What IPv6 is
IPv6 (Internet Protocol version 6) is the successor to IPv4. It uses 128-bit addresses, written as eight groups of four hexadecimal digits separated by colons, for example 2001:0db8:85a3:0000:0000:8a2e:0370:7334. Leading zeros and long runs of zeros can be shortened, so that address may appear as 2001:db8:85a3::8a2e:370:7334.
Why it matters
IPv4 ran out of free addresses, and IPv6 solves that by offering about 340 undecillion possible addresses. That is enough to give every device its own public address without relying on workarounds. IPv6 also simplifies routing, improves auto-configuration, and was designed with security extensions built in from the start.
Adoption and coexistence
Most networks now run both protocols side by side, a setup called dual stack. A modern home connection often receives an entire IPv6 prefix rather than a single address:
- A
/64block is the standard size for a single network segment. - Devices can generate their own addresses within that block.
For example, a phone on a mobile network may hold an IPv6 address while still reaching older IPv4-only sites through translation. You can view your own IPv6 address with the WhatIP my-ip tool when your connection supports it.