What is IPv4?

IPv4 (Internet Protocol version 4) is the most common system that gives every device on the internet a unique numeric address, like a phone number, so they can find and talk to each other. It uses a 32-bit number written as four groups of numbers separated by dots (e.g., 192.168.0.1).

Let's break it down

  • Internet Protocol: a set of rules that tell computers how to send data to each other.
  • Version 4: the fourth major version of these rules; the one most people still use today.
  • 32-bit number: a string of 32 binary digits, which can be shown as four decimal numbers (0-255) separated by periods.
  • Unique address: each device gets its own number so data knows where to go, just like a mailing address.

Why does it matter?

Without IPv4 (or a similar system), computers wouldn’t know where to send emails, web pages, or video calls. It’s the backbone that makes everyday internet activities possible and reliable.

Where is it used?

  • Home Wi-Fi routers assigning local addresses to phones, laptops, and smart TVs.
  • Websites and online services using IPv4 addresses to be reachable by browsers.
  • Corporate networks that connect office computers, printers, and servers.
  • Mobile networks that give smartphones an IPv4 address for internet access.

Good things about it

  • Simple and well-understood; almost every device and software supports it.
  • Works with existing infrastructure, so no major upgrades are needed.
  • Efficient for most everyday tasks; low processing overhead.
  • Wide compatibility across different operating systems and hardware.
  • Large pool of publicly documented tools for troubleshooting and management.

Not-so-good things

  • Limited address space (about 4.3 billion addresses) leading to shortages as more devices connect.
  • Lack of built-in security features; relies on additional protocols for protection.
  • Inefficient routing in some cases compared to newer protocols like IPv6.
  • Complex workarounds (NAT, CIDR) are needed to stretch the limited address pool.