IPv6 isn't a future replacement for IPv4 that hasn't arrived yet — for most internet users today, both are already running at the same time, side by side, on the same connection. That overlap, not a clean handoff from one to the other, is what actually matters for day-to-day use.

Why both exist at once

IPv4 addresses are a finite, relatively small pool, and the internet ran out of easy new allocations years ago — which is part of why techniques like NAT (sharing one public IPv4 address across many devices) became standard. IPv6 was designed with a vastly larger address space specifically to remove that scarcity. But because so much existing infrastructure was built around IPv4, the transition has been gradual rather than a cutover: most networks now run "dual-stack," offering both protocols simultaneously rather than replacing one with the other.

What's genuinely different day to day

  • Address format. IPv4 looks like 192.0.2.1; IPv6 looks like 2001:db8::1 — longer, hexadecimal, and usually abbreviated with double colons for consecutive zero groups.
  • NAT is less necessary. With enough address space for every device to have its own public IPv6 address, the address-sharing NAT relies on becomes less relevant on IPv6 networks.
  • Neighbor discovery replaces some IPv4 mechanisms like ARP, changing how devices find each other on a local network — mostly invisible to the end user, but relevant if you're troubleshooting connectivity.

Where this actually bites people

The practical impact for most users isn't the protocol itself — it's that privacy tools built primarily around IPv4 can leave IPv6 unprotected. A VPN that fully tunnels IPv4 while leaving a device's native IPv6 address untouched creates exactly this situation: traffic that prefers IPv6 (which many operating systems do, when it's available) can bypass the VPN entirely without any obvious symptom, since the IPv4 side still looks completely protected. See IPv6 Leaks Explained for the full mechanism.

Checking your own setup

Because a normal IP check only shows whichever protocol your browser used for that one request, verifying consistency requires forcing both protocols to answer independently and comparing them. NetRiskScan's IPv6 Leak Test does exactly this — see How to Run an IPv6 Leak Test.

FAQ

Should I just disable IPv6 to be safe?

It's a reasonable stopgap if your VPN doesn't handle IPv6 correctly, but it's a workaround rather than a fix — check for a native IPv6 setting in your VPN client first.

Does IPv6 make me easier to track?

Not inherently — most systems today use temporary, rotating IPv6 privacy addresses for outgoing connections specifically to limit long-term tracking by address alone, though the underlying network prefix can still be relatively stable.

Will IPv4 eventually stop working?

Not on any near-term timeline — dual-stack coexistence is expected to continue for the foreseeable future rather than a hard cutover.