What is a ROUTER? // FREE CCNA // EP 2

Summary

This CCNA course episode, sponsored by Boson Software, dives into the role of routers in networking. It explains how routers connect different networks and the internet, using a virtual lab to demonstrate packet transmission. The video covers ARP, IP addressing, and the significance of gateways in routing traffic. It also previews DNS and HTTP processes, showing how a user's request to access a website is handled at a technical level, all while giving away Boson NetSim licenses to lucky viewers.

Takeaways

• 🎓 This is the second episode of a free CCNA course sponsored by Boson Software, which provides the best CCNA and CCNP labs and practice exams.
• 🌐 Routers are essential networking devices that connect us to the internet and other networks, serving as the gateway to different networks.
• 🔍 The video demonstrates how routers and switches work together, with routers being responsible for directing traffic between different networks based on IP addresses.
• 🏆 Boson Software is giving away five copies of their netsim product, which is a top choice for CCNA and CCNP labbing.
• 🖥️ The script uses a practical example with a Raspberry Pi named Johnny to illustrate how a device on one network can access resources on another network through a router.
• 📦 IP addresses are crucial for defining network boundaries, and different groups of IP addresses represent different networks.
• 🔄 The Address Resolution Protocol (ARP) is used to find the MAC address associated with an IP address, which is necessary for communication within the same network.
• 🚪 The concept of a 'gateway' in networking is essentially a router that helps devices in one network reach devices in another network.
• 🛰️ Routers have a routing table, which acts as a map to direct packets to their correct destinations based on IP addresses.
• 🌐 The script gives a sneak peek into the complexity of internet routing, showing that routers on the internet have extensive routing tables to direct traffic to countless networks.
• 📚 The video concludes with a call to action for viewers to join a community for further learning and support, emphasizing the importance of continuous education in networking.

Q & A

What is the main focus of the second episode of the free CCNA course?

The main focus of the second episode is to explain the function of routers in connecting networks and facilitating internet access, as well as demonstrating how data packets and frames traverse a network to access a web server.

Who is the official sponsor of the CCNA course mentioned in the script?

Boson Software is the official sponsor of the CCNA course.

What is the purpose of a router in a network?

A router's purpose is to connect different networks, allowing data to be transferred between them, and to facilitate access to the internet.

What is the significance of the gateway in the context of the script?

The gateway, in this context, refers to the router's IP address that a device uses to connect to networks outside of its own local network.

How does a switch differ from a router in terms of network communication?

A switch operates at Layer 2 of the OSI model and uses MAC addresses to forward frames within the same network, while a router operates at Layer 3 and uses IP addresses to route packets between different networks.

What is ARP and why is it used in the script?

ARP (Address Resolution Protocol) is used to find the MAC address associated with an IP address on a local network. It is used in the script to demonstrate how devices discover the MAC addresses needed to communicate within the network.

What does the script reveal about the process of accessing a website from a local network?

The script reveals that accessing a website involves resolving the website's domain name to an IP address using DNS, and then sending HTTP requests through routers and switches to retrieve the website's content.

What is Boson Netsim and why is it being given away in the script?

Boson Netsim is a CCNA and CCNP labbing software used for practice. It is being given away in the script as a promotion to encourage viewers to participate in the contest and potentially win a copy of the software.

How does the script illustrate the concept of IP addressing and network separation?

The script uses two different sets of IP addresses to represent separate networks and demonstrates that devices within the same range are on the same network, while those outside the range are on different networks.

What is the role of a DNS server in the context of the script?

The DNS server resolves domain names to IP addresses, which is necessary for a device to access websites using their friendly names instead of IP addresses.

What command is used in the script to view the routing table of a Cisco router?

The 'show ip route' command is used to view the routing table of a Cisco router, which contains a map of IP addresses and how to reach different networks.

Outlines

00:00

🌐 Introduction to Routers and Networking

This paragraph introduces the concept of routers and their fundamental role in connecting networks. The speaker expresses gratitude to Boson Software for sponsoring the free CCNA course and encourages viewers to check out their CCNA and CCNP labs and practice exams. The video aims to explain the necessity of routers, their function in networks, and how data packets traverse through them to access the internet. The speaker also announces a giveaway of Boson Netsim, a popular labbing software for networking professionals, and sets the stage for a demonstration on how a frame and packet move across a network.

05:00

🔍 The Role of Routers in Network Communication

The speaker delves into the specifics of how routers operate to connect different networks, using the analogy of Johnny wanting coffee from a server on a different network. It explains the limitations of switches and the need for routers to facilitate communication across separate networks. The paragraph discusses the physical aspects of routers, differentiating them from switches and home routers, and introduces the concept of IP addresses and how they define network boundaries. The speaker also demonstrates the process of removing a router to illustrate the point that direct switch-to-switch connections do not bridge network divides.

10:00

📦 Router Configuration and ARP Process

This section covers the basic configuration needed for routers to function effectively, emphasizing that unlike switches, routers require setup to understand how to route between networks. The speaker uses the example of Johnny trying to ping a coffee server to explain the Address Resolution Protocol (ARP) process. It details how ARP allows devices to discover the MAC address of the target device by broadcasting a request within the local network. The paragraph also touches on the concept of gateways and how devices recognize when to use a router to reach destinations outside their local network.

15:02

🌐 Router Magic: How Data Reaches the Destination

The speaker continues the exploration of router functionality by illustrating how Johnny's computer communicates with a coffee server through a router. It explains the process of sending ARP requests to the router to discover its MAC address and how routers use their internal routing tables to determine the best path for data to travel. The paragraph demonstrates the interaction between Johnny's computer, the router, and the coffee server, highlighting the router's role in translating layer 3 (IP) addresses to layer 2 (MAC) addresses to facilitate data transfer.

20:03

🌐 DNS and Accessing Websites

This paragraph introduces the Domain Name System (DNS) and its importance in translating human-readable website URLs into IP addresses that networks understand. The speaker shows a demonstration of Johnny accessing a website by typing a URL, which triggers a DNS query to resolve the site's IP address. It explains the process of Johnny's computer learning the MAC address of the DNS server through ARP and then receiving the IP address for the website. The paragraph concludes with a sneak preview of visiting a website and the underlying networking processes involved.

🚀 Conclusion and Future Topics

The speaker wraps up the episode by summarizing the key points covered and hinting at more complex routing topics to be discussed in future episodes. They encourage viewers to ask questions, seek help, and join their Discord community for further support. The paragraph also acknowledges Boson Software's sponsorship and invites viewers to participate in a giveaway. The speaker teases upcoming content and ends the episode with a reminder of the importance of routers in networking.

Keywords

💡CCNA

CCNA stands for Cisco Certified Network Associate, which is an entry-level certification program for network engineers. It is the focus of the video's course, and the script discusses the importance of this certification in networking. The video is part of a free CCNA course, indicating the educational intent and target audience.

💡Boson Software

Boson Software is mentioned as the official sponsor of the CCNA course in the video. They provide CCNA and CCNP labs and practice exams, which are essential tools for individuals preparing for these certifications. The script encourages viewers to check out Boson Software, highlighting their support for the free educational content.

💡Router

A router is a networking device that forwards data packets between computer networks. In the context of the video, routers are depicted as essential for connecting to the internet and other networks. The script explains how routers operate and their role in facilitating communication across different networks, using the analogy of Johnny wanting coffee from a different network.

💡IP Address

An IP address is a numerical label assigned to devices connected to a computer network that uses the Internet Protocol for communication. The script discusses how IP addresses are used to identify and communicate with devices across networks, with different ranges of IP addresses representing different networks.

💡Switch

A switch is a networking device that connects devices together on a computer network by using packet switching to receive, process, and forward data to the destination device. The video script explains how a switch operates within a local network, allowing devices like Johnny's Raspberry Pi to communicate with each other.

💡ARP (Address Resolution Protocol)

ARP is a protocol used for mapping an IP address to a physical (MAC) address on a local network. The script describes the ARP process, where Johnny's device sends out an ARP request to discover the MAC address associated with an IP address, which is necessary for communication at the data link layer.

💡Layer 2 and Layer 3

Layer 2 and Layer 3 refer to the data link layer and the network layer of the OSI model, respectively. Layer 2 is about MAC addresses and physical connectivity, while Layer 3 is about IP addresses and routing. The script uses these terms to differentiate between the operations of switches (Layer 2) and routers (Layer 3).

💡Gateway

In networking, a gateway is a node on a network that acts as an entrance to another network. The script mentions the gateway as the IP address of the router that devices use to connect to networks outside their local network, illustrating how Johnny's device uses the gateway to reach the coffee server on a different network.

💡DNS (Domain Name System)

DNS is the system that translates human-friendly domain names (like networkchuck.coffee) into IP addresses that computers use to identify each other on the network. The script explains the role of DNS in resolving domain names to IP addresses, which is necessary for Johnny to access the coffee website.

💡Packet Tracer

Packet Tracer is a network simulation tool that allows users to create virtual networks and perform experiments. The script uses Packet Tracer to demonstrate how data flows through a network, including the process of ARP, routing, and DNS lookup in the context of Johnny trying to access a coffee server.

💡HTTP GET Request

An HTTP GET request is a message sent from a client to a server to request a resource from the server. In the script, Johnny uses an HTTP GET request to ask for the webpage from networkchuck.coffee, illustrating the process of accessing a website over the internet.

Highlights

Introduction to the second episode of a free CCNA course sponsored by Boson Software, offering CCNA and CCNP labs and practice exams.

Explanation of the function of routers in connecting to the internet and other networks.

The necessity of routers for accessing resources on different networks, illustrated with the 'Johnny wants coffee' scenario.

Demonstration of how a switch operates within the same network using ARP to resolve MAC addresses.

The difference between a network switch and a router, and why routers are essential for inter-network communication.

Visual representation of connecting routers to networks using a virtual Cisco 2911 router.

Discussion on IP addressing and how it differentiates networks, crucial for router operation.

Experiment to show the limitations of switches without a router when trying to reach a different network.

Illustration of the process of pinging a device on a different network and the role of the gateway in this process.

Explanation of how routers use ARP to learn the MAC addresses of other devices for routing.

The concept of DNS and its role in resolving domain names to IP addresses for web browsing.

Demonstration of a web browser accessing a website and the underlying DNS query process.

Overview of how routers are configured with routing tables to direct traffic to different networks.

Introduction to more complex routing concepts and a preview of routing protocols used on the internet.

Invitation to join a community for further learning and assistance with networking concepts.

Conclusion of the episode with a call to action to try Network Chuck's coffee and participate in the giveaway.

Acknowledgment of Boson Software's support for the free CCNA course and promotion of their products.

Transcripts

this is episode 2 of my free

ccna course and a huge shout out to

boson software the official sponsor of

the ccna course

they are the reason this can be made

available for free so i highly encourage

you to go check them out

they have the absolute best ccna ccnp

labs and practice exams

this is a router but what is it routers

connect us to the internet they also

connect this to other networks

in this video we're going to see why we

need them and what they do in our

networks

and why i have so many of them holy junk

sauce

and of course we're going to be lobbying

we're going to watch how a frame and

then a packet will go across a network

access a web server and then give us

information back this is how the

internet works

you're going to learn that today let's

get started

[Music]

oh by the way i'm giving away some bozon

netsim today on this video

don't know what netsim is what's the

best ccna and ccnp

labbing software in the business so if

you're going for your ccna or ccnp

enterprise or anything that you're doing

cisco it's what you want it's what you

need i'm giving away five copies of any

of those products

link below to enter the contest hurry up

it's going away soon

johnny wants some coffee and we're gonna

help him get it check this out in our

last video we talked about this guy

right here

a switch he's got multiple ports you

connect your computers to him

and they can talk and that's exactly

what's happening here johnny mark

denny and lisa are all on the same

network and the switch allows them to

talk to each other

and in our last video we explored how

the switch actually helps them talk

what goes on inside this thing and it's

it's pretty cool but you see now johnny

this is

this is johnny in real life he's a he's

a raspberry pi johnny doesn't want to

just talk to lisa mark and denny

johnny wants coffee the coffee is

actually way over here

on a completely different network and

johnny's over here not good right how

does johnny get coffee and when i say

johnny wants coffee of course he wants

to go out to networkchuck.coffee and

order some coffee but this server where

this website lives

networkchuck.coffee is on a different

network here the switch can't help him

he needs help from somebody else

he needs a router this guy right here

oh this guy this is a cisco 2911 router

one of my favorites oh it's beautiful

now routers come in all shapes and sizes

this is just one type of cisco router

this is a ubiquiti router looks very

different and then typically your home

routers look nothing like what i just

showed you a router is the perfect

solution for this because a router's job

is to connect

networks let's put one on there this is

actually a virtual version of a 2911

router look

just like the one i showed you how neat

so we'll put the router in between

and notice on a cisco router there's no

ports on the front they're all in the

back so let me turn that slicker around

now plug johnny's switch in to the

router

and then i'll plug the copy network into

the router as well

let's do that in virtual world bam bam

and once more

now before we keep going i want to ask

you a question do we actually need this

router

i mean why can't we just do this let's

take away our connections

move this router out of the way and then

let's just connect our switches directly

to each other

that should work right no no well here's

why

i mean we could connect these two

switches and make them one giant switch

and that's essentially what would happen

but the reason these guys over here and

then my coffee server over here on

different networks

isn't because they're connected to two

different switches that's not it it's

because of these guys right here

their ip addresses we will go more in

depth on this later because

there's a lot more to it but just know

that when we talk about a network

we're normally referring to ip addresses

and a group of ip addresses

so notice i have two groups of ip

addresses here

10.1.1.0 through 10.1.1.255.

with my configuration as long as you

have an ip address in that range

you're on the same network now this

right here 23.27.38.0 through 232738255

that's a completely separate network but

you know what don't take my word for it

let's actually try this let's see if

it'll work

let's go back to packet tracer now as a

quick 30 second refresher on how a

switch works we'll have johnny try to

ping mark over here

and then we'll have him try to ping my

copy server over here and see what

happens so i'll click on johnny wake him

up come on johnny let me get this stuff

out of the way we'll go to his desktop

we'll go to his command prompt

and let's bring up a simulation real

quick so we'll click on the simulation

button at the bottom right

so we can watch this stuff happen in

bullet time and i'm going to show you

something that i did not show you on the

last video

and that's how johnny will learn mark's

mac address now why is it so important

for johnny to learn

mark's mac address well if you recall

from our last video the switch

the only language he speaks is layer two

that's all he knows

mac addresses this layer two address

right here now when johnny pings mark

he's gonna be pinging his ip address so

his message when he gets it ready we'll

be pinging

10.1.1.2 if johnny were writing a letter

that's what he would put as the address

but if that's all johnny had when he

sent this message to the switch the

switch would be like

why is this envelope blank i can't even

see ip addresses who is this going to

that's what would happen so johnny must

know the mac address of mark

in order for the switch to know how to

get it to anywhere but how

this is what happens so from johnny i'm

going to ping mark's ip address 10.1.1.2

and boom let's watch what happens all

right johnny's got some envelopes he's

ready to send them out

these are frames right now notice we

have a new message we're dealing with

it's called arp or addressed resolution

protocol essentially it's a way that

johnny can find out

what mac address is tied to 10.1.1.2

because he has to know that to be able

to send it to mark let's open that up

and see what's inside let's click on

that

and again we're dealing with layer 2 mac

addresses but also notice down here we

have some information about this arp

packet like for example the source ip is

johnny's source ip 10.1.1.3 and then the

destination ip right here

10.1.1.2 that's the missing mac address

he's trying to find out mark's mac

address and then of course because this

is a layer 2 frame we're talking about

mac addresses so the source mac address

that the switch will use is johnny's mac

address but then look at the destination

what the junk is that ffffffff this is

what's called a broadcast address it's

the layer 2 switch equivalent of someone

going

who belongs to 10.1.1.2

when he sends it to that mac address

it's going to go out to everybody

watch what happens we'll click next it

goes to the switch let's open up that

packet and take a look

or frame i'm sorry see it happens now

look at this this is so cool so

over here the switch receives it and

then it's about to send it out and

notice

it's going to go out all these ports on

layer one which remember layer one's the

physical it's these

ah i just unplug something out oh that

sound it's all the physical stuff so

let's click next

and boom art message is going everywhere

and what will happen is lisa will go oh

i'm not 10.1.1.2 and neither

am i says denny but mark

yeah mark is 10.1.1.2 so he says hey

that's me i'm your guy i'm over here

johnny so we'll step forward in time

mark is the only one who responds saying

yes that is me so he'll send and then

the switch sends that to johnny so

johnny now knows mark's mac address so

we can send him a ping if i open that

frame up that's sent to the switch we

see the source is johnny's mac address

and the destination is

mark's mac address and if we click

continue it'll go to mark

mark will respond bam johnny gets it if

we check our terminal real quick

our command prompt it's happening if you

click real time it will just

continue so that's what happens when

someone's on the same network johnny

knows

that mark is on the same ip network but

what happens when johnny tries to get to

the network

coffee company let's see let's have him

ping it so we'll open up johnny once

more here

go to his command prompt and we'll ping

the ip address of my copy server so ping

23.227.38.65

let's go to our simulation so we can

watch this in real time

and let's hit enter boom okay so far so

good we have an arp frame that johnny's

getting ready to find out where

my coffee server lives maybe his mac

address let's open it up and see

click on that message and huh

do you notice anything weird here you

know what pause the video right now and

see if you notice anything that might be

strange

unpause okay here we go so just like

before johnny's sending a frame to a

broadcast address to say hey

who's got this ip address but he's not

asking about the ip address of my coffee

server

no no look here this is a source ip this

is his ip address

but he's trying to discover the ip

address or the mac address rather of

10.1.1.1

why because when he tried to find out

mark's mac address

this right here was 10.1.1.2

that was the destination why is this

different because johnny knows

johnny knows the coffee server is not on

his network

so he's not even gonna try to connect to

that coffee server

on layer two he's not gonna try to

discover his mac address he gives up

immediately watch what happens let's

step forward in time so johnny sends

this arp

message saying anyone out there are you

10.1.1.1 and the switch will send this

out

and as we step forward in time stepping

forward stepping forward stepping

forward

no one responds johnny keeps sending out

arp request does anybody have 10.1.1.1

does anybody have it and no one responds

who is 10.1.1.1 and why is johnny trying

to talk to him

let's find out it comes down to how we

configure johnny let's open up johnny

real quick

go to his config and the answer is right

here there it is

10.1.1.1 is his gateway gateway is

another word

in the networking world we use for

router as i said before johnny knows

that

people in his network are 10.1.1.0

through 10.1.1

johnny knows that if anyone has an ip

address in that range they're in his

network

they're in his neighborhood he can just

walk over and talk to him find out where

they are like yeah i know bill he just

lives two doors down i can walk over

there and talk to him

but if johnny tries to reach an ip

address outside that range

he knows it's not in his network and

he's gonna need some help he needs help

connecting to a different network

and that's where a router comes in so

let's throw the router back in there and

have some fun this is gonna be so cool

watch this now before we move on it's

important for you to know that i did

pre-configure this router not a crazy

amount of configuration but i did add

some configuration to make this work

for the most part switches work out of

the box no problem a router's a bit more

complicated because it has to know how

to

route between networks he's a router he

has the map of how to get to things i'll

show you what i mean check this out

we're going to have johnny here once

again try to peeing

networkchuck.coffee let's open up his

command prompt so i'll go to his

command prompt we'll go back to our

simulation we're in simulation mode

bullet time mode

and let's watch some crazy router magic

happen so we're gonna ping

the coffee server and go now same story

as before johnny knows that this is not

on his network he knows that bob lives

in another state and he can't just walk

over there he's like i gotta use my

gateway i gotta find my router and his

router will be connected to his network

watch what happens a step forward in

time the art message is sent out to the

broadcast

and keep in mind the same reason that

johnny's sending an art packet for the

router

is the same reason he had to send one

for mark he doesn't know the mac address

for 10.1.1.1

and he must know the mac address so the

switch will know how to get his stuff to

the router the switch sends it out to

everyone and lisa

denney mark this server right here which

i can talk about here in a moment

they're all like yeah that's not me but

then the router's like

that's me i'm 10.1.1.1 and he sends a

reply back saying yep that

is me the switch tells johnny hey this

guy lives here that's his address

walk on over so johnny does if we open

up that frame that just arrived at the

switch

we can see the source is indeed johnny

and the destination is

the router and then we'll step forward

in time it arrives at the router and

then we have something blinking and

flashing let me let me zoom in on that

this is so cool what's happening right

here let's open up the freaking out guy

right now

isn't that working fun oh my gosh okay

here's what's happening now what are the

router receive right here well if you

just look at layer one and layer two we

know that he received this frame on his

gigabit zero zero interface as this

little message says right here but

because we have layer three involved

we know that to be called a packet

remember that's what routers do man they

are all about layer three they are layer

three devices they can handle the ip

addresses

that's the language they speak so this

is what the router received notice it's

from

the mac address that belongs to johnny

right here

and it's to his interface but then look

what he's sending out and notice what's

missing

layer two now according to his layer

three map he knows that two two

three.227.38.65

is that way but that's layer three he

doesn't know where he lives at layer two

and because he's about to send this

frame to the switch he doesn't know how

to tell the switch how to get to him and

that's important and that's the reason

we have this freak out message like i i

don't i don't know

what his layer two address is so how

does the router find out

well how did johnny find out an art

message he says

hey where is 23 blah blah and he

broadcast that out

watch right next to the freakout message

we have the art message right here

from the router to the broadcast and

we're looking for anyone that has this

ip address

anybody got this anybody out there and

let's step forward in time and watch

this happen

so he sends the art message to the

switch the switch broadcast it out and

because the server is the only one that

is on the network he receives it the

server's like

hey that's my name that's me i'm over

here so he sends the response to the

switch

the switch is like yeah i know where

this guy is hey router i found him i

know that everyone knows where everyone

is johnny's ready to send his message so

if you open up johnny's message over

here

i want you to pick up on this in the

layer 3 header johnny has his ip address

as the source

the coffee server as the destination but

on the layer 2 level

we have his mac address as the source

and then the destination is the mac

address of the router

so layer 3 right here is directions for

the router saying hey router this is

where i want my message to go

and then layer 2 right here is

directions for the switch saying hey

switch this is where i want my frame to

go it's going to go to the router and

the router will take care of the rest

let's watch it happen step forward in

time the switch receives it if we open

that message up we can see it's only

layer 2 because the switch can only see

layer 2.

it's going straight to the router so we

send it to the router this is so cool

isn't it

it's amazing let's open up that router's

message and look at that

this is the message he received so layer

two it's from mark's mac address

to his mac address layer three it's from

mark's ip address

to networkchuck.coffee's ip address and

now for the outbound message because he

learned where the coffee server's mac

address is

he can send it out so here's the layer

three and then for the switch he's got

the directions right here

from his mac address to the coffee

server's mac address which

ended in one ac7 if you look at that yet

it matches up right there let's watch it

happen

boom the switch sends it out and the

coffee server got it and then the coffee

server

replies and sends it back the router

sends it through the switch gets it

and then johnny gets it isn't that

amazing and this happens millions of

times every day across networks across

the world

isn't that just crazy now i want to show

you one more thing it's kind of a sneak

preview to what we're going to be

talking about later but obviously

johnny he wants to order some coffee

from networkchuck.coffee but you can't

order coffee

by just pinging the web server you have

to visit the website and we can do that

let's have johnny do that right now so

i'm going to reset everything and we'll

get this thing ready this is going to be

amazing

don't let this overwhelm you we will go

over the details of how this works

later on but i just want to i just want

to show you because it's so neat

i i can't help myself so we're still in

simulation mode let's open up johnny

real quick

and instead of going to the command

prompt we can go to his web browser so

i'll click on web browser right there

and the website is network chuck

dot coffee now the main difference here

is that we're not using an ip address

at least to start with it's this

friendly name that we know we normally

use like facebook.com youtube.com but

how does that work

we know the switch loves mac addresses

and that's what he talks that's the

language he talks layer two

the router loves layer three ip

addresses who deals with names like this

well the short answer is no one johnny

must know the ip address

or rather johnny's computer must know

the ip address so when he types this

networkcheck.coffee url in there's got

to be some way that his computer can

find out what the real ip address is

which we just pinged

moments earlier that's called dns and

that's what our dns server here is for

let's watch it happen

i'll click go and boom oh whoops i

forgot to configure the dns server if i

go to config

under his uh default gateway we have dns

server which stands for domain name

service

and i'll put in the ip address of our

dns server up there 10.1.1.50

this guy right here so let's go back to

our our web browser and try it again

go and here we go all over again we have

another art packet because johnny

needs to get the information on

networkchuck.coffee he needs to learn

the ip address and he knows that this

server the dns server

knows the information that's 10.1.1.50

and that's his first job so he has to go

through the process again of

learning the mac address of the dns

server let's walk through that now

stepping forward in time sends an art

message the switch will broadcast that

to everyone

the dns server responds because that's

his ip address and he's like here's my

mac address that's me

the switch sends that to johnny and

johnny's like yes

so now johnny can send his dns query to

find out where networkchuck.coffee is

what's the ip address

so he'll get that message ready so we

sends it out it goes to the dns server

we'll take a quick little peek inside

that real quick and we'll open that up

and a lot of stuff going on there

that's the other layers we'll talk about

don't worry about that but essentially

the server's like yeah i know where that

is here you go johnny here's the

information so he sends it to the switch

the switch sends it to johnny johnny

learns where this is

let's open it up real quick i'll show

you let's open that up and we'll go to

the inbound

pdu details again don't worry about that

just yet

we'll scroll down all the way to the

bottom we can see that the information

the dns

answer is right here the name

networkcheck.coffee and then here's the

response

the ip address of our server so we'll

step forward in time

johnny will send his http get request

we'll cover more on that later

to the router to the switch now what you

might be noticing is that we didn't go

through the whole process of learning

the mac address of the router and the

router learned the mac address of the

the coffee server no no it remembered it

puts that in its cache

and it stores it so we don't have to do

it all over again now i will eventually

forget that information so it can

relearn it

but again more on that later so let's

step forward in time it goes to the

server

the server gets it responds back and you

know what i'm going to switch to real

time

let's open up our web page and there it

is you need to drink coffee right now

and there's our website as you can tell

it's been expertly designed and by the

way that's real if you want to buy my

coffee network

coffee it's delicious that's what i'm

drinking right now

it's real now i've got this lab and a

link below if you didn't follow along

with me throughout this go and open it

now and try it for yourself

it's really cool to walk through all

this and just see it happen like this is

how the internet works

this is what what happens when you get

on your computer and you go to

youtube.com

this process happens this right here is

your home router

you're johnny now the real internet

isn't this simple

right the the real internet is a is

going to be like this router connected

to

another router connected to another

router connected to another router

and then eventually getting to my coffee

website as we covered in the first video

but the process is still the same the

router is connecting

these two separate networks i remember

when i say network i'm referring to the

ip addresses layer 3.

these guys over here have a different

group of ip addresses than these guys

over here your home network will be a

different group of ip addresses from

the rest of the world and that's why you

need a router to connect to the internet

and inside of this router's brain if you

pop him open he has a map

to other networks and to the internet

like you know let's take a look

let's have you enter another cisco cli

command right now let's pop it open

let's do this

i'm going to click on the router we'll

jump on over to his cli tab

we'll hit enter and then type in enable

to see his map

his map of ip addresses and where to

reach different networks we'll do

show ip route

this is a command that network engineers

use all the time you're already doing

networking right now

let's hit enter and boom i'm going to

expand this out a little bit here

and this might look a little

overwhelming but here's all it's saying

the group of ip addresses that johnny

belongs to

is right here 10.1.1.0 24.

that's just a shorthand way referring to

10.1.1.0

through 255. and in the router's map

he knows that it's actually directly

connected to his interface gigabit

ethernet one

or i'm sorry zero zero and the same goes

for my coffee network over here there's

the network and again it's a shorthand

way of saying 23.227.38.03255. and

that's actually directly connected to

gigabit 01. so when johnny said hey i

want some coffee i want to order it

right now

and he sent his packet to the router

saying here it is i want to go to this

guy the router's like oh well let me

check my map

oh there it is there's the network it's

actually connected to my gigabit zero

one interface i'm gonna send it out that

interface

that's how the router knew now this is

very simplistic routing routing gets

crazy like if you were to look at a

router on the internet

you know let me show you real quick this

is actually one of the routers on the

internet check this out

i'll enter the command show bgp which is

a routing protocol

we'll learn more about those later ipv4

unicast

and let's see what we got and all of

these are routes to different

networks on the internet like i can keep

going i mean look at this this is insane

this is this router's map this router is

probably huge very expensive

router but this is an example of a how

big the internet is and b

what a router can do why it's so

powerful all right we'll never reach the

end of this i'm just going to stop

and that was episode two now i changed

it from days to episodes

makes more sense for me if you have any

comments or questions let me know below

i would love to hear your feedback on

this

if you need help don't be shy ask some

questions below either myself or some

others will join in and help you out

or hey join my discord we've got so many

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to help out

with really any questions you have and

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alright that's all i've got episode two

done i'll see you in episode three

[Music]