The Internet: IP Addresses & DNS

00:06:44
https://www.youtube.com/watch?v=5o8CwafCxnU

摘要

TLDRThe internet is a complex yet fascinating creation that relies on a network of interconnected devices and computers to function. It was the visionary work of Vint Cerf and Bob Kahn in the 1970s that paved the way with the development of an internetworking protocol, enabling communication across diverse networks. Today’s internet connects billions of devices, from smartphones to complex servers, all over the globe. Central to its function is the use of protocols, which are essentially agreed-upon rules for communications. The core protocol that allows the internet to function is the Internet Protocol (IP), which includes assigning unique addresses (IP addresses) to devices for identification and communication. Initially designed as IPv4, this protocol is gradually being replaced by IPv6 to accommodate the exponential growth of devices online. Additionally, the Domain Name System (DNS) plays a crucial role, translating human-readable domain names into IP addresses. Despite potential cyber threats such as DNS spoofing, the internet's capacity to scale and adapt ensures it continues to meet the ever-expanding demands of our digital world.

心得

  • 🌐 The internet connects billions of devices globally through interconnected networks.
  • 🧩 Vint Cerf and Bob Kahn developed the foundational protocol for internet communication.
  • 📜 Protocols enable standardized communication across the internet.
  • 📞 Every device has a unique IP address, similar to a postal address.
  • 🔗 DNS translates domain names into IP addresses for browser connection.
  • 🆕 IPv6 offers extensive IP addresses to cater to the growing internet demand.
  • 📈 The internet adapts to new technologies through flexible protocols.
  • 🔐 DNS is susceptible to attacks like DNS spoofing, redirecting users to fake sites.
  • 📚 Understanding IP structure is essential for efficient network management.
  • 🌀 The design architecture of the internet supports endless scalability.

时间轴

  • 00:00:00 - 00:06:44

    Paola introduces herself as a software engineer at Microsoft, talking about the importance of networks being able to communicate with each other, which was not possible until Vint Cerf and Bob Kahn developed the internetworking protocol in the 1970s. This protocol laid the foundation for today's internet, which is essentially a network of networks, allowing billions of devices to connect worldwide. The internet is based on a design philosophy expressed in protocols, which allow different networks to communicate. Vint Cerf explains that each device on the internet has a unique address, called an IP address, similar to a phone number or street address, which is part of the internet protocol.

思维导图

Mind Map

常见问题

  • Who invented the internetworking protocol?

    Vint Cerf and Bob Kahn invented the internetworking protocol.

  • What is an IP address similar to?

    An IP address is similar to a phone number or a street address, unique to each device on the internet.

  • What is the current version of IP addressing?

    The current version being transitioned to is IPv6, which uses 128-bit addresses.

  • How does DNS help users?

    DNS associates domain names with IP addresses, allowing users to connect to websites without needing to know the IP address.

  • What is DNS spoofing?

    DNS spoofing is a cyberattack where a hacker changes a DNS server to match a domain name with the wrong IP address, redirecting users to fake websites.

  • Why do IP addresses need to be hierarchical?

    IP addresses are hierarchical to organize and facilitate routing through the internet, similar to addressing for postal mails.

  • What is the role of an Internet Service Provider (ISP)?

    An ISP connects users to the internet, linking them to billions of devices worldwide.

  • Why was IPv6 developed?

    IPv6 was developed to provide more unique IP addresses than IPv4, which couldn't meet the growing demand.

  • How does the design philosophy of the internet help it adapt?

    The internet’s design philosophy allows it to adapt to new communication technologies by using a set of flexible protocols.

  • How are DNS servers organized?

    DNS servers are organized in a distributed hierarchy, dividing responsibility among major domains like .org, .com, and .net.

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  • 00:00:09
    Paola: Hi! My name is Paola, and I am a software  engineer here at Microsoft. Let’s talk about how
  • 00:00:15
    the internet works. My job relies on networks  being able to talk with one another, but back in
  • 00:00:22
    the 1970s, there was no standard method for this.  It took the work of Vint Cerf and Bob Kahn to
  • 00:00:30
    invent the internetworking protocol to make  communication possible. This invention laid the
  • 00:00:36
    groundwork for what we now call the internet. Vint: The internet is a network of networks.
  • 00:00:42
    It links billions of devices together all  around the globe. So maybe you’re connected
  • 00:00:47
    with a laptop or a phone through wifi, but  then that wifi connection connects to an
  • 00:00:53
    internet service provider (or ISP), and that ISP  connects you to billions and billions of devices
  • 00:00:59
    around the world through hundreds of thousands of  networks that are all interconnected. One thing
  • 00:01:06
    that most people do not appreciate is that the  internet is really a design philosophy and an
  • 00:01:12
    architecture expressed in a set of protocols.  A protocol is a well-known set of rules and
  • 00:01:18
    standards that, if all parties agree to use it,  will allow them to communicate without trouble.
  • 00:01:24
    How the internet actually physically works is  less important than the fact that this design
  • 00:01:30
    philosophy has allowed the internet to adapt  and absorb new communication technologies.
  • 00:01:36
    This is because in order for a new technology  to use the internet in some fashion, it just
  • 00:01:41
    needs to know which protocols to work with. Vint: All the different devices on the internet
  • 00:01:46
    have unique addresses. An address on the internet  is just a number, similar to a phone number or a
  • 00:01:52
    sort of street address, that’s unique to each  computer or device at the edge of the network.
  • 00:01:59
    This is similar to how most homes and businesses  have a mailing address. You don’t need to know a
  • 00:02:04
    person to send them a letter in the mail, but  you do need to know their address and how to
  • 00:02:08
    write the address properly so the letter can be  carried by the mail system to its destination.
  • 00:02:14
    The addressing system for computers  on the internet is similar,
  • 00:02:18
    and it forms part of one of the most important  protocols used in internet communication,
  • 00:02:23
    simply called the internet protocol (or IP).  A computer’s address, then, is called its IP
  • 00:02:29
    address. Visiting a website is really just your  computer asking another computer for information.
  • 00:02:35
    Your computer sends a message to  the other computer’s IP address,
  • 00:02:38
    and it also sends along its origin address, so the  other computer knows where to send its response.
  • 00:02:43
    Paola: You may have seen an IP address. It’s just  a bunch of numbers! These numbers are organized
  • 00:02:51
    in a hierarchy. Just like a home address has a  country, a city, a street, and a house number,
  • 00:02:58
    an IP address has many parts. Just like all  digital data, each of these numbers is represented
  • 00:03:05
    in bits. Traditional IP addresses are 32  bits long with 8 bits for each part of the
  • 00:03:12
    address. The earlier numbers usually identify  the country and regional network of the device.
  • 00:03:18
    Then come the subnetworks, and then finally the  address of the specific device. This version of
  • 00:03:25
    IP addressing is called IPv4. It was designed  in 1973 and widely adopted in the early 80s
  • 00:03:33
    and provides for more than 4 billion unique  addresses for devices connecting to the internet.
  • 00:03:39
    But the internet has turned out to be much  more popular than even Vint Cerf imagined,
  • 00:03:45
    and 4 billion unique addresses won’t  be enough. We’re now in the middle of a
  • 00:03:50
    multi-year transition to a longer IP address  format called IPv6 which uses 128 bits per
  • 00:03:58
    address and provides over 340 undecillion unique  addresses. That’s more than enough for every grain
  • 00:04:07
    of sand on Earth to have its own IP address. Vint: Most users never see or care about
  • 00:04:13
    internet addresses. A system called  the “domain name system” (or DNS)
  • 00:04:18
    associates names like www.example.com with the  corresponding addresses. Your computer uses the
  • 00:04:25
    DNS to look up domain names and get the associated  IP address, which is used to connect your
  • 00:04:30
    computer to the destination on the internet. (Then it goes a little somethin’ like this!)
  • 00:04:34
    Voice 1: Hey, hi there, I  want to go to www.code.org.
  • 00:04:38
    Voice 2: Mm… yeah I don’t know the, uh— the  IP address for that domain; let me ask around.
  • 00:04:46
    Hey, do you know how to get to, uh, code.org? Voice 3: Yeah, I got it right here;
  • 00:04:54
    it’s a 174.129.14.120. Voice 2: Oh, okay, great.
  • 00:05:01
    Thanks. Yeah I’m gonna— I’m gonna write that down  and save it for later in case I need it. Hey,
  • 00:05:05
    here’s that address you wanted. Voice 1: Awesome! Thank
  • 00:05:07
    you. Paola:
  • 00:05:13
    So how do we design a system for billions  of devices to find any one of billions of
  • 00:05:19
    different websites? There is no way one DNS server  can handle all the requests from all devices.
  • 00:05:27
    The answer is that DNS servers are connected in a  distributed hierarchy and are divided into zones,
  • 00:05:33
    splitting up responsibility for the major domains  such as .org, .com, .net, etc. DNS was originally
  • 00:05:43
    created to be an open and public communication  protocol for government and educational
  • 00:05:48
    institutions. Because of its openness, DNS is  susceptible to cyberattacks. An example attack is
  • 00:05:56
    DNS spoofing. That’s when a hacker taps into a DNS  server and changes it to match a domain name with
  • 00:06:04
    the wrong IP address. This lets the attackers send  people to an imposter website. If this happens to
  • 00:06:12
    you, you are vulnerable for more problems because  you are using that fake website as if it is real.
  • 00:06:21
    The internet is huge and getting bigger  every day, but the domain name system and
  • 00:06:27
    internet protocol are designed to scale,  no matter how much the internet grows.
标签
  • Internet
  • IP address
  • DNS
  • IPv4
  • IPv6
  • Cybersecurity
  • Communication protocol
  • Domain names
  • Network architecture
  • ISP