CCNA (fifth lecture)

Fifth Lecture 

IP addressing:
what is an ip address ?
An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication.
it consists of 4 digits separated by dot "." each digit has 8 bits , e.g: 192.168.10.1
It is classified into 5 classes:

e.g: Class A: 192.0.0.0

Class B: 192.168.0.0

Class C:192.168.10.0

Class A we can put a lot of devices and it has the largest amount among classes,

Class B contains less, and class C contains the least.

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DNS & DHCP

DNS (Domain Name service)

An internet service that translates domain names into IP addresses and visa verse.

Ex: google IP: 173.194.41.70

DHCP(Dynamic Host Configuration Protocol)

is a network protocol used to assign IP addresses and provide configuration information to devices such as servers, desktops, or mobile devices, so they can communicate on a network using the Internet Protocol (IP).

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CCNA (fourth lecture)

Fourth Lecture

Most important protocols:

And here are the ports number of each protocol, which means the port which packets go from:

Ethernet Cabling 

There are three ways to make your ethernet cable:

•Straight-through cable

• Crossover cable

• Rolled cable

Later I will tell you when we use each of them

Here is the draw of the first way (Straight-through cable)

It's called straight-through because you connect both sides the same way , and the draw above shows the colors and how to connect them correctly.

second way (Cross-over)

Here we connect them in a different way and the colors above show how to.

Third way(Rolled-over)

Here we connect the first one , then the second one is connected in the opposite way .

Now, the question is: when we use the first, second, and the third way ?

Simply, here is the answer:

between these devices we use the cables as the following:

Straight-Through Cable : •Host to switch or hub

                                    • Router to switch or hub

Crossover Cable: •Switch to switch

                           • Hub to hub

                           • Host to host

                           • Hub to switch

                            • Router direct to host

Rolled Cable: It is typically used to connect a computer terminal to the console port of a router
(I will show you later when we use it and how)

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CCNA (third lecture)

Third Lecture
Data Encapsulation 

The OSI Reference Model 

•Open Systems Interconnection

•7-layer

•It divides the network communication process into smaller and simpler components, thus

•aiding component development, design, and troubleshooting.

• It allows multiple-vendor development through standardization of network components.

• It encourages industry standardization by defining what functions occur at each layer of

•the model.

• It allows various types of network hardware and software to communicate.

Upper Layers

Lower Layers

•The OSI reference model has seven layers:

• Application layer (layer 7)

• Presentation layer (layer 6)

• Session layer (layer 5)

• Transport layer (layer 4)

• Network layer (layer 3)

• Data Link layer (layer 2)

• Physical layer (layer 1)

Layer functions

The Application Layer

•interface between the actual application program and the next layer down

•file transfers and email.

The Presentation Layer

•It presents data to the Application layer

•Data translation and code formatting.

•EBCDIC to ASCII translation services

• Data compression and  decompression

•Data encryption, and decryption

The Session Layer

•The Session layer is responsible for setting up, managing, and then tearing down sessions between Presentation layer entities.

•simplex, half duplex, and full duplex.

The Transport Layer

•segments and reassembles data into a data stream.

•connectionless or connection-oriented

•Flow Control

The Network Layer

•Route update packets

•Network addresses

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MAC Addressing 

•Layer 2 Address

•48- Bit

•Hexadecimal

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CCNA (second lecture)

Second Lecture

•Internetworking Basics

•Network Devices

•The OSI Reference Model

•Ethernet Cabling

•Data Encapsulation

•The Cisco Three-Layer Hierarchical Model

•MAC Addressing

•Collision & Broadcast Domains

•CSMA/CD & CSMA/CA 

•TCP/IP  Model

•IP Addressing

•Network & Broadcast Addresses

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Inter-networking Basics 

•LAN : Local Area Network

•WAN : Wide Area Network

•Digital DATA

•Domain

•Peer-Peer

•Services

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Network Devices:

•HUB

 used to connect devices with each other.

the packet goes to every port to find the destination , so it's very slow  and not used these days.

•Bridge : one input and one output port , better than a hub.

•Repeater

•Switch

•Router

•Firewall

•IDS/IPS : intrusion detection system , intrusion prevention system

•SOHO Router

•Modem

•Access Point

•Wireless Repeater

•Wireless Router

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CCNA (first lecture)

First Lecture

What is CCNA ?
CCNA stands for: Cisco Certified Network Associate.

This course is considered as the core of the remaining  network training courses, because it is has the basics of networks and the way how to build your own network from A-Z.

In this course you are going to leran:
•Internetworking
•TCP/IP
•Subnetting & Supernetting
•Internetworking Operating System (IOS)
•Viewing, Saving, and Erasing Configurations
•IP Routing
•Enhanced IGRP (EIGRP) and Open Shortest Path First (OSPF)
•Layer 2 Switching and Spanning Tree Protocol (STP)
•Virtual LANs (VLANs)
•Security
•Network Address Translation (NAT)
•Cisco’s Wireless Technologies
•Internet Protocol Version 6 (IPv6)
•Wide Area Networks
 I will tell you everything in details and you are going to learn them all.
the next page will show you these topics and what will you learn in every topic.

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