Learn what IPv4 is, how it works, its advantages, and limitations.
Introduction
When you connect to the internet, every device needs a unique identifier. That’s where IPv4 (Internet Protocol version 4) comes in. As one of the core technologies powering the web since the 1980s, IPv4 ensures that data travels across networks and reaches the right destination. Despite the rise of IPv6, IPv4 is still the most widely used protocol worldwide.
In this article, we’ll explain what IPv4 is, how it works, its limitations, and why IPv6 is slowly replacing it.
What is IPv4?
IPv4 stands for Internet Protocol version 4, the fourth version of the Internet Protocol. It uses a 32-bit address system, which allows for about 4.3 billion unique addresses.
Example of an IPv4 address:
192.168.1.1
Each IPv4 address consists of four sets of numbers (ranging from 0 to 255), separated by dots.
How IPv4 Works
IPv4 uses a system called packet-switching. When data is sent from one device to another:
- The data is broken into small packets.
- Each packet contains source and destination IP addresses.
- Routers read the addresses and forward the packets along the best path.
- The packets arrive at the destination and are reassembled.
Benefits of IPv4
- Simplicity – Easy to understand and implement.
- Compatibility – Supported by almost all devices, networks, and ISPs.
- Efficient Routing – Uses subnetting and CIDR (Classless Inter-Domain Routing).
- Broad Adoption – Still the backbone of most global internet traffic.
Limitations of IPv4
While IPv4 has served us well for decades, it comes with challenges:
- Limited Addresses – Only 4.3 billion addresses, which is not enough for today’s billions of devices.
- Security Concerns – Lacks built-in encryption.
- Dependence on NAT – Network Address Translation is used to extend IPv4, but it adds complexity.
IPv4 vs IPv6
| FeatureIPv4IPv6 | ||
| Address Length | 32-bit | 128-bit |
| Total Addresses | ~4.3 billion | ~340 undecillion |
| Example Address | 192.168.0.1 | 2001:0db8:85a3:0000:0000:8a2e:0370:7334 |
| Security | Optional (IPSec) | Built-in IPSec |
| Speed & Routing | Efficient | More efficient, simplified |
Is IPv4 Going Away?
Not anytime soon. While IPv6 adoption is increasing, IPv4 is still heavily used worldwide. In fact, most networks and ISPs run dual-stack systems, meaning they support both IPv4 and IPv6 simultaneously.
Conclusion
IPv4 has been the foundation of the internet for more than 40 years. Although its address limitations have led to the rise of IPv6, IPv4 remains critical for modern connectivity. Businesses, developers, and IT professionals should understand both IPv4 and IPv6 to future-proof their systems.