Routing

Summary

This video explains how digital information is routed across the internet. It begins by describing the role of IP addresses, including the transition from IPv4 to IPv6 due to address limitations. The Domain Name System (DNS) is introduced as a solution for mapping human-readable domain names to machine-readable IP addresses. The core concept of routing is discussed, where data is sent through a network of routers, which choose the best path based on factors like speed, reliability, and proximity. The system's fault-tolerance and scalability are highlighted, thanks to the redundancy in connections.

Takeaways

• 🌐 **Internet Communication**: The internet allows digital information to be sent from one device to another, enabling communication between computers.
• 🏷️ **IP Addresses**: Every device on the internet has a unique IP address, which acts as its identifier.
• 📈 **IPv4 to IPv6 Transition**: Due to the exhaustion of IPv4 addresses, the internet is transitioning to IPv6, which provides a much larger address space.
• 🔍 **DNS System**: DNS (Domain Name System) maps human-readable domain names to machine-readable IP addresses, simplifying web browsing.
• 🚦 **Routing**: Routing is the process that determines the path data takes to travel between two computers on the internet.
• 🌉 **Routers**: Routers are networking devices that forward data to its destination by choosing the best path from available options.
• 🛤️ **Path Selection**: Routers select the path based on a 'cost' calculation that considers factors like distance, reliability, and speed.
• 🔁 **Redundancy**: Multiple paths exist between any two points on the internet, providing redundancy and improving fault tolerance.
• 💡 **Reliability**: The redundancy in internet routing ensures that if one router fails, data can still reach its destination through alternative paths.
• 📈 **Scalability**: As more devices are added to the internet, the performance improves due to increased redundancy and reliability.

Q & A

What is the main purpose of the internet?

The main purpose of the internet is to facilitate the exchange of digital information between two computers, enabling them to communicate with each other.

How does a device get identified on the internet?

Every device on the internet is identified by a unique IP address.

What is the limitation of IPv4 addressing?

IPv4 has a limitation of only 4 billion unique addresses, which is insufficient for the growing number of devices on the internet.

What is IPv6 and how does it address the limitations of IPv4?

IPv6 is an updated version of the IP addressing system that uses more digits to represent addresses, providing over 30 undecillion unique addresses, which is sufficient for the foreseeable future.

Why do we need DNS when we have IP addresses?

We use DNS to map human-readable domain names to machine-readable IP addresses, making it easier for users to remember and access websites without having to remember complex strings of numbers.

What is routing and why is it necessary?

Routing is the process of sending data between two computers on the internet through routers that determine the most efficient path for the data to reach its destination.

How do routers decide the best path for data to take?

Routers decide the best path based on a cost calculation that considers factors like proximity to the destination IP address, reliability of the connection, and the speed of the connection.

Why is redundancy in internet routing important?

Redundancy in internet routing is important because it provides multiple paths between two points, improving the reliability and fault tolerance of the internet. If one router fails, data can still be routed through alternative paths.

How does the concept of 'cost' in routing differ from its common understanding?

In the context of internet routing, 'cost' does not refer to monetary value. Instead, it is a calculation based on factors like the proximity of the IP address, the reliability of the router, and the speed of the connection.

What happens if a router on the internet fails?

If a router fails, the system can still function because of the multiple paths available. Data can be rerouted through other routers, ensuring that communication is maintained.

How does the scalability of the internet benefit from the redundancy in routing?

The scalability of the internet benefits from redundancy in routing because as more routers are added to the network, it increases the reliability and performance of the system. More routers provide more paths and options for data to travel, improving overall efficiency.

Outlines

00:00

🌐 Introduction to Internet Routing

This paragraph introduces the concept of routing on the internet. It begins with a brief recap on how the internet works by transmitting digital information from one point to another. Every device on the internet is assigned a unique IP address, and the transition from IPv4 to IPv6 is highlighted due to the increasing number of devices. It discusses the role of the DNS system in translating human-readable domain names into machine-readable IP addresses, making web browsing more user-friendly.

05:04

📡 Routing Data Across the Internet

Here, the process of routing is introduced, where data is sent between computers over the internet using routers. Instead of direct connections between every device, routers act as intermediaries. Each computer connects to a router, which forwards data to its destination, creating a scalable system that supports millions of devices. This section lays the groundwork for understanding how computers communicate efficiently through a network of routers.

🔀 How Routers Determine the Path for Data

This paragraph explains how routers decide the best path for sending data. The process involves marking data with source and destination IP addresses. Routers calculate the 'cost' of forwarding the data based on factors like proximity to the destination, reliability, and connection speed. The router with the lowest cost forwards the message to the next router, repeating this process until the data reaches its final destination.

↔️ Sending a Response Back Across the Network

After receiving a message, the recipient computer writes a response and sends it back using the same routing process. Routers evaluate the best paths based on current conditions, possibly choosing different routes than the original message. This dynamic path selection is based on factors like connection speed and reliability, ensuring efficient communication between computers.

🔁 Redundancy and Fault Tolerance in Networks

This paragraph highlights the importance of redundancy in the internet. Having multiple possible routes between two points ensures that if one router fails or gets overloaded, the system continues to function using alternate paths. This redundancy makes the system fault-tolerant, improving its reliability and preventing single points of failure from disrupting communication.

📈 Scalability and Performance Benefits of Routing

The final paragraph discusses how adding more routers to the network not only increases reliability but also improves performance. As the system scales up with more routers, it enhances the overall capability of the internet, making it more robust and efficient. This scalability ensures the system can handle the increasing load as more devices connect to the network.

Keywords

💡IP Address

An IP (Internet Protocol) address is a unique identifier assigned to each device connected to the internet, allowing devices to locate and communicate with one another. In the video, IP addresses are explained as the core of routing, where each computer on the internet uses this address to send and receive data. For example, the script explains that IPv4 has a limitation on unique addresses, prompting a shift to IPv6 for scalability.

💡IPv4

IPv4 (Internet Protocol version 4) is an older addressing system for devices on the internet, providing about 4 billion unique addresses. The video highlights IPv4's limitation as more devices are connected to the internet, which is why the transition to IPv6 is necessary. It demonstrates the increasing demand for unique addresses with the rise of internet-connected devices.

💡IPv6

IPv6 (Internet Protocol version 6) is the latest addressing system, designed to replace IPv4 by offering a vastly larger pool of unique addresses (over 30 undecillion). The script explains that IPv6 allows for future growth, ensuring enough addresses for billions of devices expected to connect to the internet, thus solving the problem of IP address exhaustion.

💡DNS (Domain Name System)

DNS is a system that translates human-readable domain names (e.g., google.com) into machine-readable IP addresses. The video emphasizes that DNS simplifies browsing by allowing users to enter easy-to-remember domain names instead of long numeric IP addresses. For example, 'support.google.com' is mapped to its respective IP address through DNS.

💡Routing

Routing is the process of determining the path that data takes to travel between two devices on the internet. The video explains that routers direct data packets along the most efficient paths to reach their destination. These routers make decisions based on several factors like speed, reliability, and proximity to the final destination.

💡Router

A router is a device that forwards data between computer networks, directing packets of information to their destination. In the video, routers are critical components in the routing process, determining the optimal path based on various factors like connection speed and reliability. The video explains that routers help avoid direct connections between every device, which would not be scalable.

💡Redundancy

Redundancy refers to having multiple possible paths between two points in a network to ensure reliability and fault tolerance. The video explains that this is essential for making the internet scalable and resilient. If a router fails or a connection is lost, other paths can be used to send data, maintaining system stability.

💡Fault Tolerance

Fault tolerance is the ability of a system to continue functioning properly even when one or more components fail. The script highlights how the redundancy of paths between routers ensures that the internet can handle failures without collapsing. For instance, if one router fails, data can be rerouted through alternative paths, ensuring uninterrupted communication.

💡Cost

In the context of routing, 'cost' refers to a calculated metric used by routers to decide the best path for forwarding data. Cost can depend on factors like distance, connection speed, and reliability. The video mentions that routers choose routes with the lowest cost, which doesn’t always mean financial cost but instead refers to efficiency and performance, such as sending data over faster or more reliable connections.

💡Scalability

Scalability is the ability of a system to handle increased load or expansion without performance degradation. The video illustrates that the internet's design, with routers and redundancy, allows it to grow while improving performance. As more routers and devices are added, the system becomes more reliable and efficient, making it scalable and capable of supporting billions of devices.

Highlights

Routing is the process of sending data between two computers on the internet through routers that determine the data's route.

The internet is a massive network of routers connected in intricate ways to allow devices to communicate.

Each device on the internet has a unique IP address that helps in identifying and sending data to it.

IPv6 allows for over 30 undecillion unique addresses, resolving the limitations of IPv4's 4 billion address capacity.

DNS maps human-readable domain names to machine-readable IP addresses, making web browsing more user-friendly.

Routers forward data packets to other routers by calculating the 'cost' of each connection, considering distance, reliability, and speed.

The term 'cost' in routing refers to factors like proximity to the destination, reliability of the router, and connection speed, not financial cost.

Routers use the lowest 'cost' path to send data, optimizing the journey toward the final destination IP address.

Routing has redundancy, meaning there are multiple paths between two points, enhancing the internet's fault tolerance and reliability.

If a router fails or a path becomes unavailable, the system automatically reroutes data through alternative paths.

Redundancy in routing improves the system's reliability, ensuring it can still function even if individual routers fail.

Routing is scalable: adding more routers improves system reliability and performance by providing more paths for data transmission.

The fault tolerance of the internet ensures that even when routers are taken out by issues like overloading or natural disasters, communication continues.

The internet's routing system improves performance as more devices are added because it increases redundancy and fault tolerance.

Routing ensures that information is indirectly sent across a vast network of routers to reach its final destination efficiently.

Transcripts

hi in this video we'll be talking about routing  so let's recap a little bit so far we know that  

the internet is about getting digital information  from point A to point B we want to be able to send  

bits over a network so that two computers can talk  to each other now how do two computers find each  

other in this massive network well every device  on the internet has its own unique IP address  

now this is an old version of the IP addressing  system this is an ipv4 address the problem with  

ipv4 is there are only 4 billion unique addresses  and pretty soon we'll have well over four billion  

unique devices on the Internet so we're in the  process of switching to ipv6 which uses several  

more digits to represent a single address so  there are several more combinations several more  

possible addresses with ipv6 there's over 30 unda  Cillian unique addresses so we'll be fine for the  

foreseeable future now the problem is we don't  really want to be using these IP addresses when  

we're browsing the web we don't want to have to  remember all these massive strings of numbers  

so we use the DNS system to map domains to IP  addresses it's like an address book mapping human  

readable names to machine readable IP addresses  so we can have a domain like support google com  

that maps to this IP address or WWE just calm that  maps to that IP address and these names are a lot  

better for us to use so at this point we know  the destination we know we're in the internet  

were headed we have that IP address the question  is how do we make the journey how does information  

actually get to that destination well introducing  routing routing is the process of sending data  

between two computers on the internet the data is  sent through routers that determine the route that  

the data takes so in a simple network we need  a way for every computer to talk to every other  

computer rather than making individual wires  individual connections between each computer  

in the network what we do is we put in a router  so every computer just connects to the router and  

then if the computer on the bottom left wants  to talk to a computer on the top right it will  

just send that information along to the router  and the router will forward along the message  

this way we don't need connections going between  every single computer this isn't scalable when  

we start having millions billions of devices the  internet is just a larger version of this simple  

work to computers are connected through a massive  network of routers and these routers are connected  

in intricate ways so let's say these two computers  wanted to send messages to each other the computer  

on the left would write up a message and Mark it  with a from a dress and a to address it's from IP  

address to point to point to point to and sending  it to IP address nine point nine point nine point  

nine the computer before that message along  to the first router from here the router will  

look at all of its connections and forward on the  message to the router with the lowest cost and in  

this scenario cost doesn't mean least money spent  cost is actually a calculation of several things  

so cost is calculated based on how close is the  IP address of this router that I'm sending it to  

to the final destination is the router that I'm  sending it to trustworthy or has been failing a  

lot lately and is the connection fast am i sending  it over a fiber optic cable or am i sending it  

over or something like radio so it calculates the  connection with the lowest cost and forwards the  

message along to that router so let's say it  calculates that the top middle router has the  

lowest cost before that message along and then the  same process would repeat it would look at all of  

its connections and say what is the best place for  this message to go how is it getting closer to its  

final destination and is it reliable so let's say  it calculates the middle router on the final rail  

forwards it along there and now the message can  get all the way to its intended recipient so now  

the computer on the Left can read the message  it can write up a response and then send it  

back through the same process it marks it with  a from a dress and a to address and then using  

this destination IP address the routers will route  the message back to to point to point to point to  

so Ford this along to this computer maybe this  wrapper calculates that it's actually better to  

go to the bottom so we'll go there and then that  one might forward it along to this router that  

one might forward along to this router and finally  it gets forwarded to the final computer so that is  

how to computers can communicate with each other  now what's interesting to note is that there's a  

lot of redundancy here there are multiple paths  that exist between two points and this may seem  

redundant this may seem like extra work there's  too many connections but this is actually a good  

thing we don't want single connections between  every computer we want to have multiple paths  

because this in proves the reliability of the  internet this makes it so that the system is  

fault tolerant if an individual router breaks  which happens all the time the system doesn't  

stop working all together individual routers can  break left and right and the system still works  

fine so if you look at this this is only one of  many paths between these two computers if that  

router on top were to get overloaded or if it were  to crash or break or there was an earthquake and  

it just got taken out that's completely fine  because now we can use this path and maybe  

that bottom right one gets taken out that's fine  because we can use this path so this redundancy is  

a good thing it makes the system fault-tolerant  so improves reliability and it makes the system  

scalable a lot of times it's hard to create a  system that as you add load to it as you add  

a bunch of machines it still works in this case  adding more and more routers that actually makes  

the performance better because now we have even  more reliability and more redundancy so by scaling  

up we actually get better performance so this is  how information is sent across the internet it is  

routed in indirect ways through a vast network of  routers to get to its final destination IP address