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Файл:IT English through Short Films. Учебное пособие по английскому языку
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The best way to share your internet connection between multiple
devices is to add a router between your modem and your devices.
A router is a device that routes traffic between two different networks.
The two different networks we would be connecting this router would
be the public network of your ISP and your new private network on the
other side of the router. Now instead of everything being on the public
network or the Internet you can have all of your devices behind the
router on the private network, which is better for security. A router will
also take care of handing out IP addresses to all the devices you connect
to it. And it will have plenty to give out. So you connect your modem to
the LAN or Internet port on the router and then connect your devices to
any of the land ports on the router. These ports are in essence a switch
built into the router if you want to think of it in that way. If you need
more Ethernet ports than your router has you can add a switch. This
picture will show you how to connect a switch to a router.
All of our devices have to be connected to the network with an Ethernet
cable. To give wireless access to this network you could add a wireless
access point. You plug in your wireless access point into one of the
LAN ports on the router or to a switch somewhere in the network. Add
power if your switch or router won’t provide it. After a tiny bit of
configuring you have wireless access.
If a modem and a router and a switch and an access point sound
somewhat overwhelming then there’s good news for you. You’d rather
than have all of these separate devices you can get them all in one unit.
This is what I have. Most people call it a router and this is correct. But
this is a router switch access point combo. Technically it is a router that
has LAN ports built in which you could call the switch with built-in
access point. You can even rent devices from your ISP that are modem
router access point combo units, everything you need in one unit.
Leasing one of these combo units is usually the cheapest way to get
started but rent can end up over the months. Plus these combo units
from the ISPs are known for nor having great private network speed and
few options and are oftentimes limited by your ISP. If you want the
most out of your home network you can get a modem and then a
separate router access point combo unit which will give you full control,
better network speed and more features. You can find a cheap modem
and a cheap router on Craigslist (интернет объявления). Just make sure
the modem you get is compatible and make sure the router will at least
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support the 802 11n standard or better. It will say on the box or is
usually easy to find in the specs. Now we can easily understand what
each device is in my rack in my closet and what each one does. First,
this is my modem which is connected to the LAN Internet port on my
router. This is my router. It routes the traffic between my private
network and the public network letting me share my internet connection
between all my devices. The router has a built-in access point which
gives my wireless devices access to my network and in turn the Internet.
This is my patch panel (соединительная панель) which gives my
permanent Ethernet cables running through my walls a place to
terminate. We didn’t cover this in this video. This is just a large switch
that is connected to my router giving me many more Ethernet ports for
my devices. I like to wire anything I can and this last one is just a rack
mounted power strip.
12. THE INTERNET: IP ADDRESSES & DNS
https://www.youtube.com/watch?v=5o8CwafCxnU
(Paola): Hi! My name is Paola and I am a software engineer at
Microsoft. Let’s talk about how the internet works. My job relies on
networks being able to talk with one another, but back in the 1970s there
was no standard method for this. It took the work of Vint Cerf and Bob
Khan to invent the internet working protocol, to make communication
possible. This invention laid the groundwork for what we now call the
Internet.
(Vint Cerf): The Internet is a network of networks. It links billions of
devices together all around the globe. So maybe you’re connected with a
laptop or a phone through Wi-Fi. Then that Wi-Fi connection connects
to an internet service provider (or ISP) and that ISP connects you to
billions and billions of devices around the world through hundreds of
thousands of networks that are all interconnected.
One thing that most people do not appreciate is that the internet is really
a design philosophy and an architecture expressed in a set of protocols.
A protocol is a well-known set of rules and standards that if all parties
agree to use it, will allow them to communicate without trouble. How
the Internet actually physically works is less important than the fact that
this design philosophy has allowed the internet to adapt and absorb new
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communication technologies. This is because in order for a new
technology to use the Internet in some fashion, it just needs to know
which protocols to work with.
All the different devices on the internet have unique addresses. An
address on the Internet is just a number, similar to a phone number or a
sort of street address, that’s unique to each computer or device at the
edge of the network. This is similar to how most homes and businesses
have a mailing address. You don’t need to know a person to send them a
letter in the mail, but you do need to know their address and how to
write the address properly so the letter can be carried by a mail system
to its destination. The addressing system for computers on the Internet is
similar and it forms part of one of the most important protocols used in
internet communication simply called the internet protocol or IP. A
computer’s address then is called its IP address. Visiting a website is
really just your computer asking another computer for information.
Your computer sends a message to the other computer’s IP address and
it also sends along its origin address, so the other computer knows
where to send its response.
(Paola): You may have seen an IP address. It’s just a bunch of numbers.
These numbers are organized in a hierarchy. Just like a home address
has a country, a city, a street and a house number, an IP address has
many parts. Just like all digital data, each of these numbers is
represented in bits.
Traditional IP addresses are 32 bits long, with 8 bits for each part of the
address. The earlier numbers usually identify the country and regional
network of the device. Then come the subnetworks, and then finally the
address of the specific device. This version of IP addressing is called
IPv4. It was designed in 1973 and was widely adopted in the early 80s.
It provides for more than 4 billion unique addresses for devices
connecting to the Internet. But the Internet has turned out to be much
more popular than even Vint Cerf imagined and 4 billion unique
addresses won’t be enough.
We are now in the middle of multi-year transition to longer IP address
format called IPv6, which uses 128 bits per address and provides over
340 undecillion (ундециллион) unique addresses. That’s more than
enough for every grain of sand on Earth to have its own IP address.
(Vint Cerf): Most users never see or care about internet addresses. A
system called the domain name system or DNS associates names like
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www.example.com with the corresponding addresses. Your computer
uses the DNS to look up domain names and get the associated IP
address which is used to connect your computer to the destination on the
Internet. And it goes a little something like this:
(Laptop): Hey, hi there, I want to go to www.code.org.
(Server 1): Ehhh… yeah I don’t know the IP address for that domain,
let me ask around. Hey, anyone knows how to get to code.org?
(Server 2): Yeah, I got it right here. It’s 174.129.14.120.
(Server 1): Oh, okay, great, thanks. I’m gonna write that down and save
it for later in case I need it. Hey, here’s that address you wanted.
(Laptop): Awesome! Thank you.
(Paola): So how do we design a system for billions of devices to find
any one of billions of different websites? There is no way one DNS
server can handle all the requests from all devices. The answer is that
DNS servers are connected in a distributed hierarchy and are divided
into zones, splitting up responsibility for the major domains such as
.org, .com, .net, etc.
DNS was originally created to be an open and public communication
protocol for government and educational institutions. Because of its
openness, DNS is susceptible to cyber-attacks. An example attack is
DNS spoofing. That’s when a hacker taps into a DNS server and
changes it to match a domain name with the wrong IP address. This lets
the attacker send people to an impostor website. If this happens to you,
you are vulnerable for more problems because you are using that fake
website as if it’s real.
The Internet is huge and getting bigger every day. But the domain name
system and internet protocol are designed to scale, no matter how much
the Internet grows.
13. WHAT IS WORLD WIDE WEB?
https://www.youtube.com/watch?v=J8hzJxb0rpc
The World Wide Web, where you are likely watching this video, is used
by millions of people every day from everything from checking the
weather, ordering food and chatting with friends to raising funds,
sharing news, or starting revolutions. We use it from our computers, our
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phones, even our cars. It’s just there, all around us all the time. But what
is it exactly?
Well, first of all, the World Wide Web is not the Internet, even though
the terms are often used interchangeably. The Internet is simply the way
computers connect to each other in order to share information. When the
Internet first emerged, computers actually made direct calls to each
other. Today networks are all around us, so computers can communicate
seamlessly.
The communication enabled through the Internet has many uses, such as
email, file transfer, and conferencing. But the most common use is
accessing the World Wide Web. Think of the Web as a bunch of
skyscrapers, each representing a web server, a computer always
connected to the Internet, specifically designed to store information and
share it. When someone starts a website, they are renting a room in this
skyscraper, filling it with information and linking that information
together in an organized way for others to access. The people who own
these skyscrapers and rent space in them are called web hosts. But
anyone can set up a web server with the right equipment and a bit of
know-how.
There is another part of having a website, without which we would be
lost in the city with no way of finding what we need. This is the website
address, which consists of domain names. Just with a real life address, a
website address lets you get where you want to go.
The information stored in the websites is in the web languages, such as
HTML and JavaScript. When we find the website we are looking for,
our web browser is able to take all the code on the site and turn it into
words, graphics and videos. We don’t need to know any special
computer languages because the web browser creates a graphic interface
for us.
So in a lot of ways, the World Wide Web is a big virtual city where we
communicate with each other in web languages, with browsers acting as
our translators. And just like no one owns a city, no one owns the Web.
It belongs to all of us. Anyone can move in and set up a shop. We might
have to pay an Internet service provider to gain access, a hosting
company to rent web space, or a registrar to reserve our web address.
Like utility companies in a city, these companies provide crucial
services, but in the end not even they own the Web.
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But what really makes the Web so special lies in its very name. Prior to
the Web we used to consume most information in a linear fashion. In a
book or newspaper article, each sentence was read from beginning to
end, page by page, in a straight line until you reached the end. But that
isn’t how our brains actually work. Each of our thoughts is linked to
other thoughts, memories and emotions in a loose interconnected
network like a web.
Tim Berners-Lee, the father of the World Wide Web, understood that
we needed a way to organize information that mirrored this natural
arrangement. And the Web accomplishes this through hyperlinks. By
linking several pages within a website or even redirecting you to other
websites to expand on information or ideas immediately as you
encounter them, hyperlinks allow the Web to operate along the same
lines as our thought patterns.
The Web is so much a part of our lives because in content and structure,
it reflects both the wider society and our individual minds. And it
connects those minds across all boundaries, not only ethnicity, gender
and age but even time and space.
14. HOW THE INTERNET WORKS IN 4 MINUTES
https://www.youtube.com/watch?v=Sfzo4xm5eX8
In today’s video we will talk about the Internet and find out how it
works. If you thought that the Internet works by satellite, find out that
you were wrong. So how does the Internet work and where does it come
from? The Internet is everywhere, but still nowhere. It is on the phone,
TV or computer, but where exactly does it come from?
Every time you receive a notification, access a site or send an email, the
data is sent via cables that are found all over the globe and so reach the
recipient. The data you want to access on the Internet is very far away
from you and is stored at companies such as Google, Facebook or other
hosting companies. From here, your data may be transmitted to you via
a satellite, but this is useless because the bandwidth of a satellite is very
limited and leads to long delays.
So what’s the solution?
Well, find out that data on the Internet circulates mostly through fiber
optic cables that cross the Earth under seas and oceans, among sharks
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and other strange creatures. The cables are very thick to protect the
optical fiber inside which is very fragile and sensitive. These cables are
connected to landing stations located on the shores of the oceans and
from there the Internet goes to an entire continent forming a huge
network.
If we found out where the Internet comes from, now let’s see how it
works. To better understand, let’s take a concrete case. Let’s say you
want to access certain data from the Internet from a phone or laptop that
is connected to the Internet via cable or Wi-Fi via a router. The data you
want to access, for example a video on YouTube, is stored in a data
center on an SSD of a server.
But how does this data get to you?
Any device connected to the Internet is identified by a unique group of
numbers, called the IP Address and the IP address of your phone or
laptop, for example, is given by your Internet service provider. Also, the
server where the data you want to access is stored also has an IP
address. So through the IP, the information has a sender and a recipient.
Moreover, if you want to access google.com for example, it also has an
IP address, hidden under a domain name, to be easier to use, because for
us humans it is much easier for us to remember google.com than to
remember numbers like 105.39.4.284. This is where DNS technology
comes in, which works like a phone book. Specifically, DNS associates
a name for each website IP address in the world. From here, this data
request that you made, is transmitted to the respective server and the
data transfer to you starts. The data flows through the fiber optic cable
system in the form of light pulses and thus reaches your router. From
here, the data is transmitted by the router in the form of electrical signals
via internet cable or Wi-Fi.
But what if you use the Internet through mobile data?
Well, the signal is transmitted through the same optical cables to a cell
tower, and from here the Internet is transmitted to you in the form of
electromagnetic waves. In the end, I think it’s quite important to know
what the Internet is and where it comes from, given that we use it daily,
and without it our daily lives would have been much harder in all
respects.
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15. THE INTERNET: CYBERSECURITY & CRIME
https://www.youtube.com/watch?v=AuYNXgO_f3Y&t=214s
Hi, my name is Jenny Martin and I'm the director of cybersecurity
investigations at Symantec.
Today cybercrime causes huge problems for society personally,
financially, and even in matters of national security.
Just in the last few years, hundreds of millions of credit card numbers
have been stolen, tens of millions of Social Security numbers and
healthcare records were compromised, even nuclear centrifuges that
have been hacked, and unmanned aerial drones have been hijacked.
This is all done by exploiting vulnerabilities in hardware and software
or more often by taking advantage of unintentional decisions made by
the people using the software.
The people committing these cybercrimes don't fit a single profile or
motivation. It could be anyone from an international terrorist to a
teenager competing for bragging rights. Today the largest countries not
only have a regular army but also have a well-armed cyber army. In fact,
the next World War may not be fought with traditional weapons, but
with computers used to shut down national water supplies, energy grids,
and transportation systems.
Hi my name is Parisa and I'm Google's Security Princess. I've worked
on a lot of different Google products in a lot of different ways to try and
make our software as secure as possible. Now let's take a look at how
cybercrime works under the hood. We'll learn about software viruses,
denial-of-service attacks, and phishing scams.
In biology and life, a virus is an organism that is spread by coughing,
sneezing, or physical contact. Viruses work by infecting cells, injecting
their genetic material, and using those cells to replicate. They can make
people really sick and then spread to other people.
A computer virus works bit similarly. A virus is an executable program
that gets installed, usually unintentionally, and harms the user and their
computer. It's also possible for a virus to spread itself to other
computers.
Now how does a virus get on your computer in the first place? There are
a couple ways an attacker can infect someone's computer. They might
lure a victim into installing a program with deception about the
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program's purpose, so for example a lot of viruses are disguised as
security updates.
It's also possible that the software on your computer has vulnerability,
so an attacker can install itself without even needing explicit permission.
Once a virus is on your computer it can steal or delete any of your files,
control other programs, or even allow someone else to remotely control
your computer.
Using computer viruses, hackers can take over millions of computers
worldwide and then use them as a digital army, otherwise known as a
botnet, to attack and take down websites. This kind of attack is called a
distributed denial of service.
A denial of service is when hackers overwhelm a website with too many
requests. We call it a distributed denial-of-service when the attack
comes from many computers all at once.
Most websites are ready to respond to millions of requests a day, but if
you hit them with billions or trillions of requests, coming from different
places, the computers are overloaded and stop responding.
Another trick used by cybercriminals is to send large amounts of spam
email in an attempt to trick people into sharing sensitive personal
information. This is called a phishing scam. A phishing scam is when
you get what seems like a trustworthy email asking you to log into your
account, but clicking the email takes you to a fake website. If you log in
anyway, you've been tricked into giving your password away. Hackers
can then use your login credentials to access your real accounts to steal
information or maybe even to steal your money.
Fortunately there are many companies, laws, and government
organizations working to make the internet safer, but these efforts are
not enough. You may think when a computer system gets hacked the
problem was the security design or the software. Ninety percent of the
time the system gets hacked however, it's not because of the security
bug, but because of a simple mistake made by a human.
It turns out there are steps we can all take to protect ourselves. Often
your actions not only impact the security of your own data and
computer, but the security of everyone at your school, workplace and
home. With billions or trillions of dollars at stake, cybercriminals get
smarter each year and we all need to keep up.
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16. WHAT IS CRYPTO JACKING? WHY DO CRIMINALS
LOVE THIS CON?
https://www.youtube.com/watch?v=Gvkl4tJnbik
Crypto jacking is the unauthorized use of someone else’s computer to
mine cryptocurrency.
Hackers do this by either getting the victim to click on a malicious link
in an email that loads crypto mining code on the computer or by
infecting a website or online ad with JavaScript code that auto-executes
once loaded in the victim’s browser. In fact, hackers often will use both
methods to maximize their return. Unlike most other types of malware,
crypto jacking scripts do no damage to computers or victims’ data. They
do steal CPU processing resources—and sometimes the only sign a
victim will notice is slower performance as the crypto mining code
works in the background.
For individual users, slower computer performance might be just an
annoyance. Organizations with many crypto jacked systems can incur
real costs in terms of help desk and IT time spent tracking down
performance issues and replacing components or systems in the hope of
solving the problem.
At the EmTech Digital conference in 2018, Darktrace told the story of a
client, a European bank that was experiencing some unusual traffic
patterns on its servers. Night-time processes were running slowly, and
the bank’s diagnostic tools didn’t discover anything. Darktrace
discovered that new servers were coming online during that time—
servers that the bank said didn’t exist. A physical inspection of the data
center revealed that a rogue staffer had set up a crypto mining system
under the floorboards.
No one knows for certain how much cryptocurrency is mined through
crypto jacking, but there’s no question that the practice is rampant—for
the simple economic reasons: more money for less risk. And with
inexpensive kits available on the dark web, crypto jacking doesn't even
require significant technical skills. In fact, crypto mining delivery
methods are often derived from those used for other types of malware
such as ransomware or adware.
In 2017 Kaspersky Labs discovered a Google Chrome extension that
used Facebook Messenger to infect users’ computers, dubbed
FacexWorm, it was originally used to deliver adware. In 2018, Trend
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