The Internet: IP Addresses & DNS

Summary

In the video, Paola and Vint Cerf explain the fundamentals of the internet, highlighting the pivotal role of the internet protocol (IP) in enabling communication between billions of devices. They discuss the hierarchical structure of IP addresses, the transition from IPv4 to IPv6 to accommodate growth, and the domain name system (DNS) that translates human-readable domain names into IP addresses. The script also touches on the challenges of DNS spoofing and the importance of the internet's scalable design to adapt to its ever-expanding size.

Takeaways

• 🌐 The internet is a network of networks, connecting billions of devices worldwide.
• 🛠️ Vint Cerf and Bob Kahn invented the internetworking protocol, which enabled communication across different networks.
• 💡 The internet is based on a design philosophy and architecture expressed through protocols, which are sets of rules and standards for communication.
• 🏡 Just like a physical address, each device on the internet has a unique IP address that identifies its location within the network.
• 🔢 Traditional IP addresses are 32 bits long, but due to the rapid growth of the internet, a transition to the 128-bit IPv6 addressing system is underway.
• 🌟 IPv6 provides an enormous number of unique addresses, enough for every grain of sand on Earth to have its own.
• 🌐 DNS (Domain Name System) translates human-friendly domain names into IP addresses that computers use to connect to websites.
• 🔒 DNS is susceptible to cyberattacks, such as DNS spoofing, where hackers redirect users to fake websites by altering DNS records.
• 🌳 DNS servers are organized in a distributed hierarchy, with different servers responsible for different domains, allowing the system to scale with the growth of the internet.
• 🌟 The internet's design allows it to adapt and incorporate new communication technologies by simply adopting new protocols.

Q & A

Who are Vint Cerf and Bob Kahn, and what is their contribution to the internet?

Vint Cerf and Bob Kahn are credited with inventing the internetworking protocol that made communication between networks possible, laying the groundwork for what we now call the internet.

What is the definition of the internet according to the script?

The internet is defined as a network of networks, linking billions of devices together around the globe through a series of interconnected networks.

What is the significance of protocols in the internet's design philosophy?

Protocols are sets of rules and standards that allow different devices and networks to communicate without trouble, and they are crucial for the internet's ability to adapt and incorporate new communication technologies.

How does the internet use unique addresses for devices?

The internet uses unique addresses, similar to phone numbers or street addresses, to identify each device. This addressing system is part of the internet protocol (IP).

What is an IP address and how does it function in internet communication?

An IP address is a unique number assigned to a device on the internet, functioning like a mailing address that allows for the sending and receiving of information.

What is the structure of an IP address and how does it relate to a physical address?

An IP address is structured in a hierarchy, similar to a physical address with country, city, street, and house number. It is organized into parts, with traditional IPv4 addresses being 32 bits long, divided into 8-bit sections.

Why was the transition from IPv4 to IPv6 necessary?

The transition to IPv6 was necessary because the 4 billion unique addresses provided by IPv4 were insufficient for the growing number of devices connecting to the internet.

What is the domain name system (DNS) and how does it relate to IP addresses?

The domain name system (DNS) is a system that associates easy-to-remember names like www.example.com with their corresponding IP addresses, allowing users to access websites without needing to know the IP addresses.

How is the DNS structured to handle the vast number of internet requests?

DNS servers are connected in a distributed hierarchy and divided into zones, each responsible for major domains like .org, .com, .net, etc., to handle the vast number of requests.

What is DNS spoofing and how does it pose a threat to internet users?

DNS spoofing is a cyberattack where a hacker alters a DNS server to associate a domain name with the wrong IP address, redirecting users to a fake website, potentially exposing them to further security risks.

How are the internet protocol and domain name system designed to accommodate the growth of the internet?

Both the internet protocol and domain name system are designed to scale, allowing for growth and expansion of the internet without limitations due to the number of devices or websites.

Outlines

00:00

🌐 Understanding the Internet's Foundation

Paola, a software engineer at Microsoft, introduces the concept of the internet as a network of networks, highlighting the pivotal role of Vint Cerf and Bob Kahn in creating the internetworking protocol that enabled communication across different networks. Vint explains that the internet is a global system linking billions of devices through ISPs and various networks. He emphasizes the importance of protocols as a set of rules and standards that facilitate communication. The discussion also touches on the adaptability of the internet's design philosophy, which allows it to incorporate new technologies seamlessly. The concept of IP addresses as unique identifiers for devices on the internet is introduced, comparing them to physical addresses or phone numbers, and explaining how they are used in communication.

05:01

🌐 The Evolution of IP Addressing and DNS

Paola and Vint delve into the structure of IP addresses, comparing them to hierarchical home addresses with country, city, street, and house number components. They discuss the transition from IPv4, which provides over 4 billion addresses, to IPv6, offering an enormous number of addresses—sufficient for every grain of sand on Earth. The conversation shifts to the domain name system (DNS), which maps human-friendly domain names to their corresponding IP addresses, simplifying internet navigation. The script illustrates a DNS lookup process through a dialogue. The segment concludes with a discussion on the distributed nature of DNS servers, their susceptibility to cyberattacks like DNS spoofing, and the system's ability to scale with the growing internet.

Keywords

💡Internet

The internet is a global network that connects billions of devices, allowing them to communicate with each other. It is the main theme of the video, as it discusses the history, structure, and functionality of this vast network. The video explains that the internet is a network of networks, linking devices through various means such as WiFi and ISPs (Internet Service Providers), and enabling communication across the globe.

💡Internetworking Protocol

An internetworking protocol is a set of rules that allows different networks to communicate with each other. The video highlights the work of Vint Cerf and Bob Kahn in inventing the internetworking protocol, which was crucial for the creation of the internet. This protocol forms the backbone of how the internet functions, enabling diverse networks to interconnect and exchange data.

💡Protocol

A protocol in the context of the video refers to a standardized set of rules and conventions that facilitate communication between devices on the internet. Protocols are essential for ensuring that data is transmitted and received correctly. The video emphasizes that the internet is built on a design philosophy expressed through protocols, which allow for the integration of new technologies.

💡IP Address

An IP address is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. The video explains that IP addresses are similar to phone numbers or street addresses, identifying the location of devices on the internet. The video also discusses the transition from IPv4 to IPv6 due to the need for more addresses as the number of devices on the internet grows.

💡IPv4

IPv4, or Internet Protocol version 4, is the fourth version of the Internet Protocol used for identifying devices on the internet. The video mentions that IPv4 addresses are 32 bits long, providing over 4 billion unique addresses. However, with the rapid growth of the internet, IPv4 is being phased out in favor of IPv6 to accommodate more devices.

💡IPv6

IPv6, or Internet Protocol version 6, is the latest version of the Internet Protocol. The video explains that IPv6 addresses are 128 bits long, providing an enormous number of unique addresses, enough for every grain of sand on Earth to have its own address. This upgrade is necessary to support the ever-increasing number of devices connected to the internet.

💡Domain Name System (DNS)

The Domain Name System (DNS) is a system that translates human-friendly domain names (like www.example.com) into IP addresses that computers use to identify each other on the internet. The video describes how DNS is a critical component of the internet's infrastructure, allowing users to access websites without needing to know their numerical IP addresses. It also touches on the distributed nature of DNS servers and the potential for cyberattacks like DNS spoofing.

💡ISP (Internet Service Provider)

An Internet Service Provider (ISP) is a company that provides individuals and organizations with access to the internet. In the video, ISPs are mentioned as intermediaries that connect users' devices, such as laptops or phones, to the broader internet through WiFi or other means, facilitating access to billions of devices worldwide.

💡Cyberattacks

Cyberattacks refer to any malicious attempt to disrupt, damage, or gain unauthorized access to a computer system or network. The video specifically mentions DNS spoofing as an example of a cyberattack, where hackers manipulate DNS servers to redirect users to fake websites, potentially leading to further security risks.

💡Scalability

Scalability in the context of the video refers to the ability of the internet's infrastructure, such as the DNS and IP protocols, to handle growth in the number of users and devices. The video assures that despite the ever-increasing size of the internet, its foundational systems are designed to scale and adapt to accommodate this growth.

Highlights

Vint Cerf and Bob Kahn invented the internetworking protocol, laying the groundwork for the internet.

The internet is a network of networks connecting billions of devices around the world.

A protocol is a well-known set of rules and standards that allows communication between devices.

The internet’s design philosophy allows it to adapt and absorb new communication technologies.

Every device on the internet has a unique address, called an IP address, similar to a phone number or street address.

The addressing system for computers on the internet is part of the Internet Protocol (IP).

Traditional IP addresses (IPv4) are 32 bits long and provide more than 4 billion unique addresses.

The transition to IPv6 is happening now, with 128-bit addresses offering over 340 undecillion unique addresses.

DNS (Domain Name System) translates domain names into IP addresses to connect devices to websites.

DNS servers are distributed in a hierarchy to handle the massive number of website requests globally.

The openness of DNS makes it susceptible to cyberattacks, like DNS spoofing, where attackers reroute users to imposter websites.

DNS spoofing is a dangerous attack where users are sent to a fake website instead of the real one.

The internet protocol and domain name system are designed to scale regardless of the internet’s growth.

An IP address is similar to a mailing address, allowing computers to send and receive information accurately.

IPv6 ensures the internet can support a virtually infinite number of devices, more than enough for every grain of sand on Earth to have its own address.

Transcripts

Paola: Hi! My name is Paola, and I am a software  engineer here 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 Kahn to  

invent the internetworking protocol to make  communication possible. This invention laid the  

groundwork for what we now call the internet. Vint: 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 wifi, but  then that wifi 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 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. Vint: 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 the 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 widely adopted in the early 80s  

and 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’re now in the middle of a  

multi-year transition to a longer IP address  format called IPv6 which uses 128 bits per  

address and provides over 340 undecillion unique  addresses. That’s more than enough for every grain  

of sand on Earth to have its own IP address. Vint: Most users never see or care about  

internet addresses. A system called  the “domain name system” (or DNS)  

associates names like 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. (Then it goes a little somethin’ like this!)  

Voice 1: Hey, hi there, I  want to go to www.code.org.  

Voice 2: Mm… yeah I don’t know the, uh— the  IP address for that domain; let me ask around.  

Hey, do you know how to get to, uh, code.org? Voice 3: Yeah, I got it right here;  

it’s a 174.129.14.120. Voice 2: Oh, okay, great.  

Thanks. Yeah I’m gonna— I’m gonna write that down  and save it for later in case I need it. Hey,  

here’s that address you wanted. Voice 1: 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 cyberattacks. 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 attackers send  people to an imposter website. If this happens to  

you, you are vulnerable for more problems because  you are using that fake website as if it is 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.