I'm feeling rather proud of myself. After a conversation with someone yesterday, I installed ESXi on my home built computer. I was concerned at first, as it wasn't connecting to the internet... but then I realized that I didn't have a physical ethernet cable plugged in and had been relying on the wireless NIC. I plugged the cable in this morning, and it's working fine. I even managed to access it from another computer. So now I'm downloading some files necessary for creating virtual machines, so I can try creating a virtual lab to mess around in.
Anyways. Today I wanted to talk a bit about the internet. The usual place to start is with a rather technical discussion, but I'm trying to translate these concepts into everyday language, so I'm going to try something different. Understand that I am vastly oversimplifying some things, and skipping over a lot of detail here.
With that out of the way, let's talk about the internet.
Actually, let's start with something most people are more comfortable with - tracking a package.
Whether it's USPS, DHL, UPS, or Amazon, every carrier will show the progress of a package as it moves from it's source to it's destination. I think most people understand what is going on here without thinking about it too much, either.
That is, the carrier isn't going to send your mail directly from one place to another. There's too much mail going to too many places and if you need that to happen, you'd hire a courier to do the job.
Instead, the post office (and other such carriers) regularly carry mail to nearby facilities, and will route everything they receive to the facility best suited for sending that mail on to it's final destination. As you can see in the picture above, the package goes from Chicago to Indianapolis before going to Fort Wayne. Indianapolis is a bit further south than Fort Wayne, so routing it this way added a bit more time than sending it directly to Fort Wayne, but there probably isn't enough mail going to straight to Fort Wayne to warrant a direct connection... so Indy was the closest place along the way (and much closer then sending the mail to St. Louis!).
It's all done for the same reason airlines have hubs, and it's difficult to get a flight straight to your destination unless you live at one of those hubs, and are going straight to another hub.
The internet is a bit like that, as well. When you get on an internet browser and put in a location, the page you're looking for is not floating out there in the digital aether. It's sitting on a computer somewhere. (Okay, so it might be sitting on a virtual machine, with twenty other virtual machines... but those are all sitting on a physical machine somewhere. Ultimately, everything you do on the internet is tied to a real, physical place.)
If you want to go see funny cats, and you put https://icanhas.cheezburger.com/lolcats in the browser, that /lolcats indicates a subdirectory where the file is stored, much like you might find a picture by going to C:\Users\Yourname\Pictures.
Your internet browser will send a request for the webpage to the site (called a 'server', since it serves webpages to whoever asks) and that site will send you the information you requested. The browser knows how to read the result and present it to us with all the fonts, colors, and pictures the creator intended.
Although the internet works a bit like the postal service, there are also (numerous) key differences. For one thing, a post office generally stays open for years. Decades even. Carrier routes are somewhat stable, and any significant changes tend to be advertised well in advance.
In contrast, routers may appear and disappear on the internet in the blink of an eye. Someone may add a router in one location, and another might break down and go off the net. So the routers, or 'sorting facilities' of the post office, regularly send out messages to their neighbors going "Are you still there?"
And whenever a new router comes online, it sends out messages to all its neighbors saying "Tadah! I AM HERE!"
The sorting facilities constantly have to update their routing information to take into account any sudden loss of connection, and they have to sense whether their neighbor is getting flooded with mail so they can lighten the load a bit and route things to a different facility.
There are other differences as well, such as size limits. If you wanted to send a letter, or mail a package, most of the time you can do it all at once. And when you send it, you can send it off and forget about it, relying on the carrier to get it where it needs to be. (Like UDP, an internet protocol that fires and forgets.)
That won't work for certain things, though I'm editing to say video is UDP, because waiting for confirmation slows it down too much. Web pages and file transfers are TCP, since you want to make sure everything arrives.
Anyways. Today I wanted to talk a bit about the internet. The usual place to start is with a rather technical discussion, but I'm trying to translate these concepts into everyday language, so I'm going to try something different. Understand that I am vastly oversimplifying some things, and skipping over a lot of detail here.
With that out of the way, let's talk about the internet.
Actually, let's start with something most people are more comfortable with - tracking a package.
Whether it's USPS, DHL, UPS, or Amazon, every carrier will show the progress of a package as it moves from it's source to it's destination. I think most people understand what is going on here without thinking about it too much, either.
That is, the carrier isn't going to send your mail directly from one place to another. There's too much mail going to too many places and if you need that to happen, you'd hire a courier to do the job.
Instead, the post office (and other such carriers) regularly carry mail to nearby facilities, and will route everything they receive to the facility best suited for sending that mail on to it's final destination. As you can see in the picture above, the package goes from Chicago to Indianapolis before going to Fort Wayne. Indianapolis is a bit further south than Fort Wayne, so routing it this way added a bit more time than sending it directly to Fort Wayne, but there probably isn't enough mail going to straight to Fort Wayne to warrant a direct connection... so Indy was the closest place along the way (and much closer then sending the mail to St. Louis!).
It's all done for the same reason airlines have hubs, and it's difficult to get a flight straight to your destination unless you live at one of those hubs, and are going straight to another hub.
The internet is a bit like that, as well. When you get on an internet browser and put in a location, the page you're looking for is not floating out there in the digital aether. It's sitting on a computer somewhere. (Okay, so it might be sitting on a virtual machine, with twenty other virtual machines... but those are all sitting on a physical machine somewhere. Ultimately, everything you do on the internet is tied to a real, physical place.)
If you want to go see funny cats, and you put https://icanhas.cheezburger.com/lolcats in the browser, that /lolcats indicates a subdirectory where the file is stored, much like you might find a picture by going to C:\Users\Yourname\Pictures.
Your internet browser will send a request for the webpage to the site (called a 'server', since it serves webpages to whoever asks) and that site will send you the information you requested. The browser knows how to read the result and present it to us with all the fonts, colors, and pictures the creator intended.
Although the internet works a bit like the postal service, there are also (numerous) key differences. For one thing, a post office generally stays open for years. Decades even. Carrier routes are somewhat stable, and any significant changes tend to be advertised well in advance.
In contrast, routers may appear and disappear on the internet in the blink of an eye. Someone may add a router in one location, and another might break down and go off the net. So the routers, or 'sorting facilities' of the post office, regularly send out messages to their neighbors going "Are you still there?"
And whenever a new router comes online, it sends out messages to all its neighbors saying "Tadah! I AM HERE!"
The sorting facilities constantly have to update their routing information to take into account any sudden loss of connection, and they have to sense whether their neighbor is getting flooded with mail so they can lighten the load a bit and route things to a different facility.
There are other differences as well, such as size limits. If you wanted to send a letter, or mail a package, most of the time you can do it all at once. And when you send it, you can send it off and forget about it, relying on the carrier to get it where it needs to be. (Like UDP, an internet protocol that fires and forgets.)
That won't work for certain things, though I'm editing to say video is UDP, because waiting for confirmation slows it down too much. Web pages and file transfers are TCP, since you want to make sure everything arrives.
The size limit means your letter might need to be broken down into 20 letters, and those letters might get routed differently... so letter 18 might arrive at its destination before letter 12. And letter 13 might fall into a puddle, and be completely unreadable. The letters have to be sent and received in a timely fashion, and put in order. Otherwise you'll get lag, and bits of the video will be missing.
So you need mechanisms for keeping track of what order the letters were sent, you need to verify that all the letters were actually received correctly (and that any missing letters are resent), and the letters ought to be sealed so that you know if someone got in and tampered with it.
And so on, and so forth. You can get into the nitty gritty details on how this is managed if you want, there are plenty of resources out there.
So you need mechanisms for keeping track of what order the letters were sent, you need to verify that all the letters were actually received correctly (and that any missing letters are resent), and the letters ought to be sealed so that you know if someone got in and tampered with it.
And so on, and so forth. You can get into the nitty gritty details on how this is managed if you want, there are plenty of resources out there.
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