The core difference in IPv4 vs IPv6 is simple: IPv6 has a vastly larger address space and a more modern design, but IPv4 and IPv6 will coexist in the real world for a long time. For most users, the difference you actually feel is not “which one is more advanced in theory.” It is whether your network, device, game, app, and VPN handle both protocols correctly.［1］［2］［3］［4］

If you only remember one thing, make it this: IPv6 is newer, has far more addresses, and includes more modern design choices, but IPv4 is still everywhere. The real world is dual-stack coexistence, not instant replacement. For background, read What Is a VPN? A Complete Beginner’s Guide and Types of IP Addresses: Public, Private, Static, Dynamic, IPv4, and IPv6.

Key Takeaways

IPv4 uses 32-bit addresses, while IPv6 uses 128-bit addresses. The first problem IPv6 solves is address exhaustion.［1］［2］［3］

IPv6 is generally considered the more modern protocol, especially for addressing and long-term network design.［2］［3］

Speed and gaming performance do not depend on protocol version alone; carriers, routing, devices, and service support matter too.

IPv6 does not automatically encrypt traffic or make it safer; both stacks need correct security policy.［6］

For VPN users, the practical question is whether the VPN supports IPv6 and prevents IPv6 leaks.

What is IPv4?

IPv4 is the IP protocol version still used at massive scale across today’s internet. RFC 791 defined it in 1981, including the familiar dotted-decimal address format such as 192.168.1.1.［1］

It has worked for decades and supported a huge part of internet history. The problem is that the number of connected devices far exceeded early expectations, so IPv4 address space became tight.［3］

What is IPv6?

IPv6 is the next-generation internet protocol. Defined in RFC 8200, it expands the address length to 128 bits and uses colon-separated hexadecimal groups, such as 2001:db8::1.［2］

Its biggest advantage is the enormous address space, but that is not the only point. IPv6 was also designed to make modern routing, automatic configuration, and long-term scaling easier.［2］［3］

IPv4 vs IPv6 side by side

The shortest useful comparison looks like this:

Dimension	IPv4	IPv6
Address length	32 bits［1］	128 bits［2］
Address count	About 4.29 billion［3］	About `3.4 x 10^38`［3］
Notation	Dotted decimal	Colon-separated hexadecimal
Real-world deployment	Still extremely common	Growing quickly, usually alongside IPv4［4］

Address space

This is the most cited difference and the direct reason IPv6 exists. IPv4 has a limited address pool. IPv6 has enough address space that exhaustion is not a practical concern in the same way.［3］

Notation and readability

IPv6 addresses are longer and look more complex. That is true. Most users rarely need to memorize them, though, because DNS still handles most name resolution for you.

Deployment model

The internet did not move from “IPv4 today” to “IPv6 tomorrow.” Many carriers, websites, and devices use dual stack, meaning both protocols run in parallel.［4］

For a VPS, address assignment, reachability, and VPN coverage are separate checks. First confirm that the provider assigned IPv6 to the instance and that the guest has the documented address and default route; a visible address alone does not establish a working upstream path. Provider-specific setup differs, so follow that provider’s current instructions rather than copying another host’s prefix or gateway.［7］

Next distinguish the cloud firewall from the host firewall and check whether the intended service actually listens on IPv6. A service listening only on IPv4 does not become reachable over IPv6 when an address is added. The return route must also work. IP forwarding belongs to a host routing traffic for other systems; it is not a prerequisite for every local service and should not be enabled as a generic repair. Linux documents IPv6 forwarding and router-advertisement behavior separately.［6］［8］

Finally verify the intended service port and authorized application request, not just ping. An ICMPv6 response does not prove that a TCP or UDP listener is reachable or that service authentication succeeded; a blocked echo request alone does not establish that the service is down. These server-side observations also do not prove that a VPN client captures IPv6 traffic. Keep the server path, authentication, and client coverage as separate evidence.［6］

On a server you control, adding an IPv6 outbound path to a self-hosted proxy shows how to confirm which address family a destination actually sees.

Is IPv6 faster than IPv4?

Many people ask: is IPv6 faster? The accurate answer is: sometimes, but not guaranteed.

On some networks, IPv6 routing may be more direct or involve shorter paths, so it can feel faster. But speed still depends on carrier routes, DNS, CDNs, device implementations, and the target service itself.

So “IPv6 is always faster” is too absolute. A better version is: IPv6 can be faster, but protocol version alone never determines speed.

Is IPv6 more secure than IPv4?

IPv6 does not automatically encrypt traffic or make a network safer. IPsec is a separate security mechanism; referring to it in a protocol specification does not prove that a particular connection uses it. IPv4 and IPv6 deployments both need appropriate access controls, updates, and firewall policy.［6］

If you mean real-world safety, the answer is more complicated. Security still depends on:

whether firewall rules cover both stacks;
whether devices and routers are configured correctly;
whether dual-stack networks leave unprotected paths open.［6］

The practical security question is whether both stacks enforce the intended policy, not which version is newer.［6］

Is IPv4 or IPv6 better for gaming?

Gamers often care about this because latency and stability matter more than theory.

The practical answer is still: it depends on routing, the carrier, and the game service, not just the protocol version.

If a game server, platform, or ISP supports IPv6 well, the experience may be smoother. If support is incomplete, compatibility problems can appear. For gaming, the key questions are:

Does the game service support the protocol well?
Is your home network and ISP stable?
Are dual-stack or NAT behaviors causing connection issues?

This connects to How to Change NAT Type on PC: Causes and Fixes, because many players are really trying to improve connectivity and matchmaking.

Will IPv6 replace IPv4?

IPv6 adoption will keep growing in the long run, but in the short and medium term, coexistence is more realistic than sudden replacement. Google and APNIC statistics both show IPv6 adoption rising while IPv4 remains widely present.［4］［5］

The realistic answer is: IPv6 will become more important, but IPv4 will not disappear overnight.

Why should VPN users care about IPv4 and IPv6?

If a VPN protects IPv4 but does not handle IPv6 traffic, you may get an IPv6 leak. That means the VPN appears to be on, but some requests may still bypass the tunnel and connect directly.

That is why you should not judge a VPN only by whether your IPv4 address changed. You should also check IPv6, DNS, and other leak boundaries. For more context, read What Does a VPN Hide? What It Can and Cannot Protect and Does a VPN Make You Anonymous? Not Fully, but It Reduces Exposure.

To run that check with AethoVPN, open an IPv6-capable leak test with the connection off and note the IPv6 address it reports, then connect to a location from the in-app list and repeat the same test. If the second run still shows your own IPv6 address, that traffic is bypassing the tunnel. AethoVPN's public pages do not describe its IPv6 handling, so the difference between the two runs is the evidence, not an assumption either way. Save a screenshot of the disconnected result first, then start the 3-day free trial and take the connected screenshot from the same test page so the two addresses sit side by side.

On an OpenWrt router, a changed IPv6 prefix from your provider can break routes or firewall boundaries; the prefix delegation guide covers checking both after the prefix changes.

Summary

The first major difference in IPv4 vs IPv6 is address size: IPv4 is 32-bit, while IPv6 is 128-bit.［1］［2］［3］
IPv6 is generally more modern and better suited for long-term internet scaling.［2］［3］
Speed, gaming performance, and reliability do not depend only on protocol version; carriers, devices, and service support matter too.
IPv6 does not automatically encrypt traffic or make it safer; both stacks need correct security policy.［6］
For VPN users, the practical goal is not choosing a side. It is making sure both stacks are handled correctly.

FAQ

What is the biggest difference between IPv4 and IPv6?

Address length and address count. IPv4 uses 32-bit addresses, while IPv6 uses 128-bit addresses and has a much larger address space.［1］［2］［3］

Is IPv6 always faster than IPv4?

No. It may be faster on some networks, but speed still depends on routes, DNS, CDNs, carrier networks, and target service support.

Is IPv6 more secure than IPv4 in practice?

Not automatically. A network is as safe as the firewall rules, updates and access controls applied to each stack; an IPv6 path left open while IPv4 is filtered is a common gap.［6］

Will IPv6 completely replace IPv4?

IPv6 will keep growing, but coexistence is more realistic in the short and medium term than a single complete cutover.［4］［5］

Should I use IPv4 or IPv6 for gaming?

There is no universal answer. Look at your ISP route, the game server’s support, and your local network conditions rather than the protocol name alone.

Why does a VPN need IPv6 support?

If a VPN protects only IPv4 and ignores IPv6, some traffic may bypass the tunnel and create an IPv6 leak.

How do I know whether I am using IPv4 or IPv6?

Many users are using both. Your device, ISP, and the website you visit collectively decide which protocol a connection uses, often automatically in a dual-stack setup.

Disclaimer: This article is for general networking and security education only. It is not network architecture, compliance, or legal advice. Enterprise networks, cloud environments, campus networks, and ISP networks may require different IPv4/IPv6 deployment, compatibility, and security policies.

Sources:

RFC 791 - Internet Protocol — https://www.rfc-editor.org/rfc/rfc791.html
RFC 8200 - Internet Protocol, Version 6 (IPv6) Specification — https://www.rfc-editor.org/rfc/rfc8200
ARIN - IPv4 and IPv6 — https://www.nro.net/wp-content/uploads/2011/02/ipv4_ipv6.pdf
Google - IPv6 Statistics — https://www.google.com/intl/en/ipv6/statistics.html
APNIC Labs - IPv6 Measurement Maps — https://stats.labs.apnic.net/ipv6
RFC 9099 - Operational Security Considerations for IPv6 Networks — https://www.rfc-editor.org/rfc/rfc9099.html
DigitalOcean - How to Enable IPv6 on Droplets — https://docs.digitalocean.com/products/networking/ipv6/how-to/enable/
Linux Kernel - IP Sysctl — https://www.kernel.org/doc/html/latest/networking/ip-sysctl.html

Sources checked 9 October 2026.

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IPv4 vs IPv6: Addressing, Performance, and Privacy