 .
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- Broadcast Address: to send data to all hosts in a network, a host can send a single packet that is addressed to the broadcast address of the network.
Note/ We can find the broadcast address by making all host portion bits to 1 .
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- Host Addresses:  we assign the values between the network address and the broadcast address to the devices in that network

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It is a number of the bits in the address that represent the network portion .
For example, in 192.168.4.5 /24, the /24 is the prefix and it tells us that the first 24 bits are the network portion .
Note/This leaves the remaining 8 bits, the last octet, as the host portion.

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Subnet mask provides the same information as network prefix while looks different .
For example, in 192.168.4.5/24,  The /24 is the prefix length ,  The subnet mask is 255.255.255.0  which comes from the first 24 bits of the ( network portion)

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In an IPv4 network, the hosts can communicate in three different ways (only one at same time):-
- Unicast
The process of sending a packet from one host to an individual host
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- Broadcast traffic
Is used to send packets to all hosts in the network, a packet uses a special broadcast address.
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- Multicast transmission
Allowing a host to send a single packet to a selected set of hosts.

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Chapter three                                                what we learned :- 

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Chapter three                                                what we learned :- 

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In this chapter we learned about IP addresses , Network and host portion.
we knew what are the types of IP addresses also we learned network prefixes and subnet.
at the end of the chapter we learned about types of communications .
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--Thanks to
Mr.miran
========================

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Chapter five                                                        Public and private addresses

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Chapter five                                                        Public and private addresses

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Public addresses designated for use in networks that are accessible on the Internet , but  private addresses are used in local networks that require no Internet access.
The private address blocks are:
- 10.0.0.0 to 10.255.255.255 (10.0.0.0 /8)
- 172.16.0.0 to 172.31.255.255 (172.16.0.0 /12)
-  192.168.0.0 to 192.168.255.255 (192.168.0.0 /16)
Note/ Packets using private addresses as the source or destination should not appear on the public Internet

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- Class A Blocks
this class was designed to support extremely large networks with more than 16 million host addresses. Class A IPv4 addresses used a fixed /8 prefix.
This restricted the address block for class A is
0.0.0.0 /8 to 127.0.0.0 /8.
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- Class B Blocks
Class B Was designed to support the needs of moderate to large size networks with more than 65,000 hosts .
This restricted the address block for class B
128.0.0.0 /16 to 191.255.0.0 /16.
Note/ There were only 16000 possible class B networks .
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- Class C Blocks
This address space was intended to provide addresses for small networks with a maximum of 254 hosts .
Class C address blocks used a /24 prefix.
This restricted the address block for class C is 192.0.0.0 /24 to 223.255.255.0 /24 .
Note/ It could provide addresses to 2 million networks

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- Static assignment of addresses :-
The network administrator must manually configure the network information for a host with a static assignment .

It is useful for printers, servers, and other networking devices that need to be accessible to clients on the network.
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- Dynamic assignment of addresses :-
End user devices often have addresses dynamically assigned, using Dynamic Host Configuration Protocol (DHCP) ,  DHCP enables the automatic assignment of addressing information such as IP address, default gateway , subnet mask.

Note/ Benefit of DHCP is that an address is not permanently assigned to a host but is only "leased" for a period of time.

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Chapter five                                                        what we learned :-

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Chapter five                                                        what we learned :-

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In this chapter we learned about privet and public address.
we learned about IP address classes (A,B,C) and their info.
in the final part we learned about Dynamic and static assignment and their benefit.
========================
--Thanks to
Mr.miran
========================

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Chapter six                                                            Classify and Define IPv4 Addresses 

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Chapter six                                                            Classify and Define IPv4 Addresses 

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Name the three types of addresses in the network and describe the purpose of each type and a example of them:-

-Network addresses (10.0.0.0)

-Broadcast addresses(10.0.0.255)

-Host addresses

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Subnetting allows for creating multiple networks from a single address block, Or  dividing one big network ( /16 or /24) into multiple smaller ones ( /27, /28).
Note/ Or simply, dividing one big network ( /16 or /24) into multiple smaller ones ( /27, /28).
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How to do subnetting

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- You just work on host bits .
- The deducted bits form host portion will be addes to the original subnet mask .
- Number of the deducted bits specifies the number of the subnets.
- Number of the remaining host bits specifies the number of the usable host in each subnets .

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Chapter seven                                                              OSI AND TCP/IP MODELS 

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Chapter seven                                                              OSI AND TCP/IP MODELS 

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The Application layer is the layer that provides the interface between the applications that we can use to communicate .

Application layer protocols are used to exchange data between programs running on the source and destination hosts.
The functionality of the TCP/IP application layer protocols fit roughly into the framework of the top three layers of the OSI model Application, Presentation and Session layers.

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It has three primary functions:
- Coding and conversion of Application layer data
- Compression of the data
- Encryption of the data for transmission and the decryption of data upon receipt by the destination.

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It is responsible for setting up, managing, and then tearing down sessions between Presentation layer entities.
It serves to organize their communication by offering three different modes: simplex, half duplex, and full duplex.
Note/ the Session layer basically keeps different applications data separate from other applications data .

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The most widely-known TCP/IP Application layer protocols are those that provide for the exchange of user information. Among these TCP/IP protocols are:
- Domain Name Service Protocol (DNS)
It is used to resolve Internet names to IP addresses.
- Telnet
It is a terminal emulation protocol, is used to provide remote access to servers and networking devices.
- File Transfer Protocol (FTP)
It isused for interactive file transfer between systems.

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- Applications
They are the software programs used by people to communicate over the network.
- Services
They are the programs that interface with the network and prepare the data for transfer.
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MODEL OF GATHERING INFORMATION
- The Client/Server model
The device requesting the information is called a client and the device responding to the request is called a server.

-Peer-to-peer model
In this model two or more computers are connected via a network and can share resources without having a dedicated server.
Note/ Every connected end device known as a peer.

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APPLICATION LAYER PROTOCOLS AND SERVICES

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APPLICATION LAYER PROTOCOLS AND SERVICES

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Port numbers identify applications and Application layer services that are the source and destination of data.
Server programs use predefined port numbers that are known by clients commonly .
Note/
UDP - User Datagram Protocol
TCP - Transmission control protocol
Some of these services port numbers are :
- DNS --> TCP/UDP Port 53
- HTTP --> TCP Port 80
- Telnet --> TCP Port 23
- DHCP --> UDP Port 67
- FTP --> TCP Ports 20 and 21

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DYNAMIC HOST CONFIGURATION PROTOCOL(DHCP) 

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DYNAMIC HOST CONFIGURATION PROTOCOL(DHCP) 

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It enables devices on a network to obtain IP addresses and other information from a DHCP server( This service automates the assignment of IP addresses, subnet masks, gateway and other IP networking parameters).
Note/ DHCP is preferred mostly On (larger local networks, where the user population changes frequently , New users).
Note/ DHCP distributed addresses are not permanently assigned to hosts but are only leased for a period of time.

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Chapter six                                                        what we learned 

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Chapter six                                                        what we learned 

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In this lecture/chapter we learned about IPV4 and its types (Network,broadcast,host).
more than half of this chapter was about subnetting (simple subnetting,Tips,subnetting a subnet ) .
========================
--Thanks to
Mr.miran
========================

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Chapter seven                                                                       what we learned 

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Chapter seven                                                                       what we learned 

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We learned about OSIand TCP/IP models,presentation layer, session layer and (application layer protocols and services).
At the final part of the chapter we learned about DHCP .
========================
--Thanks to
Mr.miran
========================