Networking Basic

welcome to my comprehensive CCNA course

as this is the first video allow me to

introduce the course and tell you a

little bit about what we have in store

for you this course is designed to be

your one-stop shop for everything you

need to ace the CCNA exam and it's all

completely free we'll be diving into all

the key topics on Cisco's official exam

list with lecture videos to guide you

every step of the way but that's not all

we also have practice quizzes to test

your understanding flashcards to help

you review and remember what you learned

practice labs using Cisco's packet

tracer simulation software and multiple

practice exams to get you ready for the

real thing and don't worry while the

course follows Cisco's official exam

topics list I'll also be providing

additional context and information to

really help you understand the material

and improve your understanding of

networks in general

this course is perfect for anyone who

wants to pass the CCNA 200 to 301 exam

no prior knowledge of networking

required and don't need any experience

in programming so without further ado

let's jump right in now let's discuss

networking to begin let's define what a

network is a computer network is a

digital telecommunication system for

sharing resources between computing

devices that use a common

telecommunications

technology data transmission between

devices is supported through data links

made up of physical cables or wireless

methods such as Wi-Fi or microwave

transmission the point of computer

networks is to share resources such as

information or printers in the past each

person in an office would need their own

printer but with a network a single

printer can be shared by multiple people

reducing cost another example of

resource sharing is file sharing where a

file can be transferred through sneaker

net floppy disc or USB thumb drive

instead of physical transfer the goal of

computer network is to make resource

sharing more efficient and cost

effective

networks come in all different sizes

from the smallest to the largest the

largest network on Earth that we know of

today is the internet it connects people

and devices all over the world but

networks don't have to be that big they

can be as simple as connecting two

computers together in the past to share

information between two computers you

would need to use a physical method such

as copying files onto a USB drive and

transferring it manually nowadays

networks typically use cables such as

Ethernet cables to connect

devices one example is the use of a RJ45

connector commonly known as an Ethernet

cable which connects devices through a

physical connection however with

advancements in technology wireless

methods such as Wi-Fi have become

increasingly popular as it makes

connecting and sharing information much

easier for example connecting two

smartphones together using Wi-Fi or

Bluetooth instead of a physical cable is

a common way people share information

today the idea of using cables like we

used to might seem crazy to young people

today as they expect it to be easy and

effortless to connect and share

information across

devices now let's talk about the two

main players in the game servers and

clients a server is like a superhero

providing all the resources and

capabilities that clients need to access

think of it like a big and powerful

computer that has all the storage memory

and processing power to handle multiple

requests at once but just like any

superhero it can't do it alone and

that's where clients come in clients are

the sidekicks they access the services

provided by the server and make use of

them imagine your laptop or phone as the

client reaching out to the server to get

the information it needs but just like

the server a client can also switch

roles and become a server itself it can

share resources or host services for

other clients to access now let's

imagine you're sitting in front of your

laptop and you want to access Google you

type in the web address and hit enter

that's the client reaching out to the

server which is Google in this case to

get the web page and boom Google sends

back the page and displays it on your

screen this process happens so quickly

and seamlessly that we often take it for

granted the original Ethernet used a

large yellow cable called 10b 5

repeaters were developed to amplify the

signal allowing the cable to be longer

without signal

attenuation multiple port repeaters also

called hubs were also developed to

repeat the signal from one port to

multiple other ports

these devices did not understand the

signal they only amplified it nowadays

hubs are considered obsolete but

wireless access points which allow

multiple devices to connect wirelessly

can be considered a type of hub a switch

is a more advanced device that allows

for multiple devices to connect and

communicate on a network without

collisions unlike a hub switches are

more advanced than hubs because they

have the ability to forward and filter

data based on the MAC address of the

devices connected to it this allows for

more efficient use of the network as

well as greater security when a device

sends a data packet to the network the

switch will check the destination MAC

address and forward the packet only to

the port connected to the device that

the packet is meant for this eliminates

the possibility of data collisions and

improves overall network

performance switch can come in different

size with varied ports some switches are

small with a few ports while others have

a large number of ports routers are

devices that are used to connect

different networks and direct traffic

between them they use routing tables and

protocols to determine the best path for

data packets to take as they travel

between networks

routers operate at the network layer OSI

layer 3 and perform tasks such as IP

address assignment subnet masking and

network address translation

NAT routers can connect networks of

different types such as LANs and WANs

and can also be used to connect networks

of the same type such as connecting

multiple LANs one of the main functions

of a router is to act as a gateway

between different networks

in summary routers are devices that

directs traffic between networks it uses

routing tables and routing protocols it

can connect different types of networks

and also can connect multiple networks

of the same type they come in different

forms from homegrade routers to

enterprisegrade routers with more

advanced features

a firewall is a security system that is

used to prevent unauthorized access to a

private network by filtering the

incoming information from the internet

its main purpose is to create a barrier

between a private network and the public

internet to protect it from hackers and

malicious traffic firewalls block

unwanted traffic and only permit wanted

traffic and it's especially important

for large organizations that had a lot

of computers and servers a firewall

works by filtering incoming network data

and determining whether it should be

allowed to enter a network based on

rules called an access control list

these rules are customizable by the

network administrator and can be based

on IP addresses domain names protocols

programs ports and keywords

there are different types of firewalls

including hostbased firewalls which are

software firewalls installed on a single

computer and many operating systems and

third party software come with built-in

hostbased firewalls another type of

firewall is the network-based firewall

also known as a packet filtering

firewall which sits at the network

perimeter and controls access to the

entire network

this type of firewall inspects each

packet of data that travels through it

and allows or denies access based on

predefined

rules network-based firewalls can also

be hardware or softwarebased and are

typically used in larger organizations

to provide more advanced security

features such as stateful inspection

which tracks the state of a connection

and ensures that only authorized traffic

is allowed to pass through another type

of firewall is the stateful inspection

firewall also known as a dynamic packet

filtering firewall which inspects not

only the header information of a packet

but also the context in which the packet

was sent such as the type of data being

transferred and the status of the

connection this allows it to detect and

block potentially malicious traffic that

may otherwise pass through a packet

filtering firewall lastly there are next

generation firewall is a type of

firewall that combines traditional

firewall features with intrusion

prevention application control and other

security features to provide a more

comprehensive security

solution next generation firewalls can

also offer additional features like

advanced threat protection and user

identity management in summary a

firewall is a security system that is

used to prevent unauthorized access to a

private network by filtering incoming

information from the internet firewalls

come in different types including

hostbased network-based stateful

inspection and next generation firewall

each with their own set of features and

level of protection they provide and

they can be hardware or softwarebased

thanks for tuning in that's all for this

video