In this section of the course,
we're going to explore network fundamentals.
Now, when I mention computer networks,
you probably have a myriad of different concepts
that are coming to your mind.
Maybe you're thinking about your everyday router and switch,
or maybe you're thinking about your home's wifi network
that connects you to the server
that's hosting the videos you're watching right now.
Networks, however, are not just confined to computers
or limited just to the internet.
They encompass a diverse range of connections
that extend to both the wireless networks
like wifi and cellular, as well as to wired networks
with things like ethernet and fiber optic connections.
Now, networks serve the essential purpose
of connecting a multitude of devices
that facilitate a seamless flow of data.
Take for instance, your smartwatch.
It communicates to with your smartphone using Bluetooth,
forming what's known as a personal area network, or a PAN,
because of the proximity
between your wrist and your cell phone.
Now, similarly, the wifi network in your home
also connects your tablet to the internet
using a wireless access point,
which is another form of a network,
which we call a local area network or LAN.
Further, we might have a desktop computer
that connects to a switch,
and that switch connects to a router,
and that router connects to a modem,
and that modem connects you to the internet.
And all these components are integral parts of your network,
and they all demonstrate the diversity
and complexity of even the most basic network architectures
in our environments today.
Now, over time, our various types of networks
have become converged.
Previously, we had distinct networks
that served different purposes for different things.
For example, you had one network
for your analog telephone phones,
and you had another one for digital data being sent
by your computers, and yet another one for video being sent
to the televisions in our homes.
But these days, we now have a unified network
that contains voice, data, and video
all traveling over a single network connection.
Modern smartphones are a great example of this
because you can see that they see everything
as digital data, whether it's a voice call, a text message,
your internet browsing, or a video you're streaming
on that device.
Now, given our heavy reliance on networks,
we need to ensure high availability and uptime
are being considered, and make sure
that they're of importance to us
when we're designing our networks.
Now, when I was working as an IT director,
my customers expected that we remained 100% uptime.
Now, this is an unrealistic expectation
because it implies that my team and I could run our networks
for years without even one second of downtime,
and that's really just not possible.
So instead, we published our service level agreement goal
as 99.999% uptime for our networks.
Now, this is commonly referred to as
the five-nines of availability.
This standard is not considered to be absolute,
but it does ensure a remarkable level of reliability
because it only allows around five minutes
of downtime each year.
Now, our challenge as network technicians and administrators
is to maintain this level of continuous operations
day after day and year after year.
Now, as we progress through this course,
you're going to gain the knowledge needed
to understand network fundamentals
and gain the skills needed to troubleshoot issues
that may arise, because this is essential
for maintaining your high levels
of network availability and uptime.
Now, these days, our corporate networks rely
on converged network designs
that can handle diverse activities like file sharing
and video chatting on platforms like Zoom and FaceTime,
and using things like browsing Google
or going to diontraining.com,
or even utilizing social media platforms like LinkedIn,
Facebook, TikTok, and other things.
Or you might be streaming videos like YouTube
and Disney+ and Netflix.
All of this can be done
using the exact same internet connection
because everything is treated as packets
inside of a larger IP network.
Now, this multitude of network traffic, though,
is constantly evolving with new additions as well,
and this becomes a significant challenge to us
as network technicians and administrators.
We are constantly being expected
to support an ever-growing range of network traffic
while maintaining that coveted five-nines of availability.
So in this section of the course, we're going to start out
by learning about some network fundamentals.
Our focus is going to be on Domain 1, networking concepts,
and Domain 2, network implementation,
and specifically we'll be looking at Objectives 1.2,
1.6, and 2.3.
Objective 1.2 states that you must be able to compare
and contrast networking appliances,
applications, and functions.
Objective 1.6 states that you must be able to compare
and contrast network topologies architectures and types.
And Objective 2.3 states that given a scenario,
you must be able to select
and configure wireless devices and technologies.
Now, first we're going to look at the different types
of network components that are used to create our networks,
including things like clients and servers and hubs
and switches and wireless access points and routers
and firewalls and load balancers and proxies
and intrusion detection systems
and intrusion prevention systems,
and all these other kind of things like that.
Now, we'll also be covering network resources,
including a discussion of client server models
and the peer-to-peer model.
Next, we'll discuss network geography,
including the discussion about personal area networks,
local area networks, campus area networks,
metropolitan area networks,
and wide area networks, including their size, scope,
and appropriate use cases.
We'll also look at a quick real-world demonstration
of how these three types of networks are going to be used
in modern vehicles to maintain our connectivity
as we're driving down the road.
After that, we're going to explore wired network topologies
including point-to-point, ring, bus, star, hub and spoke,
and mesh topologies.
Then we'll discuss the different wireless topologies
that you're going to be exposed to, including ad hoc,
point-to-point, infrastructure mode,
and wireless mesh networks.
Next, we'll cover data center topologies,
including things like the three-tiered model,
the collapse core model, the spine and leaf model,
and the ways traffic is classified as it enters,
leaves or transmits throughout our data centers.
Finally, we'll take a short quiz to see
what you learned in this section of the course
and review your answers to make sure you know
why the right answers were right
and the wrong answers were wrong.
So if you're ready, let's get started with our coverage
of network fundamentals in this section of the course.