IPv6 vs IPv4: A Deep Dive into the Core Differences and Benefits, Plus a Step-by-Step Guide to Enabling IPv6 on Every Platform

IPv6 vs IPv4: A Deep Dive into the Core Differences and Benefits, Plus a Step-by-Step Guide to Enabling IPv6 on Every Platform (2025 Edition)

1. Why upgrade? The core differences between IPv4 and IPv6

The internet's "house numbers" (IP addresses) are running out — a story everyone has heard by now. But beyond sheer quantity, where exactly does IPv6 beat IPv4? And what does that mean in practice for an ordinary user?

1. A dimensional leap in address space

If IPv4's address count is like the parking spaces in a housing estate (about 4.3 billion, long since exhausted), then IPv6's address count is like every grain of sand on Earth (2 to the power of 128).

• IPv4: 32-bit addresses, for example 192.168.1.1, and you have to fight for a public IP.
• IPv6: 128-bit addresses, for example 240e:xxxx:..., theoretically enough to give every speck of dust in your home its own public IP.

2. Goodbye NAT — a blessing for gaming and P2P downloads

This is IPv6's biggest advantage for ordinary users. In the IPv4 era, because public IPs were scarce, carriers usually handed you a private address, and you had to pass through layer upon layer of NAT (Network Address Translation) to reach the internet. It is like not being able to address a letter directly — you have to send it to the front desk and let them pass it on for you.

IPv6's advantage is this:

Decentralised direct connections: every device has a public IP, so computers, phones, and NAS units can talk straight to internet endpoints. When gaming (on a Switch or Xbox, say), you are no longer confined by strict NAT3/NAT4 restrictions, and P2P downloads (BitTorrent) can connect to other peers far more easily — with speeds to match.

3. Higher data-transfer efficiency and better security

IPv6 is not simply "IPv4 with longer addresses". Its header design is more streamlined, so routers process it faster. At the same time, security (IPSec) was considered from the outset, which compared with IPv4 means wrapping your network data in a sturdier suit of armour.

2. Hands-on: how do you enable IPv6? (Works on every device)

Most ONTs and routers today ship with IPv6 disabled, which is why many people cannot use it even when their broadband supports it. Below is a detailed configuration guide for Windows, Mac, Linux, and routers.

Last updated: 26 October 2025

👉 Step one: configure the router (TP-LINK as the example)

The router configuration is the core of it, and there are usually two situations:

Case A: the ONT is bridged and the router dials

If your router handles the dial-up connection, follow these steps:

1. Log into the router's admin panel.
2. Find "IPv6 settings" and turn the feature on.
3. WAN connection type: choose "Broadband dial-up".
4. The key point: tick "Reuse the IPv4 dial-up link" (this avoids a second authentication failure).

Case B: the ONT dials and the router obtains an IP automatically

If your router works as soon as you plug it in (the ONT handles dial-up), set it to "Bridge mode" instead:

1. Go to "IPv6 settings".
2. WAN connection type: choose "Bridge mode" (Passthrough).
3. Save the settings; the router will pass the IPv6 address assigned by the ONT through to the devices below it.

👉 Step two: configure the computer (Windows 10/11)

With the router working, you still need to make sure your computer's operating system has the IPv6 stack enabled.

1. Open Control Panel > Network and Sharing Center.
2. Click "Change adapter settings" on the left.
3. Right-click the network adapter you are using (Ethernet or Wi-Fi) and choose "Properties".
4. In the list, find "Internet Protocol Version 6 (TCP/IPv6)" and make sure its checkbox is ticked.
5. Double-click to open it, and choose "Obtain automatically" for both address and DNS.

👉 Step three: advanced configuration for Mac and Linux

For macOS users:

Go to "System Preferences" -> "Network" -> select the current network -> "Advanced" -> "TCP/IP". Set the IPv6 configuration mode to "Automatically" and you are done.

For Linux users (Ubuntu/CentOS):

Linux servers usually need the configuration file edited by hand. Taking netplan as the example, make sure dhcp6: true is enabled.

# Temporary test command
sudo ip -6 addr add 2001:db8::1234/64 dev eth0

# Check the status
ip -6 addr show

3. Final verification: is IPv6 actually working?

Once the configuration is done, how do you confirm you have successfully joined the IPv6 internet? The simplest way is to use an online test tool.

If you are technically minded, you can also test from the command line:

• Windows: open CMD and enter ping -6 www.baidu.com
• Mac/Linux: open a terminal and enter ping6 www.baidu.com

If you see a reply from an address like 240e:..., congratulations — your network has just taken a qualitative leap forward!

Advanced tip: how do you change Windows' IPv4/IPv6 priority?

Many people find that after enabling IPv6, web browsing actually gets slower, or some applications become unstable. This is usually because Windows prefers IPv6 by default, while your IPv6 route is not as good as your IPv4 one.

In fact, you do not need to turn IPv6 off! You only need to adjust the system priority so that your computer "uses IPv4 for everyday browsing and keeps IPv6 as a fallback".

1. Test the current priority

First, we need to confirm which protocol your computer currently prefers.

Open CMD (Command Prompt) and enter the following command to test a dual-stack domain:

ping ip.17nas.com

Reading the result:
1. If it returns a long address like 240e:... then IPv6 takes priority.
2. If it returns a short address like 106.xx.xx.xx then IPv4 takes priority.

2. Inspect the system prefix policy

Run CMD as administrator and enter the following command to view the priority table:

netsh interface ipv6 show prefixpolicies

By default, Windows' policy is as follows (a higher number means higher priority):

• 50 ::1/128 (loopback)
• 40 ::/0 (the IPv6 default address, priority 40)
• 35 ::ffff:0:0/96 (the IPv4 address, priority 35)

As you can see, 40 > 35, so the system uses IPv6 first by default.

3. One command: make IPv4 take priority

If you want to keep IPv6 available (for remote access) but prefer the more stable IPv4 for everyday browsing, run the following command in anadministrator CMD:

netsh interface ipv6 set prefixpolicy ::ffff:0:0/96 100 4

How it works: this command raises the priority of IPv4 (::ffff:0:0/96) to 100, far above IPv6's 40. It takes effect immediately, with no reboot needed.

Verify again:

ping ip.17nas.com
# It should now return an IPv4 address

4. How do you restore the defaults?

If your network improves later and you want IPv6 priority back, or the settings get tangled, use the reset command (a reboot is required):

netsh interface ipv6 reset
shutdown -r -t 0

# 1. Force a lookup of this machine's public IPv4 address
curl v4.17nas.com

# 2. Force a lookup of this machine's public IPv6 address
curl v6.17nas.com

# 3. Smart priority detection (whichever IP comes back is the one the system prefers)
curl ip.17nas.com

Related reading: IPv6 reachability monitoring report by province · Complete guide to direct IPv6 access to your NAS