IP Q&A
Everything you always wanted to know about IP addresses — what they are, how they came to be, and how IPv4 differs from IPv6.
An IP (Internet Protocol) address is a unique numerical label assigned to every device connected to a network that uses the Internet Protocol for communication. It works like a postal address for your device, allowing data to be routed to and from it correctly across the internet.
IP addresses originated in the early 1970s as part of the ARPANET project funded by the US Department of Defense. The Internet Protocol was formally defined in RFC 791 in 1981, and the Internet Assigned Numbers Authority (IANA) was later established to manage the global allocation of address blocks.
IPv4 (Internet Protocol version 4) is the fourth version of the Internet Protocol and still the most widely used today. It uses a 32-bit address format written as four numbers separated by dots (e.g. 192.168.1.1), allowing for about 4.3 billion unique addresses.
IPv6 (Internet Protocol version 6) is the newest version of the Internet Protocol, designed to replace IPv4. It uses a 128-bit address format written as eight groups of hexadecimal digits separated by colons (e.g. 2001:0db8::1), providing a virtually unlimited number of unique addresses.
The main difference is address space: IPv4 offers about 4.3 billion addresses, while IPv6 offers roughly 340 undecillion. IPv6 also brings built-in improvements such as simplified routing and better support for security, and it removes the need for NAT in most cases.
A public IP address is visible on the internet and is assigned to your router by your Internet Service Provider. A private IP address is used only within a local network, such as your home Wi-Fi, and is not directly reachable from the internet.
A static IP address stays the same every time you connect, while a dynamic IP address is assigned temporarily by your ISP and can change periodically. Most home internet connections use dynamic IP addresses.
An IP address can reveal an approximate location — typically your city or region — based on data provided by your ISP. It cannot reveal your exact street address, your name, or other personal details.
In many jurisdictions, including under the EU's GDPR, an IP address can be considered personal data because, combined with other information, it may be used to identify an individual.
You can hide your real IP address by using a VPN (Virtual Private Network) or a proxy server, which routes your traffic through a different server. Restarting your router or contacting your ISP can also change a dynamic IP address.
NAT is a method routers use to let multiple devices on a private network share a single public IP address. It translates private addresses into a public one when devices access the internet, and back again for incoming traffic.
IPv4's roughly 4.3 billion addresses have been largely exhausted due to the massive growth of internet-connected devices worldwide. IPv6 was created to solve this shortage, providing effectively unlimited addresses for the growing number of smartphones, computers and IoT devices.