What is IPv6?

IPv6 (Internet Protocol version 6) is the newest system that gives every device on the internet a unique address, replacing the older IPv4 system. It uses longer, hexadecimal addresses so there are enough numbers for all the devices we’ll ever need.

Let's break it down

  • Internet Protocol (IP): the set of rules that lets computers find and talk to each other online.
  • Version 6: the sixth major version of those rules; the previous one was version 4 (IPv4).
  • Address: a label (like a street address) that tells where a device is on the network.
  • Hexadecimal: a base-16 number system (0-9 and A-F) used because it can represent large numbers more compactly.
  • Longer address: IPv6 uses 128 bits (about 3.4 × 10³⁸ possible addresses) instead of IPv4’s 32 bits (about 4 billion addresses).

Why does it matter?

Because the world now has billions of smartphones, smart-home gadgets, and IoT devices, the old IPv4 address pool is running out. IPv6 ensures every device can have its own address, which keeps the internet growing and supports new technologies.

Where is it used?

  • Home routers and smartphones that automatically obtain an IPv6 address from an ISP.
  • Large cloud providers (e.g., Amazon Web Services, Google Cloud) offering IPv6 endpoints for websites and APIs.
  • Internet of Things (IoT) devices such as smart thermostats, security cameras, and industrial sensors.
  • Mobile networks (4G/5G) that allocate IPv6 addresses to phones for faster, more efficient routing.

Good things about it

  • Vast address space - practically unlimited, eliminating the need for NAT tricks.
  • Simpler routing - hierarchical address design makes internet traffic flow more efficiently.
  • Built-in security - mandatory support for IPsec encryption.
  • Better support for mobile - smoother handoffs and auto-configuration for devices on the move.
  • Future-proof - ready for the continued explosion of connected devices.

Not-so-good things

  • Transition complexity - moving from IPv4 to IPv6 requires dual-stack setups and careful planning.
  • Limited legacy support - many older devices, software, and firewalls still only understand IPv4.
  • Learning curve - network engineers must become comfortable with hexadecimal notation and new configuration tools.
  • Potential misconfiguration - incorrect IPv6 settings can expose networks to security risks if not managed properly.