Networking Module 4 Introduction
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8 hours 53 minutes
welcome to domain for where we're going to be looking at networking
in this domain
comes here, asks us to look at the following.
I have to set up and configure a basic SOCO wrapped up.
Remember, SoHo stands for small office Home office.
We're also going to look later on at comparing and contrasting cellular, wireless and wired connections
and comparing and contrasting different methods of sharing and storage.
But here we're in module 4.1,
given a scenario, setup and configure a basic SoHo writer,
wired or wireless.
So here we're going to look at how to verify Wired and Internet connections
for WiFi wireless connections.
There's three types of security that could be enabled weapon W P A and W P A. To.
So be looking at the three of those and comparing them.
And when setting up a wireless network,
you have to configure certain things so specifically, we're going to look at configuring the S S i D, which is really just the name of the WiFi network,
the administrator password passwords to connect to the WiFi and firmware updates.
But first, let's do a little introduction to networking.
So what is a network
well. We can define it as two or more computing devices connected to each other and able to communicate with each other
that actual connection between two devices can be wired.
Or it could be wireless.
Wyatt connections can include copper cabling, where electrical signals passed from one device to another.
But wired networking in some cases can also include fiber optic cables, where light waves are used to transmit information.
Wireless networks use radio waves for communication, such as your home WiFi
or your cell. The cell phone connection
networks can either be self enclosed or connected to other networks. So, for example, I can build a network at home and not connected to the Internet, in which case it is a self enclosed network. There's no way of getting out to other networks or to the Internet,
and there's also no way for someone outside to come in and attack that network.
Um, but most of us don't live in that kind of splendid isolation.
So we do connect to the Internet and into that itself is basically just a collection of thousands of networks connected to each other through devices call routers.
You may have heard the term protocols in relation to networking.
Well, let's talk about these a little bit.
The word protocol in the real world refers to a set of rules about how to do certain things.
For example, diplomatic protocols indicate how to behave in front of dignitaries and world leaders, and so on.
Military protocols indicate how the members of the military should behave.
For example, do you need to salute someone who is superior or inferior to you?
Also think about language
when I communicate. Hopefully you're understanding me, and I'm speaking in English
now. English is just a set of rules about how words are formed, how they pronounced, how they put together into grammatical sentences, and so on.
Another languages German German has very different rules about how words are written, pronounced spelt
and so on.
Now, if you have two people, one who only speaks English and the other who only speaks German,
clearly they're gonna find it hard to communicate with each other.
We'll come back to that idea when we look ATT network protocols.
So you know, we could say languages set of protocols.
So what are network protocols? While similar to human language, they are a set of rules about how information is formatted, how it's transmitted and how it's received by computing devices.
protocol that is pretty much used everywhere in the world today is called T C P I. P. So the Internet and most networks use that protocol,
and this has become a kind of standard protocol. In the early days of networking, there were several competing protocols on. For example,
Microsoft used a protocol called Net Buoy
on Dhe. Novell, which is a company that used to dominate networking at one time,
used the protocol Cole I. P. X SPX Now these were proprietary protocols developed by the particular vendors and controlled by them.
Meanwhile, in the Internet, in the TCP in the UNIX world,
TCP i p was the protocol that was used
eventually, what happened to cut a long story short is all the other vendors
gave up on their own protocols and switched over to T C P i. P.
So T. C P I. P has become the default protocol. And that's good in many ways having a single default protocol because, remember, protocols are like human language.
In the old days, if you had one computer running neck buoy and another computer running I p X.
They were speaking two different languages and were not able to communicate directly with each other.
These days we don't have that problem because virtually every computing device you come across runs the protocol T c p i p. So computing devices can communicate with each other Using a common language,
TCP I P was developed as a research project by DARPA.
This was to set up reliable communication
across large geographical distances.
That was the original idea behind the experiment. They probably never imagined that one day it would form the basis off what we called the Internet. Or that you would even have something like the Internet, where something like seven billion devices are currently concurrently connected to this ever expanding network.
One term you will hear when thinking or talking about networking is the term packet,
and it's useful to understand what is meant by a packet.
When we're transmitting information across the network, we don't just send it as one long continuous stream.
One reason for that is is usually a ll. The computing devices that are connected to a network are sharing the medium
So, for example, in a wired network, singles are traveling over the same set of wires,
and so it would not be very efficient if one device was able to monopolize access to that shared communication medium,
let's say I would need it to send a 10 megabyte file across the network.
If my computer was allowed to take over the network and then transmit the entire 10 megabytes,
that would mean in that time while it's transmitting it, no other devices access to the network.
So instead, what happens is
large amounts of data are chopped up into smaller
chunks of data, and these we call packets.
Each packet is then transmitted independently across the network,
and packets travel across the network, eventually arriving at the appropriate destination. And it is actually possible that packets arrive out of sequence at the other end.
However, at the destination, the packets are reassembled into the correct order, and the original data is
as an analogy. Think about this. If I wanted to send a large document through the mail,
I could print out the entire document several 1000 pages and stick that all in a large envelope and mail that across, you know the mail system,
or I could break it up into smaller chunks on. I could maybe have several envelopes each containing 10 pages of the document and send all of those through the mail system.
And, you know, they may arrive at the other end out of sequence.
But once they arrive, they're all reassembled back into the original document.
That's kind of what we're doing when we send data across a network.
So that said earlier, T c P I. P is actually a collection of protocols
on. We typically refer to that as a protocol sweet.
Each protocol is responsible for different parts off delivering information across the network.
One of the central protocols, his I p
My Pee, is used to rout packets through complex networks like the Internet and deliver them to the correct computer.
When I tell you that today it is estimated that at any one time up to seven billion devices are connected to the Internet simultaneously,
so delivering your message to the right one of those is no easy task.
But I p accomplishes that,
and I pee runs both on every computing device and devices called routers, routers are the devices on the network that figure out how to deliver the packet.
Another major protocol is TCP.
This is used for two things, firstly, to deliver to the right application.
And that's because these days most operating systems are multi tasking, meaning they're running several applications at the same time.
So when a packet arrives across the network, we need to know which application it's meant for.
And this is achieved with by TCP By putting in port numbers into the package, those port numbers indicate which particular
application you're trying to talk to.
The other thing that TCP does is it provides reliable delivery, and it does this by putting a sequence number in each packet
and then waiting for acknowledgements from the other end to make sure that every packet sent has actually been received.
If a packet is not received, TCP agree, transmits it.
Http is another very common protocol. This is used to connect to Web servers and download Web pages. So when you open up your browser and you connect to a website,
it's using http to make that connection
popped. Three. I'm up for an SMTP are all protocols used to deliver email across the Internet
and S s l and T l s. These air protocols that would develop later on
to provide security for connections.
In the early days off T c p i. P remember that the project they were working on was how to ensure reliable delivery across large geographical areas. And they weren't particularly concerned about security because they never thought that this would one day be used as a protocol to link together
billions of devices across the Internet.
So security is often added as an afterthought in TCP I peep.
And so one example of that afterthought is the development of these protocols as the cell and T L s.
Well, they do is they add security to the connection firstly, by encrypting the connection.
So, you know, when you go on to study networking in more detail, you know there are devices and software known as packet sniffers. These can capture these packets that they travel across the network
if they're not encrypted. Anybody capturing those packets could read the contents.
So a solid t l s
encrypt the data. That is, they scrambled the data before sending it across the network.
The other thing that assailant ear less provide for his device authentication.
For example, If I connect to Microsoft website across the Internet,
how do I know for sure it's actually Microsoft's Web site, and not maybe a spoof website set up by a malicious user?
Well, if I'm using as a silent E l s, they will check and authenticate the Web server before allowing me to connect to it.
So setting up networks in a small officers and home offices
typically the only real
networking device there is what we typically called the home router,
and this forms the core of the network.
Now the home raka has within it
the following capabilities.
it allows you to plug wire devices in
so these yellow ports that you see here
those are called R J 45 you can plug in wired devices into those ports.
It also, of course, has
wireless connectivity, so we can see there's an antenna here,
and that's us up a wireless network, which we typically call WiFi.
This allows wireless devices to connect to the network as well, such as your smartphone or your tablet or your laptop
so schematically the connection looks like this.
We have the Internet,
and then we have a wired connection provided by our Internet service provider, which these days tends to be your cable company, the same company through which you get cable TV.
So the cable that comes in plugs into the cable modem
and from the cable modem, you have a cable with R J 45
Jack's on each end, and that plugs into your home router.
And then, as we've seen, your home writer, then allows wired devices and wireless devices to connect and
gain access to the Internet.