What is a SWITCH? // FREE CCNA // Day 1
Summary
TLDRThis script kicks off a free CCNA course with a special thanks to Boson Software for sponsorship. It delves into the fundamentals of network switches, contrasting them with hubs and highlighting the switch's intelligence in managing data traffic efficiently. The video guides viewers through hands-on experience with Cisco Packet Tracer, exploring the concept of MAC addresses, the CAM table, and the basics of networking layers. It concludes with a quiz from Boson's renowned CCNA practice exam, emphasizing the importance of understanding switches for networking professionals.
Takeaways
- π The video is part of a free CCNA course sponsored by Boson Software, who provide CCNA and CCNP labs and practice exams.
- π The course begins by exploring the function and importance of network switches, emphasizing their role in connecting devices and facilitating communication.
- 𧩠Cisco Packet Tracer is introduced as a tool for analyzing network traffic and learning about the operation of switches and hubs.
- π The script explains the difference between switches and hubs, highlighting the intelligence of switches versus the broadcast nature of hubs.
- π‘ It's revealed that switches operate at Layer 2 (data link layer) of the OSI model, utilizing MAC addresses to manage network traffic efficiently.
- π₯οΈ The video demonstrates the use of Cisco CLI commands, starting with 'show mac address-table', to inspect a switch's content addressable memory (CAM) table.
- π MAC addresses, also known as Layer 2 addresses, are unique identifiers for network devices, used by switches to forward messages to the correct port.
- πΆ The script touches on wireless access points, noting their similarity to hubs in terms of broadcasting signals to all devices, unlike the direct communication of switches.
- π The disadvantages of hubs, such as traffic jams and collisions, are contrasted with the efficiency and reduced collision domain of switches.
- π The video includes a quiz with questions from Boson XM, a renowned source for CCNA practice exams, to test understanding of switch operations and the CAM table.
- π The importance of preferring wired Ethernet connections over wireless for reliability and performance in network communication is emphasized.
Q & A
What is the main focus of the first day of the CCNA course?
-The main focus of the first day of the CCNA course is to introduce the concept of a switch, how it works, and its importance in networking.
Who is the official sponsor of the CCNA course mentioned in the script?
-Boson Software is the official sponsor of the CCNA course.
What tool is recommended for analyzing frames and packets going across the network?
-Cisco Packet Tracer is the tool recommended for analyzing frames and packets going across the network.
What is the difference between a switch and a hub in terms of functionality?
-A switch is a smart device that learns and forwards messages only to the intended recipient based on MAC addresses, whereas a hub is a dumb device that broadcasts messages to all connected devices.
What is the purpose of the Cisco CLI command 'show mac address-table'?
-The 'show mac address-table' command is used to display the switch's CAM table, which shows the MAC address to switch port assignments.
Why are switches considered more secure than hubs in a network?
-Switches are considered more secure than hubs because they only send messages to the intended recipient's port, preventing unauthorized access to the data being transmitted.
What does the acronym 'CCNA' stand for?
-CCNA stands for Cisco Certified Network Associate.
What is the significance of a MAC address in the context of a switch?
-A MAC address is a unique identifier for network devices. Switches use MAC addresses to learn which devices are connected to which ports and to forward frames to the correct destination.
How does the script describe the process of sending a message between two devices using a switch?
-The script describes the process as sending a message (frame) from one device to the switch, which then forwards the message to the intended recipient based on the MAC address stored in its CAM table.
What is the difference between a frame and a packet in the context of networking layers?
-In the context of networking layers, a frame is a unit of data specific to Layer 2 (the Data Link Layer), while a packet is a unit of data that includes Layer 3 (the Network Layer) information, such as IP addresses.
Why are wired connections often preferred over wireless connections in certain scenarios?
-Wired connections are often preferred over wireless connections because they can provide a more secure and stable connection, avoiding the issues of broadcast to multiple devices and potential traffic jams or collisions that can occur in wireless networks.
How does the script introduce the concept of layers in the OSI model?
-The script introduces the concept of layers in the OSI model by discussing Layer 1 (the Physical Layer), which deals with the physical aspects of networking like electrical signals and cables, and Layer 2 (the Data Link Layer), which involves MAC addresses and frame forwarding by switches.
Outlines
π Introduction to CCNA and Networking Basics
The video begins with an introduction to a free CCNA course, sponsored by Boson Software. The speaker emphasizes the importance of switches in networking, explaining their function and the excitement of learning through hands-on labs using Cisco Packet Tracer. The concept of 'labbing' is introduced, and the audience is encouraged to explore the depths of networking, likening it to taking a red pill from the Matrix. The summary of a previous video on network components is provided, and the video promises a deeper dive into the subject matter.
π Understanding Ethernet Cables and Switches
This paragraph delves into the physical aspects of networking, focusing on Ethernet cables and switches. It explains how switches enable computers to communicate using electrical signals through these cables. The speaker uses an analogy of sending a text to illustrate the concept of data transmission. Different switch sizes are introduced, with an 8-port and a 48-port switch being highlighted. The importance of understanding the inner workings of a switch is emphasized, and viewers are encouraged to download Cisco Packet Tracer for a practical demonstration.
π‘ Transition from Hubs to Switches in Networking
The speaker contrasts the functionality of hubs and switches, describing hubs as the predecessor to switches. Hubs are characterized as 'dumb' and less efficient, broadcasting signals to all connected devices regardless of the intended recipient. The audience is invited to experience the limitations of hubs firsthand using Cisco Packet Tracer. The video then demonstrates the superior intelligence of switches, which can direct data to specific devices, improving efficiency and security.
π± MAC Addresses and Layer 2 Communication
This section introduces the concept of MAC addresses, also known as Layer 2 addresses, which are unique identifiers for devices connected to a network. The speaker explains that switches use MAC addresses to learn and remember the location of devices, storing this information in a CAM table. The difference between Layer 1 (physical layer) and Layer 2 (data link layer) is discussed, with Layer 2 being where MAC addresses play a crucial role in communication.
πΆ Comparing Wired and Wireless Networking
The video touches on wireless access points, comparing their behavior to that of hubs rather than switches. Wireless access points are shown to broadcast signals to all devices, similar to hubs, which can lead to traffic jams and collisions. The speaker advises preferring wired connections for their reliability and efficiency. The limitations of wireless networking are acknowledged, and the benefits of Ethernet cables are highlighted.
π Quiz and Conclusion of CCNA Day One
The video concludes with a quiz based on the material covered, sourced from Boson's renowned CCNA practice exams. The questions focus on understanding how switches use MAC addresses to populate their CAM tables and make forwarding decisions. The speaker reviews the correct answers and provides explanations to reinforce the learning. The video wraps up with a summary of the topics covered on 'CCNA Day One' and a teaser for upcoming videos on routers and the OSI model.
Mindmap
Keywords
π‘CCNA
π‘Boson Software
π‘Switch
π‘Cisco Packet Tracer
π‘Ethernet Cable
π‘MAC Address
π‘Layer 2
π‘Hub
π‘Wireless Access Point
π‘Packet
π‘CLI Command
Highlights
Introduction to a free CCNA course sponsored by Boson Software, offering the best CCNA and CCNP labs and practice exams.
Explanation of what a switch is and its fundamental role in connecting devices within a network.
The importance of Cisco Packet Tracer as a tool for analyzing network traffic and understanding how switches operate.
The concept of 'labbing' and its significance in the learning process of networking.
The introduction of the Cisco CLI command and its role in interacting with network devices.
A comparison between switches and hubs, highlighting the intelligence and efficiency of switches.
The demonstration of how a switch works using Cisco Packet Tracer to show the flow of data packets.
The difference between a hub's broadcast behavior and a switch's intelligent forwarding of data.
Understanding the function of the CAM table in a switch and its role in remembering device locations.
The distinction between MAC addresses and IP addresses in the context of layer 2 and layer 3 networking.
The process of how a switch learns and updates its CAM table with MAC addresses.
The difference in behavior between wired switches and wireless access points in terms of data transmission.
The impact of wireless networking on security and efficiency compared to wired connections.
The importance of Ethernet cables and the preference for wired connections over wireless for network reliability.
A quiz based on the material covered in the video, sourced from Boson's renowned CCNA practice exams.
The significance of the 'show mac address-table' command in understanding the switch's memory of device locations.
A summary of the key concepts covered in the video, including switches, MAC addresses, and the OSI model layers.
An invitation to follow for upcoming videos on routers and further exploration of the OSI model.
Acknowledgment of Boson Software's sponsorship and promotion of their lab and practice exam software.
Transcripts
this is day one 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 day one we're
not wasting any time
we're getting right into what is this
it's a switch how does it work
why is it amazing because it is amazing
and we'll even get a chance to lab what
does labing mean well you'll find out
we're going to use cisco packet tracer
to analyze frames and packets going
across the network and you're going to
get a chance to enter your first
cisco cli command let's get started
[Music]
in my last video we talked about what a
network is and we followed a call of
duty bullet when i shot it from my
computer
how it goes through my home network to
my brother's network and shoots his
character and we went high level like
router switch firewall access point what
are those things
but we didn't go too deep but now are
you ready we're gonna go just a little
bit deeper it's just like one of those
red pill blue pill situations from the
matrix
after this there is no turning back you
take the red pill
you stay in wonderland and i show you
how deep the rabbit hole goes
you take this pill there's no going back
we're going deep into the networking
rabbit hole
you're going to fall in love and never
look back okay i warned you you're still
watching this that means you want to
keep going
let's do this okay let's talk about
switches first what are they and what
are they doing and
here's one right now this is a switch
it's beautiful isn't it look at this
oh love it now if you watched our last
video you have a high level view of what
a switch is for
what's it doing well it's helping our
computers to connect to each other and
talk and hang out and chat
send data we connect using these
ethernet cables and we plug them into
our ports
oh love that sound here listen to this
up close
asmr version uh one of my favorite
sounds
so we connect one computer connects
another computer and assuming we have
computers on the other ends of these
they're talking they're having fun
they're playing games but what's really
going on inside of here
let's pop the hood let's take a look oh
by the way switches can come in many
different sizes like this is an 8 port
and this big boy
is a 48 port he's beautiful
[Music]
why do you need 48 ports well so you can
connect 48 different devices to each
other that's why now let's first look at
this guy the ethernet cable
all it is is a bunch of metal wires like
check it out
your computer communicates with the
other computers via electrical signals
and these electrical signals go down
these wires through the cable to the
switch and then it goes to the other
computer it's amazing it's just
electrical signals going in and out of
these ports it's
isn't that cool now switches are amazing
but for you to really appreciate how
amazing they are you need to look at
their predecessor the one that came
before them the hub
he's disgusting he's dumb he doesn't
have any smarts
the switch is smart the hub is not but
before we had switches
hubs are all we had and here's what they
did and why they're dumb now i want you
to actually see how dumb this is and
experience it for yourself so right now
what i want you to do is go download
cisco packet tracer i've got a link
below
sign up for a free account through
netacad and you'll be able to download
it what is this
it's a tool that lets you build and play
with networks and
so much more it's amazing so go download
and install that it's on windows
mac linux and once you install packet
tracer i've got another link below for a
pack a tracer file which is a lab i
built that we can play with right now so
go ahead and download that
and launch it do not get overwhelmed
with all the buttons and options here
i'll walk you through every step
right now if you zoom in right here i've
got two networks i got this one here
which is a switch
and my laptops if i scroll over i've got
another network and it's
not nearly as smart because i'm rocking
a hub now a hub and a switch
physically kind of look the same they
look like this they have ports where you
can plug ethernet cables into
but they're so so different actually we
can look at a hub right now let me click
on the physical button up here
i can click on my home city my corporate
office and then
jump into my wirelink wiring closet and
there it is so you can see switch it's
got ports hubs got ports okay
but why are they different how would you
like this if when you sent a text to
your friend
it didn't just go to your one friend it
went to all your friends
and then when your friend responded back
to you it only went to you but it went
to all your friends as well
that's stupid right like that i would
never use that texting platform that's
what a hub does
check this out and i want you to do this
with me so click on simulation down here
at the bottom right
this is what makes packet tracer so cool
we can analyze the network traffic
slowly as it goes through
the electrical wires it's oh it's
powerful anyways so don't touch that
leave it there i want you to click on
harry potter up here laptop harry
then click on desktop and then click on
command prompt this is very similar to a
windows command prompt it kind of is a
windows command prompt
and what we're going to do is we're
going to have mr harry here talk to ron
over here
through the hub we're going to send a
message that we use in networking all
the time called
a ping message what is that for we use
it to see if other computers or servers
are up
and can be reached kind of like this
ping reply
now you may have noticed i've got a
couple things right here layer two
address and layer three address now
what's an address
well if i wanted to send you a message i
might send it to your email address if i
want to send you a letter i might send
that to your
mailing address it's something unique to
you that allows me to send something to
you
data whatever and in the networking
world it's the same thing now what does
layer 2 and layer 3 mean
we'll cover that here in a bit but just
know that when i'm going to send a ping
message to ron i'm going to be looking
at his
layer 3 address that might look familiar
to you what is that
well that's an ip address you're
probably familiar with that right
harry knows that when he wants to talk
to ron that's his address that's his
phone number that's his mailing address
that's how he gets information to ron
his ip address so here we go we're about
to ping ron now please make sure you
have the simulation button checked not
real time you want simulation
here we go get your command prompt open
we're going to ping ron so i'll type in
ping and the ron's ip address 10.1.2
now watch what happens when i hit enter
boom
a little envelope popped up a little
message we're going to send to ron and
then notice over here we have a little
event timeline where that message is
popped up
we can see the play-by-play here as we
get more advanced and go deeper and
deeper into what's happening which
actually happen in the next video we can
click on these
and look at some hairy details like
what's happening
don't worry about that yet we'll get
into it but it's amazing so harry wrote
his letter he's ready to send it
and if we click on this little advanced
button right here it'll take a step
forward in time let's go ahead and do
that
click advanced boom let's do it one more
time
boom there it goes it's going across the
network electrical signals firing
so now the hub has the message in an
ideal world in a perfect world the hub's
like okay well this message is for ron
i'm going to send it to ron
but the hub's an idiot he's dumb watch
what happens
watch what happens click next and
why did you do that mr hob you sent the
message to everyone
harry's just trying to talk to his buddy
ron and now hermione knows and and
malfoy knows that's
that's bad right now watch what happens
next remember in a ping situation
harry's gonna send a ping
hey you there ron iran's gonna go yes
i'm here but watch this click next
ron does reply perfect but then watch
what the hub does the dummy hub
he since ron's replied out to everyone
why hub why well again the hub has no
smarts he's got no brain
his job is just to repeat that
electrical signal whenever your computer
sends down this wire
the hub is going to go and send out to
everyone this is how we did things for a
long time
now notice that over here harry potter's
got a green check mark going yes yes yes
that message is for me yes yes yes
but then down here malfoy and hermione
have this x
which means that most the time in a hub
environment if a computer got a message
that wasn't
meant for them it would just ignore it
but
you know that's if you're a good person
if you're a hacker like i'm learning
hacking right now if you get a message
like that if you're
able to see everyone's traffic you're
like yes yes give me more i'm gonna hack
all you guys
not a very safe and secure environment
you don't want to text your buddy
something secret and all of a sudden all
your friends know the secret
but now let's look at the switch he
fixes everything go ahead and click on
reset simulation
you can close out harry potter there and
let's scroll on over to the better
environment
the switch environment now here the
switch has the same
goal as the hub just to connect these
computers together so they can talk so
they're doing the same job
just one's really really good at it so
over here let's walk through the same
situation johnny right here is gonna
ping
mark oh hi mark and we'll see what
happens and i'll explain how it happens
here in a moment so go ahead and click
on johnny click on the desktop tab and
then jump into your command prompt we're
going to type
in ping and then mark's ip address right
here is 10.1.1.2
we're going to hit enter and bam
johnny's got a message ready for mark
let's click on next and see what happens
next
next okay there it goes the switch has
it what's it gonna do
boom so much better only mark got it and
then when mark responds
it only goes to johnny that's how it's
supposed to work thank you mr switch
and if you look back at our command
prompt you can see that we sent a ping
message
and then we got a reply from mark from
the ip address
everything's good mark's alive he's like
hey yeah yeah johnny i'm here and if we
click on real time it'll just complete
it like it normally should
bam bam bam really fast because these
electrical signals are going really
really fast down
these wires but that's what's cool about
this packet tracer we can slow down time
bullet time and watch it happen
okay we're about to go deeper we're
about to learn more about how this guy
does things
are you ready let's take a deeper look
the switch can do all this magic because
it has a brain
a brain that can remember things like
hey on my port fa02
that's where johnny lives and on my port
fa01 that's where mark lives
and the same thing goes for denny and
lisa and anyone else who connects to the
switch
he'll remember where they are so when
you send a message he'll go oh well i
know exactly where johnny is he's over
here
port fa02 he stores that information in
something called
the cam table which stands for content
addressable memory
don't worry about that too much right
now we'll cover a lot of that later now
the switch doesn't know
johnny as johnny the switch knows johnny
as
00d097528936
that's how the switch knows johnny has a
layer 2 address that's how the switch
knows mark he doesn't know mark's name
but he doesn't know zero zero e0b0590897
love that guy what are these things
that's called a mac address
often referred to as a layer two address
every single device that you connect to
the internet
has a mac address every one of them like
go ahead and look get your laptop out
look for it like on this phone here that
i would connect to the switch
look right here there's my phone's mac
address right there
it's often referred to as the burned in
address because this address
should never change that's how your
device is identified it's unique
identifier so when i connect my
phone to this switch and my phone tries
to talk to somebody
boom the switch learns hey that phone
which
that phone's name is 9c57803844a
he lives on port 1. so if anybody wants
to talk to him it's gonna be part one
now we'll cover more about layers here
in a moment i'm kind of building up to
that
but this right here doing this and that
wonderful beautiful sound
yes that's this is layer one anything
physical
the the electrical wires the metal wire
that send electrical signals down into
the switch that's layer one
so layer one electrical signals firing
at light speed down ethernet cable
physical
and then we get to our switch and now
we're thinking about layer two
that's where our layer two address comes
in that's where the mac address comes in
layer two is often referred to as the
data link layer but we won't cover too
much on that right now
i have to stop i don't wanna give you
too much right now now you may be
wondering why isn't the switch just
using the
layer three address like what we used
when we pinged 10.1.1.2
why isn't the switch no marked by that
number well the simple answer is that
the switch can't even see that number it
has no idea what it is
you see the switch is a layer 2 device
and doesn't know anything about layer 3
or ip addresses or anything that's why
we're dealing with mac addresses right
now now watch this let's get back to our
packet tracer we're going to do a couple
things here real quick let's click on
simulation mode once more
and let's open up mark we'll go to his
desktop go to his command prompt
and we're going to ping lisa down here
so we'll do ping
10.1.1.5 and hit
enter the message was built now go and
click the forward message real quick
and i want you to click on this this
message right here we have click on it
now as you can see we have seven layers
we're going to be talking about here
very soon but don't don't think about
anything above layer three right now
don't think about that but notice
this message we're sending to the switch
notice what's not there
layer three is missing it's just layer
two
because that's all the switch
understands and also notice the two and
from so right here we have the from
which is the mac address of
mark over here and then the two is to
lisa's mac address down here and if we
go ahead and step forward in time
boom the switch receives it if we click
on that message again we see that switch
receives it
and he knows exactly where to send it
because he remembers where lisa is
and then if we click on that button bam
it goes to lisa now i'm not sure if i
want to show you this yet
yeah let's go ahead and do it so click
on that envelope right there the message
that just arrived to lisa
you can see here that instead of just
having layer one and layer two we now
have layer three
involved because that's a layer that
mark and lisa are talking on layer three
you see we
pinged from mark's ip address 10.1.1.2
to lisa's ip address of 10.1.1.5
and then lisa is sending out a message
see out
to mark at 10.1.1.2 from herself
10.1.1.5 and then we step forward in
time once more
boom we see this message go to the
switch but then if we open that message
oh layer three is gone again it's just
layer two because that's all the switch
cares about is layer two
and that's how he knows where things are
that's where devices are based on their
mac address now go and click on real
time let that finish out and we're gonna
jump into the switch's command line
interface and this might be your first
cisco command kind of exciting so let's
let's open it up
what we're going to do is we're going to
look inside the switch's brain so go and
click on him
and jump to the cli tab this is a whole
new world for you yes okay
now hit enter then type in enable and
hit enter
now you should have a hashtag sign right
there next to your switch here's a
command i want you to enter
show mac dash address dash
table we're looking inside the switch's
brain and looking at his cam table where
he keeps the mac addresses and how they
are assigned to the ports
because mark and lisa just talked the
switch knows that mark
which is referred to as blah blah blah
mac address lives fa01 and then lisa
lives at fa03 and then if we go to denny
over here
and we go to desktop and command prompt
and we try to ping johnny 10.1.1.3
it's going to go through it's being
successful awesome if we jump back into
the switch and hit the up arrow to enter
the same command
hit enter well now the switch knows
where everyone is he knows where johnny
is where denny is or mark and lisa
he learned it stored it in his brain and
now whenever someone sends a message he
goes
i know exactly where they are boom right
there the hub just doesn't do that and
that's the job of the switch
he learns where everyone is by learning
their mac address they're burned in
address
and stores that in his brain is cam
table and marks where they are so
whenever he receives a message
he can forward those messages to the
appropriate people
and not to anyone else that shouldn't
hear about it now when we're talking
about layer two
this message right here is referred to
as a frame all the messages going
through this switch right here are
frames
boom boom boom frames just going around
like crazy because it's layer two when
you think layer two think switch think
frames
switch frames layer two switch frames
layer two is it working is it going in
there but then when the message goes to
lisa and we're talking about ip
addresses in layer three
do you know what it becomes this message
is now a packet
now just so you know when you're talking
to network engineers and other folks
they might refer to layer two messages
the frames they might call those packets
as well
we just get in the habit of it if it's
going across the network and it's going
to people and it's a message
we often just refer to it as packet it
just happens but technically
it's frames layer 2 frames switch layer
2 frames switch
okay now we're gonna talk a little bit
about wireless um here's a
wireless access point little baby cisco
one here's a bigger
cisco one the reason i wanna talk about
them now along with switches is because
they're basically doing the same job as
a switch
but what's funny what's funny is they're
more like a hub
than a switch they're kind of dumb i
mean they're amazing but they're kind of
dumb like a hub let me show you
looking back at packet tracer if i
scroll down just a little bit you can
see i have a little wireless network
here let me add the uh
ip addresses here real quick now what i
want you to do real quick is down here
at the bottom
click on the lightning bolt or harry
potter esque and then click on the
lightning bolt again this is a
connection it's like plugging an
ethernet cable and we're going to plug
it into the
access point here and then plug it into
our switch we talked a little bit about
wireless in the first video but it's
just an extension of the switch so it
connects to the switch with an ethernet
cable and then it connects all the other
devices via
wireless which we know to be airwaves or
radio waves
so most of our devices like our phones
and everything else connect to this
access point
which is connected to a switch now even
though this access point is connected to
a switch
he's actually more like a hub and it's
all about these connections right here
let me show you real quick
i'm gonna have mr denny here i'm gonna
click on denny and launch his laptop
we're going to go into his desktop and
go to his command prompt
and we're going to ping let's say the
first tablet down here 10.1.1.11 so i'll
do ping
10.1.1.11. oh and i forgot to go into
simulation mode let's go to simulation
mode down here
bring denny back up and boom
so as you can see denny's got his packet
ready and he sends
this frame to the switch now if we open
up that frame
what do we see well we see that the
source is indeed
denny over here based on his mac address
and then the destination
well what is that matching let me scroll
down here we can see yeah it does match
the first tablet here so the switch
knows that he lives on this port
connected to the access point but it's
what the access point does with it
that's so
stupid but it's just how wireless is
right now let's skip forward in time
the access point has it now but now
let's see what happens
click next boom and once more
boom
the message was sent to everyone like a
hub now we'll cover
wireless in more detail here later in
this course but just know for now
that's why people tell you plug into an
ethernet cable at all cost if you can
because a wireless
connection is more like a hub and the
fact that all the messages are going to
each device isn't the worst part with
hubs it's just a traffic jam collisions
all the time
which is why switches are great and
we'll cover more on that later but yeah
always prefer ethernet cable a hardline
connection to a wireless connection if
you can
now later versions of wi-fi like wi-fi 6
do help out with this i actually made a
video on wi-fi sticks that you can check
out up there
and then as we step forward a time when
the first tablet sends here's a reply
back
the access point will then send it to
the switch and then the switch like it's
supposed to we'll just send that to
denny
but then we had the same process happen
again when denny does send another ping
hey
hey first tablet are you there the
access point will still broadcast that
doubt out to everyone
all right hope you have your coffee
ready time for a quiz time to test your
knowledge and what we just
covered in this video the questions i'm
about to ask you are not easy
i pulled them from boson xm the best
ccna
practice exam you can find they are
world renowned and they are sponsoring
this video so check out the link below
for that exam
anyways let's see what you know question
number one
which of the following addresses will a
switch use to populate
the cam table select the best answer
if your answer was b source ip address
you are wrong because the answer is in
fact
d source mac address remember switches
layer 2 mac address switches layer 2 mac
address
let's select our answer and get the deep
down dive from boson
so right off the bat because we know
we're talking about a switch in the cam
table we can mark out
a and b because those are talking about
ip addresses and the switch doesn't know
anything about ip addresses but what
we're talking about now is mac addresses
now it could have been source or
destination
a switch will learn a mac address and
add it to its cam table
when a device sends a frame
to that port and in that frame the
source mac address will be
this guy's mac address so that makes
sense destination would be
who he's sending that frame to which
might be a person over here and you
wouldn't want to add this guy's mac
address to
this guy's port confusion it wouldn't
work if you got that right that's
amazing
you're just a little bit closer to
passing your ccna next question
which of the following addresses will a
switch use to make forwarding
decisions select the best answer
[Music]
if your answer was destination mac
address then you are absolutely
correct let's select the answer and see
if boson
thinks i'm right here is boson's
wonderful explanation i encourage you to
pause the video and read that but
looking at the question it's talking
about
a switch making forwarding decisions
well we can automatically say you know
what
source ip addresses out destination ip
address is out because again switches
don't know anything about ip addresses
now when a switch
receives a frame from a device this
frame will have a source mac
address let's just say zero zero zero
one and a destination
zero zero zero two the source is coming
from this guy
that's his mac address he's trying to
send it to the destination mac address
this guy who is probably over here and
this question explanation is perfect
because it piggybacks off the previous
question
the switch will not use a source mac
address to make forwarding decisions
however it will use it to
populate the cam table again if you got
that right congrats you are even closer
to getting your ccna and if you didn't
it's fine
go back and watch the video learning is
a process it's a day by day thing
adding to your knowledge you'll get
there trust me didn't i tell you
switches are amazing and we i know i
keep saying this
have just scratched the surface and in
this video we covered some ground on how
switches work
you even got to work in packet tracer
and watch packets and frames
go across the network you may have even
issued your first cisco
cli command which is amazing write that
down today was your first command
show mac address table you looked inside
the switch's brain inside his cam table
to see the mac address to
switch port assignment that's huge and
guys that's about it we just covered day
one switches
in the coming videos we'll be talking
about routers and we'll be talking about
the other layers
of the osi model which we kind of talked
about layers one two and three today
we'll cover the rest soon and you're
gonna love it trust me if you like this
stuff you will
love love that stuff and again huge
massive shout out to bozon software for
sponsoring
this ccna series they're making it free
so i encourage you go check them out
they have
amazing labbing software so what i
showed you today was cisco packet tracer
it's great for demonstrating to you how
a network works
boson netsim is a great lab software
that will
allow you to go through labs and once we
get deeper into like cisco command line
stuff
where it gets pretty pretty
sophisticated pretty complex
they have fantastic labs that walk you
through things they'll grade you on how
you do
and they'll even explain everything it's
it's awesome and then of course the
practice exam questions i showed you
today
that's from their practice exam and ask
around their exams are
golden if you can pass their exams uh
you can probably pass the ccna many
people say
bosons is actually harder than the real
ccna
so links below for that again they have
their summer sale it's 25
off if you have any questions or
comments please let me know below and if
you like this video
like it hit that subscribe button and
hit that bell notification
icon to be notified when i post stuff
this was ccna
day one see you on day two
[Music]
you
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