Routing
Summary
TLDRThis 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
- š **Internet Communication**: The internet allows digital information to be sent from one device to another, enabling communication between computers.
- š·ļø **IP Addresses**: Every device on the internet has a unique IP address, which acts as its identifier.
- š **IPv4 to IPv6 Transition**: Due to the exhaustion of IPv4 addresses, the internet is transitioning to IPv6, which provides a much larger address space.
- š **DNS System**: DNS (Domain Name System) maps human-readable domain names to machine-readable IP addresses, simplifying web browsing.
- š¦ **Routing**: Routing is the process that determines the path data takes to travel between two computers on the internet.
- š **Routers**: Routers are networking devices that forward data to its destination by choosing the best path from available options.
- š¤ļø **Path Selection**: Routers select the path based on a 'cost' calculation that considers factors like distance, reliability, and speed.
- š **Redundancy**: Multiple paths exist between any two points on the internet, providing redundancy and improving fault tolerance.
- š” **Reliability**: The redundancy in internet routing ensures that if one router fails, data can still reach its destination through alternative paths.
- š **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
š 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.
š” 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.
š 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.
āļø 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.
š 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.
š 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.
Mindmap
Keywords
š”IP Address
š”IPv4
š”IPv6
š”DNS (Domain Name System)
š”Routing
š”Router
š”Redundancy
š”Fault Tolerance
š”Cost
š”Scalability
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 routingĀ so let's recap a little bit so far we know thatĀ Ā
the internet is about getting digital informationĀ from point A to point B we want to be able to sendĀ Ā
bits over a network so that two computers can talkĀ to each other now how do two computers find eachĀ Ā
other in this massive network well every deviceĀ on the internet has its own unique IP addressĀ Ā
now this is an old version of the IP addressingĀ system this is an ipv4 address the problem withĀ Ā
ipv4 is there are only 4 billion unique addressesĀ and pretty soon we'll have well over four billionĀ Ā
unique devices on the Internet so we're in theĀ process of switching to ipv6 which uses severalĀ Ā
more digits to represent a single address soĀ there are several more combinations several moreĀ Ā
possible addresses with ipv6 there's over 30 undaĀ Cillian unique addresses so we'll be fine for theĀ Ā
foreseeable future now the problem is we don'tĀ really want to be using these IP addresses whenĀ Ā
we're browsing the web we don't want to have toĀ remember all these massive strings of numbersĀ Ā
so we use the DNS system to map domains to IPĀ addresses it's like an address book mapping humanĀ Ā
readable names to machine readable IP addressesĀ so we can have a domain like support google comĀ Ā
that maps to this IP address or WWE just calm thatĀ maps to that IP address and these names are a lotĀ Ā
better for us to use so at this point we knowĀ the destination we know we're in the internetĀ Ā
were headed we have that IP address the questionĀ is how do we make the journey how does informationĀ Ā
actually get to that destination well introducingĀ routing routing is the process of sending dataĀ Ā
between two computers on the internet the data isĀ sent through routers that determine the route thatĀ Ā
the data takes so in a simple network we needĀ a way for every computer to talk to every otherĀ Ā
computer rather than making individual wiresĀ individual connections between each computerĀ Ā
in the network what we do is we put in a routerĀ so every computer just connects to the router andĀ Ā
then if the computer on the bottom left wantsĀ to talk to a computer on the top right it willĀ Ā
just send that information along to the routerĀ and the router will forward along the messageĀ Ā
this way we don't need connections going betweenĀ every single computer this isn't scalable whenĀ Ā
we start having millions billions of devices theĀ internet is just a larger version of this simpleĀ Ā
work to computers are connected through a massiveĀ network of routers and these routers are connectedĀ Ā
in intricate ways so let's say these two computersĀ wanted to send messages to each other the computerĀ Ā
on the left would write up a message and Mark itĀ with a from a dress and a to address it's from IPĀ Ā
address to point to point to point to and sendingĀ it to IP address nine point nine point nine pointĀ Ā
nine the computer before that message alongĀ to the first router from here the router willĀ Ā
look at all of its connections and forward on theĀ message to the router with the lowest cost and inĀ Ā
this scenario cost doesn't mean least money spentĀ cost is actually a calculation of several thingsĀ Ā
so cost is calculated based on how close is theĀ IP address of this router that I'm sending it toĀ Ā
to the final destination is the router that I'mĀ sending it to trustworthy or has been failing aĀ Ā
lot lately and is the connection fast am i sendingĀ it over a fiber optic cable or am i sending itĀ Ā
over or something like radio so it calculates theĀ connection with the lowest cost and forwards theĀ Ā
message along to that router so let's say itĀ calculates that the top middle router has theĀ Ā
lowest cost before that message along and then theĀ same process would repeat it would look at all ofĀ Ā
its connections and say what is the best place forĀ this message to go how is it getting closer to itsĀ Ā
final destination and is it reliable so let's sayĀ it calculates the middle router on the final railĀ Ā
forwards it along there and now the message canĀ get all the way to its intended recipient so nowĀ Ā
the computer on the Left can read the messageĀ it can write up a response and then send itĀ Ā
back through the same process it marks it withĀ a from a dress and a to address and then usingĀ Ā
this destination IP address the routers will routeĀ the message back to to point to point to point toĀ Ā
so Ford this along to this computer maybe thisĀ wrapper calculates that it's actually better toĀ Ā
go to the bottom so we'll go there and then thatĀ one might forward it along to this router thatĀ Ā
one might forward along to this router and finallyĀ it gets forwarded to the final computer so that isĀ Ā
how to computers can communicate with each otherĀ now what's interesting to note is that there's aĀ Ā
lot of redundancy here there are multiple pathsĀ that exist between two points and this may seemĀ Ā
redundant this may seem like extra work there'sĀ too many connections but this is actually a goodĀ Ā
thing we don't want single connections betweenĀ every computer we want to have multiple pathsĀ Ā
because this in proves the reliability of theĀ internet this makes it so that the system isĀ Ā
fault tolerant if an individual router breaksĀ which happens all the time the system doesn'tĀ Ā
stop working all together individual routers canĀ break left and right and the system still worksĀ Ā
fine so if you look at this this is only one ofĀ many paths between these two computers if thatĀ Ā
router on top were to get overloaded or if it wereĀ to crash or break or there was an earthquake andĀ Ā
it just got taken out that's completely fineĀ because now we can use this path and maybeĀ Ā
that bottom right one gets taken out that's fineĀ because we can use this path so this redundancy isĀ Ā
a good thing it makes the system fault-tolerantĀ so improves reliability and it makes the systemĀ Ā
scalable a lot of times it's hard to create aĀ system that as you add load to it as you addĀ Ā
a bunch of machines it still works in this caseĀ adding more and more routers that actually makesĀ Ā
the performance better because now we have evenĀ more reliability and more redundancy so by scalingĀ Ā
up we actually get better performance so this isĀ how information is sent across the internet it isĀ Ā
routed in indirect ways through a vast network ofĀ routers to get to its final destination IP address
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