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20th August 2020

What is an IP address?

What is an IP address?

Your IP (internet protocol) address is a unique string of numbers that is given to each of your devices that connect to the internet, like your laptop and mobile phone. The number acts as the address for your device, so that things communicating with your device know where to send the response. Without an IP address, devices would not be able to communicate with each other. 

What is the meaning of an IP address?

The easiest way to think of an IP address is the same as a house address. By having an IP address, you are able to send and receive information to your device specifically. 

To most people, an IP address will look like a random series of numbers separated by full stops. But there is a method behind the madness. Let’s take a closer look … 

IP address example

Below is a common example of an IP address:

First of all, there are two parts to an IP address:

  • Network ID – a common address that is shared by a number of devices (think: the name of your road). In the example above, this would be 192.168.

  • Host ID – a unique address for your device (think: the number of your house/apartment). In the example above, this would be 0.1.

IP addresses use a binary numbering system – which only uses 0 and 1 – with an IP address consisting of a 32-bit binary number. To make it easier to understand, the 32-bit binary number is broken down into four 8-bit units (called octets). But to make it easy for humans to read and understand, the IP address is then converted from binary to decimal – with full stops in between each of the numbers to separate the numbers. 

How does a device get an IP address?

OK, so now we know what an IP address is, what it looks like and why we need one. How does a device go about getting an IP address? 

For the vast majority of people, your router or modem will automatically assign your device an IP address from your Internet Service Provider using Dynamic Host Configuration (DHCP) technology. These assigned IP addresses are known as ‘dynamic’ IP addresses – that’s because they can change periodically and are not fixed. 

A static IP address is one that never changes and is used by internet stalwarts like large, popular websites or email services. 

But for most of us, getting an IP address is something that we don’t have to think about – your device will automatically be assigned one in order to connect and use the internet. 

What is my IP address?

If you need to know your IP address, there are a few simple things that you can do to find it out. 

If you are on Windows 10:

  • Open the taskbar and select Wi-Fi network > the name of the Wi-Fi network you are connected to > Properties 

  • Under Properties, your IP address will be listed next to the IPv4 address.   

If you are on Mac:

  • Open System Preferences > Network

  • Click the connection on the left with the green light. The IP address will be listed under Status. 

If you are on an Android device: 

  • Open Settings > About phone

  • The IP address should be listed near the bottom. 

If you are on an iOS device:

  • Open settings > Wi-Fi > tap the blue ‘i’ icon

  • The IP address will be listed in the menu.

Or, you can just Google ‘what is my IP address’ and Google will automatically list it as a search result. 

IPv4 and IPv6

To make matters a little more complicated, there is a new version of the internet protocol – the ‘IP’ in your IP address. This new version is called IPv6 and it’s here to replace IPv4 – which a large amount of the internet still uses. 

You see, IPv4 has a theoretical maximum of around four billion unique combinations. This was more than enough when IPv4 was first conceived but, given today’s connected world, that is no longer enough. Remember, each device connected to the internet needs a unique IP address in order to send and receive information. IPv6 addresses are 128-bits long, a huge increase from IPv4’s 32-bit long addresses. What this means is that there are a theoretical 340 undecillion (a number with 36 zeros) IP addresses with IPv6 – enough for every person on the planet to have more than a million devices each! 

What can someone do with your IP address?

The vast majority of the time, you will not have to worry about your IP address. But it is feasible that someone could find out your IP address and use that information to find out more about you. That includes a rough geographical location – which can be unsettling if you want to remain private and anonymous. 

For example, most dynamic IP addresses assigned to devices are based on a real-world location. That means that companies and services can tailor localised content to you based on your IP address. 

But what if your IP address gets into the wrong hands? By itself, your IP address isn’t too valuable to hackers. But a dedicated hacker could potentially work out your Internet Service Provider from your IP address and then carry out a phishing attack to try and obtain your personal information – but this is a very rare occurrence. 

If you are concerned about your IP address falling into the wrong hands, you can hide it by using a VPN. Read more about VPNs here.  

Is it illegal to look up someone’s IP address in the UK? 

It is not actually illegal to look up someone’s IP address in the UK. That’s because, by itself, your IP address is not considered personal data under the Data Protection Act. It’s only when an IP address is combined with other personal information like name and address that it falls under the Data Protection Act. 

Does my IP address change every time I connect to the internet? 

If you are using a static IP address then your IP address will always stay the same. Most of us will have a dynamic IP address that is automatically allocated to us – but that doesn’t necessarily mean that your IP address will change every time you connect to the internet. That’s because each dynamic IP address will have a lease term. After the lease term expires, you will be assigned another IP address. 

Interested in a static IP address? Read more here

Can I hide my IP address?

If you are not comfortable with companies or individuals knowing your IP address, there are ways of masking your IP address. The easiest and most effective way is to use a virtual private network (VPN). A VPN protects you by masking your IP address – making it impossible for someone to find out your IP address.

Does my mobile phone have an IP address?

Even if your mobile phone is connected using mobile data, it will still have an IP address. The vast majority of networks in the UK will assign a dynamic IP address to your mobile which will change when the lease term expires.