What are VPNs?

when two people are having a private

conversation they expect it to be

private to have confidentiality for what

said back and forth well if we're

sending sensitive information over our

networks we also want privacy and

confidentiality for that information

that we're sending back and forth and

one great tool that we can put in our

Batman tool belt the help enforce and

provide confidentiality for data as it

goes across our networks is a virtual

private network of VPN and that's what

we're going to take a look at right here

in this video so let's use this network

topology as a backdrop for our

conversation regarding Virtual Private

Networks and let's imagine this site on

the left here is the headquarter site

and over here we have the branch office

and we've got Bob right here

at the headquarter site and to get

connectivity between the branch office

and the headquarter site they are

leveraging the internet for connectivity

so when Bob sends packets in traffic to

a server over at the branch office that

traffic would go something like this

through the routers through the firewall

through this router through the internet

and all the pieces there and finally end

up at the branch office and at the

server data and the challenge is is that

if there's an eavesdropper anywhere in

that path who is listening to the

traffic they can copy that traffic and

if it's not protected with encryption

they can go ahead and make sense of the

data so if there are sensitive

information going between Bob and the

server of the branch office we've just

ruined confidentiality because the

eavesdropper now has access and can make

sense of that data so one of the

solutions that we can use is to use

encryption and we've touched on this in

a previous nugget but encryption is the

concept of scrambling the data in such a

fashion so that if anybody gets a hold

of it without the right keys to unlock

that data or decrypt that data it's just

a bunch of gobbledygook so the attacker

are the eavesdropper on the internet

eavesdropping on our traffic if it's

encrypted they can't make sense of it

and it's of no value to them so a

question might be well how do we make

sure that all of our traffic is

encrypted well we have a few options

there we have some applications if we

pulled out our smart phone and we are

using a messaging app or some other app

it's very likely that individual

applications are doing encryption before

they're sending data back and forth

between your mobile device and some

other device so the apps could implement

encryption

on their own however the problem is that

that's not going to cover everything

that's going into and out of your phone

over for example a Wi-Fi connection case

in point if Louis with their mobile

device opens up something that runs

telnet telnet is a an application that

can be used to remotely connect to

another system and it's not encrypted so

if Louis opens up a telnet application

that's not encrypted and she starts

communicating over a network that

traffic is then subject to eavesdropping

and the attacker could learn sensitive

information like usernames and passwords

and anything else that the attacker

captured as Louis was communicating

using a protocol a set of rules if you

will that didn't include any type of

confidentiality or encryption so another

answer to the question how do we protect

and encrypt everything would be we could

use a virtual private network and with a

virtual private network everything that

goes to the network adapter once the VPN

is turned on everything is encrypted as

it goes through so if we wanted to

provide confidentiality in encryption

services between everybody at

headquarters office when they talk to

the branch office and vice versa

we could implement our Virtual Private

Network and maybe we put it up the

firewall so that is one end of the VPN

tunnel just to refer to as the path for

the virtual private network and ok to

have that VPN tunnel go from the

firewall all the way up to another

device maybe they have another firewall

up at the branch office up to here

so with this VPN tunnel established

between the firewall at headquarters in

the firewall at the branch office now

Bob over here when he sends traffic it

would go through the switches through

the routers hit the firewall at that

point it would be encrypted and put into

this logical VPN tunnel this VPN path

that goes between this firewall and that

firewall so anybody eavesdropping

anywhere in the tunnel

all they're gonna get is gobbly

because they don't understand how to

decrypt the data the eavesdropper is

known and then once it hits the firewall

at the branch office the firewall there

decrypt it and then it passes it on to

its final destination so if Bob was

talking to a server that's gonna be

transparent to Bob all Bob knows is that

he's communicating with the server and

the firewalls are providing both ends of

the tunnel for the encryption and

decryption respectively now this type of

tunnel that's going between two sites

our branch office site and our

headquarter site it has a special type

of name when we're

connecting two sites together with a

tunnel and it's referred to as a

site-to-site VPN so whenever you hear

the term hey we've got a site-to-site

VPN it just means that there's two

devices one at each end between two

sites that are encrypting and decrypting

the data so it can securely cross over

the network and not be vulnerable to

eavesdroppers but wait there's more

another type of a virtual private

network of VPN that we can build is

referred to as a remote access VPN it

would go something like this we have a

user and let's say that user is on the

internet and let's call that user Larry

so Larry is on the Internet maybe he's

at his home at a hotel and Larry would

like to access a server or some other

resources at the headquarter site but

all he has is the internet to go ahead

and cross to get there so we don't want

to have Larry communicate naked Lea over

the internet because then that traffic

would be subject to eavesdroppers so a

solution is we could have Larry built a

VPN from his computer and build his own

VPN tunnel from his own location all the

way to the edge of our network in this

case we're in have our firewall acting

as the head end device for the VPN so

Larry's computer would have a client or

an application that could build that VPN

tunnel from his device to the

headquarter site and then everything

that goes between Larry and the

headquarter site would all be encrypted

and protected from eavesdropping because

of that VPN tunnel and when an

individual computer could be a mobile

device or a laptop when it build a VPN

tunnel to ahead in site that's referred

to as remote access VPN and when the

benefits of that again is we're

protecting we're encrypting all the

traffic as it goes from Larry's machine

through the VPN tunnel and his computer

his device all the way to the other end

of the VPN tunnel in this example it's

the firewall in this nugget we've

learned about a couple different types

of VPNs and the value they bring to the

table and that is to encrypt data

so anybody eavesdropping on that data

won't be able to make sense of it and

that helps keep our data secure I hope

this has been informative for you and

I'd like to thank you for viewing