Basic Computer Networking: IP Addressing, DNS, and NAT

Your ability to hop onto the internet or connect to other devices largely hinges on the magic of computer networking. This connectivity is all thanks to IP addresses and the Domain Name System, or DNS for short.

Think of the internet as a bustling city, full of buildings, millions of them, and you have one letter to post, to find the right place you just read the address.

An IP address is the same as the street address for every house, building, or apartment. It uniquely identifies its way to the right computer, just like a letter to the correct mailbox.

Now, remembering a string of numbers for every site you want to visit isn’t what we humans do. We can remember things like google.com much easier.

That’s where DNS steps in, functioning like a phonebook for the internet.

Instead of dialing a friend’s number from memory, you would have searched for their name in the phonebook. So google.com is the name, which is called a domain in the computer world.

So the Domain Name System, or Domain Name Server (people differ on how they want to call it, probably why they shortened it to DNS) is basically a big computer with a list of domain names that correspond to IP addresses.

So when you type in google.com, the DNS converts this to the numerical IP address that computers understand and connects you to the website.

Understanding these basics is not just for IT professionals; it’s useful for anyone who uses the internet. Knowing about IP addresses and DNS can help you troubleshoot network issues, protect your privacy, and get a clearer perspective on how daily online interactions work.

So, as you dive into the worlds of IP addresses and DNS, you’re gaining vital knowledge that demystifies the processes that make the internet function smoothly.

Fundamentals of Networking

The video above is of Network Chuck, a very talented guy who taught me so much about networking when I was learning how to become a network professional. His videos are entertaining too, and like me, he loves coffee.

What Is an IP Address?

An IP address is a unique identifier assigned to each device connected to a network.

There are two versions of IP addresses:

• IPv4: This is a 32-bit number, typically seen as four groups of numbers separated by periods, like 192.168.1.1.
• IPv6: With the web growing, we needed more addresses, so IPv6 came into play. It’s 128 bits, shown as eight groups of four hexadecimal digits, like 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

I thought IPv4 numbers were hard to remember, and when IPv6 was introduced, I was so thankful for DNS.

Understanding DNS

To better explain how DNS works, it is easier to split it into different stages:

1. You type in google.com on your computer, and it then sends a request to a DNS server to match the corresponding IP address with the domain name it has.
2. The DNS server gets the request from your computer and looks through its records to find the IP address for the domain name you entered.
3. Once found, it sends back the IP address to your computer.
4. Your computer can then use this IP address to communicate with the desired server, in this case, google.com, and then it pops up on your screen.

When I learned this, it blew my mind.

All this happens in fractions of a second, and the DNS could be miles away from you. It takes me a while to get out of bed, so this is incredible to me.

Network Address Translation – NAT

All homes and businesses have 2 types of IP addresses, a public address and a private address.

You have one public IP address (unless you pay for more), supplied by your internet service provider (ISP), but each device in your home or business has its own IP address supplied by your router.

To try to explain this, I’m going to use the pizza analogy because I love pizza.

Imagine you live in a big house with lots of rooms, and you have one mailbox out front. Every time you want to send a letter or receive one, it has to go through that mailbox, right?

Now, let’s say everyone in your house wants to order pizza from different places, but they all have to use that one mailbox to get their orders out and the pizzas delivered.

Network Address Translation is like your house’s mailbox for the internet in your home network.

Your home has many devices like phones, tablets, and laptops (these are like the people wanting pizza). But on the internet, your whole home looks like it has just one address—like having one mailbox for all those pizza orders.

When one of your devices sends something out to the internet, NAT is like a smart mailman that takes your letter, notes down who it’s from, and puts the house’s single address on it.

When responses come back (like pizza deliveries), NAT remembers who in the house asked for it and makes sure it gets to the right room, or in this case, the right device.

So, NAT helps all your devices share the single internet address your home has, making sure everyone gets their internet “pizza” delivered correctly, without mixing up orders.

Plus, it helps keep things a bit safer, because the outside world only sees that one address, not all the separate devices you have.

Connecting to the Router

Connecting to your router can be as smooth as butter, or so infuriating that you want to throw it up the wall.

There are 2 ways to connect, wired or wireless.

Wired

Just connect one end of the ethernet cable to the router, and the other end to your computer. Simple, am I right?

Wrong!

Most modern laptops no longer have an ethernet port, so you have to buy a USB to ethernet adaptor just to connect to the router, meaning even more expense.

You can also very easily break the plastic retaining clip (which I call a tang because when you flick the clip it makes a TANG noise). This is even more infuriating, as the cable works, but it keeps falling out of the socket.

Wireless (Wi-Fi)

You can connect to wireless internet in 7 simple steps:

1. Grab Your Device: This could be your smartphone, tablet, laptop, or even a smart fridge if you’re fancy like that.
2. Find the WiFi Settings: If you’re on a smartphone or tablet, swipe down from the top (Android) or up from the bottom (iOS) look for the WiFi symbol, and tap on it. On a computer, you’ll usually find this symbol down in the bottom right corner (Windows) or the top right corner (Mac).
3. The Hunt for Networks: Once you tap or click on that WiFi symbol, your device will start looking for WiFi networks. You’ll see a list of names, which are all the WiFi networks around you. Some might belong to your neighbors, and others might be yours. Hopefully, you know your network’s name. If not, look for it on the back or underneath your router.
4. Choose Your Network: Tap on your WiFi network’s name from the list.
5. Enter the Secret Code: No, it’s not “Open Sesame,” but your WiFi password. This is what keeps your neighbors from streaming movies on your dime. Type in the password carefully, making sure you adhere to any case changes of letters.
6. Wait for the Magic: Hit connect and watch the magic happen. Your device will think for a bit, and if you’ve got everything right, it’ll connect you to the WiFi. You’ll see those WiFi bars light up, giving you the thumbs up that you’re connected.
7. You’re In!: Now you can stream, browse, download, or even order pizza online. The digital world is your oyster!

And that’s it! You’ve conquered the digital divide and connected to WiFi. Give yourself a high-five, and go enjoy the wonders of the internet.