Hey there! Let’s dive into how the internet works. Imagine the internet as a giant web connecting billions of devices worldwide. Whether you’re using a laptop or a smartphone, your device connects to the internet through a series of networks. These networks are linked together by internet service providers (ISPs), allowing your device to communicate with others across the globe.
Back in the 1970s, there wasn’t a standard way for networks to communicate. That’s when Vint Cerf and Bob Kahn came up with the internetworking protocol, which laid the foundation for the internet we use today. This protocol is a set of rules that devices follow to communicate smoothly. Thanks to this design, the internet can adapt to new technologies easily.
Every device on the internet has a unique address, known as an IP address. Think of it like a home address for your computer. Just as you need someone’s address to send them a letter, your computer needs an IP address to send and receive information from other devices.
Traditional IP addresses, called IPv4, are 32 bits long and can create over 4 billion unique addresses. However, with the internet’s rapid growth, we’ve started transitioning to IPv6, which uses 128 bits. This new system can provide more than 340 undecillion unique addresses, ensuring we won’t run out anytime soon!
Most people don’t need to remember IP addresses, thanks to the Domain Name System (DNS). DNS translates easy-to-remember domain names, like www.example.com, into IP addresses. When you type a website’s name, your computer uses DNS to find the correct IP address and connect you to the site.
DNS servers are organized in a hierarchy and divided into zones to manage the vast number of domain names. This system was originally created for government and educational use, but it’s now essential for everyone. However, because DNS is open, it’s vulnerable to cyberattacks like DNS spoofing, where hackers redirect you to fake websites.
The internet is constantly expanding, but thanks to the design of IP addresses and DNS, it can handle this growth. These systems ensure that no matter how big the internet gets, it remains a reliable and efficient way for devices to communicate worldwide.
Imagine your home is a computer on the internet. Design a unique IP address for it using the IPv4 format. Remember, an IPv4 address consists of four numbers separated by dots, each ranging from 0 to 255. Share your IP address with a classmate and explain why you chose those numbers.
Embark on a digital treasure hunt! Use a DNS lookup tool to find the IP addresses of popular websites. Write down the domain names and their corresponding IP addresses. Discuss with your classmates how DNS makes it easier to navigate the internet.
Research the structure of an IPv6 address. Create a poster that explains how IPv6 addresses are different from IPv4 addresses. Include examples of both types and highlight the benefits of using IPv6. Present your poster to the class.
In groups, role-play the process of DNS resolution. Assign roles such as the user, DNS resolver, root server, and authoritative server. Act out how a domain name is translated into an IP address. Reflect on how each part of the system contributes to finding the correct website.
Create a timeline that traces the history of the internet from its inception in the 1970s to the present day. Highlight key events such as the development of the internetworking protocol, the introduction of IPv4 and IPv6, and the evolution of DNS. Share your timeline with the class and discuss how these developments have shaped the internet.
**Sanitized Transcript:**
**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 communicate 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 Wi-Fi, but then that Wi-Fi connection connects to an internet service provider (ISP), and that ISP connects you to billions of devices around the world through hundreds of thousands of interconnected networks. 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 works physically is less important than the fact that this design philosophy has allowed it to adapt and absorb new communication technologies. This is because, in order for a new technology to use the internet, 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 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 it properly so the letter can be delivered 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 (IP). A computer’s address 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 series 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 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, providing for more than 4 billion unique addresses for devices connecting to the internet. However, 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” (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.
**Voice 1:** Hey, hi there, I want to go to www.code.org.
**Voice 2:** I don’t know the IP address for that domain; let me ask around. Hey, do you know how to get to code.org?
**Voice 3:** Yeah, I got it right here; it’s 174.129.14.120.
**Voice 2:** Oh, okay, great. Thanks. I’m going to write that down and save it for later in case I need it. 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, where a hacker taps into a DNS server and changes it to match a domain name with the wrong IP address. This lets attackers send people to an imposter website. If this happens to you, you are vulnerable to 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.
Internet – A global network of computers that allows people to access and share information worldwide. – Example sentence: Students use the internet to research information for their coding projects.
IP – Short for Internet Protocol, it is a set of rules governing the format of data sent over the internet or local network. – Example sentence: Every device connected to the internet has a unique IP address to identify it.
Addresses – Numerical labels assigned to each device connected to a computer network that uses the Internet Protocol for communication. – Example sentence: The computer’s IP addresses help it communicate with other devices on the network.
DNS – Short for Domain Name System, it translates domain names into IP addresses so browsers can load internet resources. – Example sentence: When you type a website name into your browser, the DNS helps find the correct IP address.
Devices – Electronic machines or tools that can connect to the internet, such as computers, smartphones, and tablets. – Example sentence: Many students use multiple devices to access their online coding classes.
Networks – Groups of interconnected computers and devices that can communicate with each other. – Example sentence: School networks allow students to share files and access the internet for research.
Protocol – A set of rules or standards that define how data is transmitted and received over a network. – Example sentence: The HTTP protocol is used to transfer web pages over the internet.
Unique – Being the only one of its kind; unlike anything else, often used to describe identifiers like IP addresses. – Example sentence: Each website has a unique domain name that distinguishes it from others.
Domain – The part of a network address that identifies it as belonging to a particular domain, such as .com or .org. – Example sentence: The domain name for our school’s website ends with .edu.
Communicate – To exchange information between devices or systems over a network. – Example sentence: Computers communicate with each other using specific protocols to share data efficiently.
