IP-addressing Simply Explained
IP-addressing sits at the heart of networking. We have currently been using IPv4 (the acronym stands for Internet Protocol version 4), but since all the addresses are running out quickly, we will be switching over to IPv6 in the future. So what are they?
Let’s look a little deeper into what the IP-address really is, what is its role in browsing the web, and how are we already running out of available addresses.
What is it and why I need one?
To start off — the Internet Protocol (IP) is just a set of rules that help different devices to talk to each other. IP addresses, in short, make it possible for all the billions of devices in the world to connect to each other. You could compare them to physical addresses that our homes have. If you want to send a letter to a friend in France, it’s not enough if you just write their name on the envelope. You need to write down their exact address, zip code and country. When little bits of data get sent, the IP-addresses are used to get the data to the right place.
An IPv4 address consist of four numbers (called octets) that are separated by dots, all ranging from 0 to 255.
Why only up to 255? Because every octet is made up of 8 bits (a bit can either be “on” or “off”/ zero or one) and if they are all “on”, their sum is 255.
11111111.1111111.1111111.11111111 = 255.255.255.255
Those four octets offer about 4.3 billion unique addresses. It might seem like a lot, but is it really?
When the IPv4 was created, that amount seemed absurdly big. Then the Internet exploded and everyone wanted a piece of that pie.
There are currently over 7 billion people in the world – we don’t even have enough addresses to give each person their own device with a unique address. Now, how many devices do you have? Most of us have a laptop or PC, smartphone, maybe a tablet, e-reader, smart TV… you get the point.
So how come have we not run out of addresses yet? The answer is dynamic IP-addresses. Your Internet Service Provider has something called a DHCP (Dynamic Host Configuration Protocol) server, which assigns IP-addresses automatically. That means you don’t have one specific number assigned to you (unless you have done so manually), but an address that happens to be available at that moment. Every time you connect to the internet, the server finds you an IP that isn’t being used at that moment. PS: this doesn’t mean that you are untraceable.
But even when using DHCP, we are awfully short on addresses.
The future is here
This is where IP version 6 comes along. Instead of having 4 numbers, IPv6 instead has four hexadecimal digits in eight groups, so a usual IPv6 address would look something like this: 2001:0db8:0000:0042:0000:8a2e:0370:7334.
So what’s with the letters in between numbers? Well, hexadecimal numbers go up to 9, and everything over the number 9, you must use letters starting from the first letters of the alphabet. So 10 would be A, 11 would be B, etc. all the way up to F (which represents 15).
Now you might be wondering, how many IP-addresses are available with the new version of IP?
The amount of addresses is a modest 42 undecillion. For normal people, that is
devices with a unique address. For comparison, we could assign an IPv6 address to every atom on the surface of the Earth, and we would still have as many left to assign addresses to atoms of another 100+ Earths. That should last us for quite some time…
Now you might be wondering, is switching over to IPv6 something I should be worried about? Well, not really. Not all websites are using IPv6 yet, and most websites that are will also support IPv4. The process of switching over to the next version will be gradual and just something to keep in the back of your head.
Now you can give yourself a pat on the back – you understand (a little about) how data gets sent over the network.
What's your IP?
You can check out your IP-address two different ways –
- You can just visit the site http://www.whatsmyip.org/, or
- You can open your command prompt and check there. Here’s how you can do that:
- For Windows: click on the Start menu and type in “cmd” (for “command line”). When you are in the command prompt, type in “ipconfig”. You can find your IP-address under the IPv4 address line.
- For Mac: Click on the Apple icon on the upper-left corner and choose “System Preferences”. Click “Network” and choose your connection. You should see your IP-address in the IP Address line.
Please note that the IP-address you get from the website and the IP you get from the command line will differ. That is because the web browser will give you your public IP – the one that the world sees – kind of like your house number. The IP you see through the command line is your private IP, which is meant to send and receive data inside your network. You can think of it like a room in the house. If someone in your house gets a letter that is addressed for you, they will know to deliver it to your room.
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