Free CCNA | Network Devices | Day 1 | CCNA 200-301 Complete Course
Summary
TLDRThis video script introduces a comprehensive CCNA (Cisco Certified Network Associate) course, designed to prepare students for the 200-301 exam. It covers network devices, clients, servers, switches, routers, firewalls, and their roles in a network. The instructor explains the fundamentals of computer networking, including how nodes communicate and share resources. The script aims to provide foundational knowledge upon which future lessons will build, offering supplementary materials like quizzes, flashcards, and practice labs using Packet Tracer software. With a clear and engaging approach, the video promises to equip learners with the necessary skills to pass the CCNA exam.
Takeaways
- 👋 Introduction to a CCNA (Cisco Certified Network Associate) course covering network devices, connections, and concepts to pass the CCNA 200-301 exam.
- 🧑💻 Clients (PCs, laptops, smartphones) are devices that access services provided by servers (computers, websites, phones).
- 🔌 Switches are used to connect devices within a Local Area Network (LAN) and allow communication between them.
- 🌐 Routers are used to connect LANs and provide connectivity between networks and the internet.
- 🛡️ Firewalls control network traffic, allowing or denying access based on configured security rules to protect the network.
- 🔄 Servers and clients can switch roles depending on the situation - a device can act as a server or client.
- ☁️ The internet is represented by a cloud symbol in network diagrams when specific details are not necessary.
- 💻 Host-based firewalls are software firewalls installed on individual computers, providing an extra layer of security.
- ⚡ Next-generation firewalls combine traditional firewall features with advanced filtering and security capabilities.
- 📚 The course provides supplementary materials like quizzes, flashcards, and practice labs to reinforce learning.
Q & A
What is the main goal of this CCNA course?
-The main goal of this CCNA course is to provide a comprehensive learning experience, covering all the topics required to pass the CCNA 200-301 exam, while also offering additional information to improve the overall understanding of computer networks.
What are the different types of supplementary materials provided in this course?
-The course provides three types of supplementary materials: end-of-video quizzes, pre-made flashcards using Anki software, and practice labs using Cisco's Packet Tracer network simulation software.
What is the primary function of a router in a network?
-The primary function of a router is to provide connectivity between different networks or LANs (Local Area Networks) and to forward network traffic over the Internet.
What is the role of a switch in a network?
-A switch is used to provide connectivity and forward traffic within a single LAN (Local Area Network). It has multiple ports to connect various end hosts, such as PCs, servers, and printers.
What is the purpose of a firewall in a network?
-A firewall is a network security device that monitors and controls network traffic entering and exiting a network based on configured rules. Its purpose is to protect the internal network from unauthorized access and potential attacks.
What is the difference between a network firewall and a host-based firewall?
-A network firewall is a hardware device that filters traffic between networks, while a host-based firewall is a software application that filters traffic entering and exiting a specific host machine, such as a PC.
What is the significance of the term 'next-generation firewall'?
-A next-generation firewall combines traditional firewall features with more advanced filtering capabilities and functionalities, such as intrusion prevention systems (IPS).
What is the role of a server in a network?
-A server is a device that provides functions or services for clients. It can be a dedicated server hardware or any device (e.g., a PC or a smartphone) that serves data or resources to other devices (clients) on the network.
What is the difference between a client and a server in a network?
-A client is a device that accesses services made available by a server, while a server is a device that provides functions or services for clients.
What is the significance of the 'cloud' symbol in network diagrams?
-In network diagrams, a cloud symbol is often used to represent the Internet or any situation where the details of that part of the network are not necessary to show.
Outlines
🎓 CCNA Course Introduction and Network Basics
This paragraph introduces the CCNA (Cisco Certified Network Associate) course, covering its objectives, structure, and target audience. It explains that the course aims to provide comprehensive training for passing the CCNA 200-301 exam, including lectures, quizzes, flashcards, labs, and practice exams. The paragraph also defines a network as a system that allows nodes (devices) to share resources, and introduces various network nodes such as routers, switches, firewalls, servers, and clients.
🖥️ Clients, Servers, and Network Communication
This paragraph delves into the concepts of clients and servers, explaining their roles and functions in a network. It provides examples of client-server interactions, such as a PC requesting a file from another PC, accessing a website from a server, or receiving data from a friend's device. The paragraph emphasizes that the same device can act as a client or a server depending on the context.
🌐 LANs, Switches, and Routers
This paragraph introduces Local Area Networks (LANs) and explains how switches are used to connect devices within a LAN. It also discusses the role of routers in providing connectivity between LANs and the Internet. The paragraph highlights the characteristics of switches, such as having multiple ports for connecting end hosts, and routers, which have fewer ports and are designed for inter-network communication.
🛡️ Firewalls and Network Security
This paragraph focuses on network security and the importance of firewalls. It explains that firewalls monitor and control network traffic based on configured rules, protecting the internal network from external threats. The paragraph introduces different types of firewalls, such as Cisco's ASA (Adaptive Security Appliance) and Firepower series, and discusses the concept of next-generation firewalls with advanced filtering capabilities. It also briefly touches on host-based firewalls installed on individual devices.
🧠 Review and Practice Materials
This paragraph summarizes the supplementary materials available for reinforcing the knowledge gained in the lecture. It mentions end-of-video quizzes, flashcards created using the Anki software, and practice labs using Cisco's Packet Tracer network simulation software. The paragraph also includes a sample quiz with multiple-choice questions related to network devices and their functions.
✨ Quiz and Course Support
This paragraph continues the sample quiz from the previous paragraph, providing additional multiple-choice questions to test the understanding of network devices, their roles, and client-server relationships. It also encourages viewers to support the course by subscribing, liking, commenting, and sharing the video, as well as considering donations via cryptocurrency or Patreon.
🔚 Closing Remarks
This short paragraph serves as a closing remark, thanking the viewers for watching the video.
Mindmap
Keywords
💡CCNA 200-301
💡Packet Tracer
💡Network Devices
💡Client-Server Model
💡Local Area Network (LAN)
💡Router
💡Switch
💡Firewall
💡Network Security
💡Next-Generation Firewall
Highlights
This course aims to be a complete course for the CCNA, including everything you need to pass the exam, all 100% free.
This course is for anyone who wants to pass the CCNA 200-301 exam or learn about computer networking.
A network allows nodes to share resources, where a node can be a router, switch, firewall, server, or client.
A client is a device that accesses a service made available by a server, and a server is a device that provides functions or services for clients.
Switches are used to forward traffic within a LAN (Local Area Network), providing connectivity to hosts within the same LAN.
Routers are used to provide connectivity between LANs and send data over the Internet.
Firewalls are specialty network security devices that control network traffic entering and exiting your network, monitoring and controlling traffic based on configured rules.
Next-generation firewalls combine traditional firewall features with more advanced filtering functionalities.
Host-based firewalls are software applications that filter traffic entering and exiting a host machine, like a PC.
There will be end-of-video quizzes, pre-made flashcards using Anki software, and practice labs using Cisco's network simulation software Packet Tracer for each lecture.
The first video's quiz questions test understanding of network devices like switches, routers, firewalls, servers, and clients.
Switches are designed to connect many end hosts in the same LAN together, with many network interfaces.
Servers provide functions or services for clients, while clients access services made available by servers.
Routers are designed to connect and forward network traffic between multiple networks.
Next-generation firewalls combine traditional firewall features with advanced filtering functionalities.
Transcripts
Welcome to my complete CCNA, Cisco Certified Network Associate course. This is Jeremy’s
IT Lab. Since this is the first video, allow me to introduce the course. This course aims
to be a complete course for the CCNA, including everything you need to pass the exam, all
100% free. There will be lecture videos covering every
topic on Cisco’s official exam topics list, practice quizzes covering the material in
each lecture, flashcards to help you review and remember what you learned, practice labs
using Cisco’s network simulation software Packet Tracer, and at the end multiple practice
exams to get you ready for the real thing. Although this course will be based on Cisco’s
official exam topics list, I also want to give you extra information to improve your
understanding of networks in general. That additional context should also help you understand
the exam topics.
Because this is the first video in the series, I want to talk about who this course is for.
This course is for anyone who wants to pass the CCNA 200-301 exam. At the time of recording
this video, this is a new exam that isn’t released yet, but will be coming on February
24th, 2020. Although a lot of the information will overlap with the old CCNA, the course
will be based on the exam topics for the 200-301 exam
This course is for anyone who wants to learn about computer networking. You don’t necessarily
have to take the CCNA 200-301 exam, this course will cover lots of valuable information regarding
computer networking even if you’re not aiming for the CCNA.
The only requirement for this course is that you have a basic familiarity with computers.
I will cover all of the foundational networking knowledge at the beginning of the course,
so you don’t need any prior knowledge of networking, and you also don’t need to know
programming or anything like that to start this course.
With no further ado, let’s get started! Our first lesson will cover network devices.
This knowledge will be the foundation which we will build upon during the rest of this
course. Take a look at this sample network here. Do you know what each of these symbols
represents, and their function in a network? At the end of this lesson, you’ll know these
and more, and how they work together to make a network. We won’t go into too many details
in this lesson. There’s plenty of time to dig deeper in future lessons, but these first
few videos are meant to give you the foundational knowledge which we will build upon in future
lessons.
So, what is a network? Let’s ask our friends at Wikipedia. ‘a computer network is a digital
communications network which allows nodes to share resources’. Well, if you didn’t
understand before, you probably still don’t after reading just that. Let’s look further.
The definition states that a network allows nodes to share resources. What is a node?
I’ll introduce some types of network nodes here, some of which appeared in the sample
network on the previous slide.
This is a router. You’ve probably heard the word before and have a general idea of
what a router is. But I’ll explain a router’s function in this lesson.
Next, this is a switch. Maybe you’re familiar with what a switch is, maybe not. It serves
a different function than a router, but is also similar in many ways.
This next one is a firewall. You’re probably familiar with firewalls, and you most likely
have a firewall installed on your computer. That’s a software firewall, but large networks
usually have a hardware firewall, a separate network appliance, which helps protect the
network.
This next symbol represents a server. If you know computers, you surely have heard of servers
before. What exactly do they do? Well, if you’re watching this video, you’re getting
it from a server on the Internet.
The last symbol in this slide is a client. You’re using a client to watch this video,
whether it’s a smart phone, a laptop, a desktop PC, or whatever. What exactly is a
client? Let’s get into it. Over the next few slides let’s build a sample network
and look at the functions of each of these network nodes in the network.
You might also hear clients, as well as the previous node type, servers, referred to as
end hosts or endpoints
Okay, so we looked at some types of network nodes, but we didn’t really examine exactly
what each type of node does in a network. Let’s build a network and examine each node’s
role.
So, here we have two PCs. PC1 on the left, and PC2 on the right. As is, this isn’t
a network. However, if I connect them together with a cable…
We now have a network. That’s right, two PCs connected together actually makes a network!
Now, it’s a very simple network, but if we take a look at that Wikipedia definition
once more…
‘A computer network is a digital telecommunications network which allows nodes to share resources’
Now that these two nodes are connected, they can share resources...
And essentially have a conversation with each other.
Now, I’m representing clients with this symbol. But there are all kinds of devices
which can be network clients.
For example, a laptop or
Desktop PC running Microsoft Windows. Or how about an iMAC running macOS. Or even an apple
iphone running iOS. These are just a few examples of devices which can be network clients.
So, let’s give a simple definition of a client.
A client is a device that accesses a service made available by a server.
Okay, since server is part of the definition of a client, to understand one, you have to
understand the other.
So, what’s a server? Let’s take a look.
I used this symbol to represent a server. When you think of the word server, you may
thing of something like this IBM server, or this DELL server. And indeed, these are powerful
servers, and you’ll see rows and rows of servers like these in data centers. However,
not all servers look like this. In fact, any of the clients we looked at in the previous
slide can be servers too! How is that possible? Well, let’s look at the definition of a
client again, and then compare it to the definition of a server.
The definition we used for a client was ‘a client is a device that accesses a service
made available by a server.’ So, we can basically reverse that definition to know
what a server is.
‘A server is a device that provides functions or services for clients.’ So, let’s look
at the simple network of two PCs connected with a cable that we saw before.
Remember this network? Watch this little exchange between the two PCs and think which of them
is the server and which is the client.
PC1 asks PC2 for the file ‘image.jpg’
PC2 responds and sends the requested image file. So, which is the client and which is
the server? Well, PC1 is the one requesting the service, requesting for the image to be
sent. And PC2 is the one providing the service, the one sending the image. So that makes PC1
the client, and PC2 the server.
Let’s look at another example of a client-server relationship. On the left is your computer,
or perhaps your smartphone, whatever you’re using to watch this video. On the right is
a YouTube server which contains this video. What do you think the blue cloud in the middle
represents?
The answer is, The Internet. In network diagrams, a cloud is often used to represent the Internet,
or in any situation where the details of that part of the network aren’t necessary. The
Internet is a very complex network, and for the sake of this diagram all we need to know
is that data from your computer passes through the Internet to reach the YouTube server.
The exact details of the Internet aren’t important for this diagram, so we can simply
use this cloud to represent the Internet.
So, your computer sends a request to the YouTube server for this youtube page, including the
video.
And youtube’s server sends the data, passing through the Internet, back to your PC.
However, YouTube doesn’t send the data all at once.
It sends you a stream of data until you’ve watched the whole video.
For one more example, let’s say your want to get a video from your friend. You both
have iphones, so you ask him to send you the video by airdrop.
Your phone requests the video.
And his phone responds, sending the video. You probably know it by know, but which phone
is the client and which is the server?
As you probably guessed, your phone on the left is the client.
And your friend’s phone on the right is the server.
To review once more. A client is a device that accesses a service made available by
a server. And, a server is a device that provide functions
or services for clients. Also, keep in mind the same device can be a client in some
situations, and a server is other situations.
Okay, hopefully you have a better idea of what a client is and what a server is. Now
let’s build out the network further, and show the next part of the connection between
end hosts and the Internet. Let’s say this is a network for an Enterprise,
and this Enterprise has a branch in New York, and a branch in Tokyo. Of course, a real Enterprise
branch will have more than just a couple PCs or a couple servers, but I also couldn’t
fit an entire network on this one slide! Typically you don’t connect end hosts like
PCs or servers directly to each other. You aggregate the connections to a device called
a switch.
As you can see, the two PCs are connected to SW1, and the two servers are connected to
SW2. Switches have lots of interfaces for you to connect end hosts to.
Look at this Cisco Catalyst switch. As you can see, lots of interfaces, or ports, to
plug your PCs or servers into. Switches are used to forward traffic within
a LAN, a local area network.
PC1 and PC2, as well as other devices plugged into SW1,
such as a network printer, or another PC, all reside on the same local area
network. The same goes for any devices connected to SW2 in the Tokyo Branch.
So, we have one LAN on the left, and one LAN on the right. The hosts within each LAN can
send data to each other, for example PC1 to PC2.
However, these switches cannot connect directly to the Internet.
And send data between the two LANs.
So let’s talk more about switches. Here on the left is the same Cisco switch from
the last slide. It’s a Catalyst 9200 model switch. On the right is a Catalyst 3650 model
switch. Catalyst switches are Cisco’s enterprise-grade switches, used by many enterprises to connect
their LANs. Now let’s review some characteristics of
switches.
Switches have many network interfaces or ports for end hosts, such as PCs, to connect to,
usually 24 or more.
Switches provide connectivity to hosts within the same LAN, meaning Local Area Network.
We’ll cover the details of LANs later, but for now just know it means end hosts within
the same area, like a bunch of computers on one floor of an office, or perhaps an entire
small office, or your home network.
Finally, switches do not provide connectivity between LANs or over the Internet. To do so,
we need another kind of network device.
That device is a router.
We can connect the switches to routers like this, and then connect the routers to the
Internet.
When end hosts in the New York Branch LAN want to communicate with end hosts in the
Tokyo Branch LAN, they will send the data to their router, R1, which will then forward
it to the Tokyo Branch LAN via the Internet. For example, if PC1 in the New York Branch
wants a file on SRV1 in the Tokyo Branch, it will send the request to R1 via SW1, which
will forward it over the Internet to R2, which will then send it to SRV1 via SW2.
The reply will then follow the reverse path back to PC1.
So, let’s talk about some of the characteristics of routers.
These are a few examples of Cisco routers you might find in use in an enterprise network.
The ISR 1000 and ISR 4000 have their network interfaces on the back, but if you look at
the ISR 900 you can probably notice a difference between a router and a switch. Let’s bring
up one of the switches we looked at before.
Compared to this Catalyst 9200 series switch, the ISR 900 router has relatively few network
interfaces. That’s one characteristic of routers compared to switches.
Routers have fewer network interfaces than switches.
Also, remember that switches are used to forward data within a LAN. Routers do the opposite.
Routers are used to provide connectivity BETWEEN LANs. And, because of that,
Routers are therefore used to send data over the Internet.
Here’s our network once again, but this time there’s a difference..
There is an attacker somewhere in the Internet, with an arsenal of many ways he could attack
our networks to steal information or otherwise damage our Enterprise. Although routers can
also provide some basic security features, what we should really be using to protect
our networks is…
A firewall. Firewalls are specialty network security devices that control network traffic
entering and exiting your network. Firewalls can be placed ‘outside’ of your router,
like FW1, or ‘inside’ of your network, like FW2. What’s important is that they
protect the end hosts inside, like the PCs and Servers in this network. Firewalls must
be configured with security rules to determine which network traffic should be allowed and
which should be denied. If you configure the rules properly, if PC1 in the New York Branch
tries to access SRV1 in Tokyo, the firewalls should permit the traffic through.
The return traffic from SRV 1 to PC1 should be allowed as well.
However, if the attacker tries to access anything inside of our networks, the firewall should
block it.
So let’s look at a couple of Cisco’s firewalls. At the top here are two examples of Cisco
firewalls. On the left is an ASA5500-X series firewall. The ASA, or adaptive security appliance,
is Cisco’s classic firewall. Although the ASA is their classic firewall, modern
ASAs include modern features of so-called ‘next generation firewalls’, including
things like IPS or intrusion prevention system. You’ll hear a lot more about that in the
security section of this course. On the right is a Firepower 2100 series firewall. This
is a next-generation firewall as well. Okay, let’s review some characteristics
of firewalls.
Firewalls monitor and control network traffic based on configured rules. You explicitly
configure which network traffic should be allowed in to your network, and which should
not.
Firewalls can be placed ‘inside’ the network or ‘outside’ the network. Meaning, the
firewall can filter traffic before it reaches the router, or after it has passed through
the router. In some cases, you might have a firewall inside and outside the network!
Firewalls are known as ‘next-generation firewalls’ when they include more modern
and advanced filtering capabilties. Both of these Cisco firewalls are considered ‘next-generation
firewalls’. Now, I have one more thing to look at regarding firewalls.
What about the firewall on your computer? Let’s take a brief look.
The two firewalls we looked at in the previous slide are network firewalls. Network firewalls
are hardware devices that filter traffic between networks. These are the kind of firewall we
will focus on in this course, as it is a networking course. However, there are also Host-based
firewalls. Host-based firewalls are software applications that filter traffic entering
and exiting a host machine, like a PC. Your PC almost certainly has a software firewall
installed, as it should. Even in a network with a hardware firewall, each PC should include
a software firewall as an extra line of defense.
Okay, now we’re back to our definition of a network. Do you understand more about each
of these types of network nodes? Keep in mind, there are other kinds of network devices, and
we’ll cover some of those later in this course. Stay tuned for this lecture’s supplementary
materials which will help you review and test your knowledge. In the next lecture we will
look at the next two sentences of this Wikipedia definition of a computer network, focusing
on the various kinds of connections between these network devices.
For this lecture, and all other lectures, there will be supplementary materials to help
you practice and improve your understanding. There will be three primary resources:
End-of-video quizzes after each video. This video’s quiz will be coming up right after
this slide.
There will also be pre-made flashcards to review the
lecture’s material, using the
flashcard software ‘Anki’. These flashcards will be included in the description of each
video. Since this is the first video, however, I will make a separate video explaining how
to download and use the Anki software. If you already know how to use Anki, feel free
to download this video’s flashcards in the description and get started. Otherwise, wait
for the next video and I’ll show you how. Just one recommendation: As I will upload a
separate flashcard deck for each video, instead of having many separate decks, I recommend
you create one CCNA deck and then transfer the new cards to that central deck.
Finally, there will be a practice lab using Cisco’s network simulation software ‘Packet
Tracer’ for each and every video. I will release separate videos for these practice
labs, and will include the packet tracer file in the descriptions of those videos so you
can download them, and complete them yourself. The packet practice lab for this video will
be a demonstration of how to download packet tracer and get started with it.
Now, let’s go on to this video’s quiz. Select the best answer from the available
choices. In some cases there are multiple answers that could possibly be correct, but
there will always be one best choice. Cisco exams tend to have lots of questions like
that, so hopefully some of these will be able to test you in a similar manner. This first
video’s quiz questions, however, shouldn’t be too difficult.
Your company wants to purchase some network hardware to which they can connect the 30
PCs in your department. Which type of network device is appropriate? A, a router. B, a firewall.
C, a switch. Or D, a server. Pause the video to think about your answer. The answer is
C, a switch. Let’s analyze each of the incorrect answers first, then the correct answer.
A router, like this Cisco ISR 900 series router, is designed for forwarding traffic between
networks, not for connecting lots of end hosts like PCs to.
Also, a router will not typically have 30 network interfaces to connect hosts to.
So, A, a router, is incorrect.
A firewall, like this Cisco ASA 5500-X series firewall, is designed to filter traffic as
it enters and exits the local network. It is not designed to connect directly to end
hosts, and typically will not have enough network interfaces for 30 hosts.
So, B, a firewall, is incorrect.
A server is an end host itself, not a networking device to which you will connect other end
hosts. So, D, a server, is incorrect.
A switch, like this Cisco Catalyst 9200 series switch, is designed to connect many end hosts
in the same LAN together. They include many network interfaces to connect hosts to.
So, C, a switch, is the correct answer. Okay let’s go on to the next question.
You received a video file from your friend’s Apple iPhone using AirDrop. What was his iPhone
functioning as in that transaction? A, a server. B, a client. Or C, a local area network. Pause
the video to think about your answer.
The answer is A, a server. Lets’ check the answers.
In this case your iPhone, not your friend’s iPhone.
A client accesses a service, it does not provide a service.
So, B, a client, is incorrect.
An end host like an iPhone does not function as a local area network (LAN) by itself. It
can, however, be a part of a local area network. So, C, a local area network, is incorrect.
A server is a device that provides functions or services for clients.
In this case, your friend’s phone provided the file to your iPhone.
So, A, a server, is the correct answer. Let’s go to the next question.
What is your computer or smartphone functioning as while you watch this video? A, a server.
B, an end host. Or C, a client. Pause the video to think about your answer. The answer
is C, a client. Let’s check the answers.
Your device is receiving a service, not providing one, so it is not functioning as a server.
Therefore A, a server, is incorrect.
Although your device is an end host, that does not describe its function. Both servers
and clients are end hosts in a network. So, B, an end host, is incorrect.
Your device is receiving a service from YouTube’s servers. Therefore, it is functioning as a
client. So, C, a client, is the correct answer. Let’s
go to the next question.
Your company wants to purchase some network hardware to connect its separate networks
together. What kind of network device is appropriate? A, a firewall. B, a host. C, a LAN. Or D,
a router. Pause the video to think about your answer.
The answer is D, a router. Let's check.
Although a firewall can connect multiple networks together, its real purpose is to monitor and
control traffic as it enters and exits the network.
So, A, a firewall, is not the best answer.
The term ‘host’ can refer to any type of network node. So B, a host, is incorrect.
LAN stands for Local Area Network. A LAN is not a network device itself. So, C, a LAN,
is incorrect.
A router is a device that is designed to connect and forward network traffic between multiple
networks. So, D, a router, is the correct answer. Let’s go to the final quiz question
for this video.
Your company wants to upgrade its old network firewall that has been in use for several
years to one that provides more advanced functions. What kind of firewall should they purchase?
A, a host-based firewall. B, a next-level firewall. C, a next-generation firewall. Or
D, a top-layer firewall. Pause the video to think about your answer.
The answer is C, a next-generation firewall. Let’s check each answer.
A host-based firewall is a piece of software that runs on an end host, like the firewall
on your computer. It is not a network firewall. So A, a host-based firewall, is incorrect.
Next-level and Top-layer are not actual types of firewalls, so B and D are incorrect.
A next-generation firewall combines traditional firewall features with more advanced filtering
functionalities. So C, a next-generation firewall, is correct.
Thank you for watching! That’s all for this video. If you want to show your support, please
subscribe to the channel, like the video, leave a comment, and share the video with
anyone else studying for the CCNA. I also accept donations via cryptocurrency or Patreon
via the links in the description. That’s all for now.
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