IPv4 vs. IPv6: What’s the Difference?

“You may not have heard it, but the internet has no more space. Yeah, you read it right!”

According to Independent’s article, it stated that many devices are using the internet and the IPv4 protocol has run out of space.

Another source mentioned a similar story where The American Registry for Internet Numbers announced that its free IPv4 addresses are no longer available!

But what does IPv4 got to do with how the internet works?

IPv4 was formed in 1983.

This was before the internet went global. It was created to route internet traffic devices, which is still being used until today.

But as IoT devices continue to grow rapidly, more and more connect online daily.

Yet, there is a problem where IPv4 addresses are no longer available. So, how can this issue be resolved?

Well, a new IP was created to replace IPv4. Known as IPv6, it was meant to tackle the ongoing growth of IoT devices.

But the question is IPv6 actually any better than IPv4?

Let’s find out the key differences between these two.

Before we continue down the path, let’s explore more about IP addresses.

What is an IP?

An IP address, also known as Internet Protocol, is a series of letters or numbers assigned to each device to connect with the internet.

It acts as an identifier and locator for communication purposes between devices.

Any devices, such as computers, smartphones, servers, including smart devices, are assigned to one IP address. Without a unique IP address, your device cannot communicate.

Therefore, IPv4 was created as the first internet protocol version. It created numbers to map devices and build a logical way for internet traffic to route from one to another.

What are IPv4 and IPv6?

IPv4 is the current primary protocol that a majority of internet services still use today. It still carries at least 94% of Internet traffic.

This internet protocol launched 32-bit numerical addresses, which are displayed as four decimal numbers.

Here’s an example:

And here’s your actual IP if you need to know.

Theoretically, IPv4 was supposed to support at least 4.3 billion IP addresses.

But it became apparent that IPv4 couldn’t provide enough IPs for the world population.

As the internet went global, the supply was quickly depleted.

To make it worse, back in the day, mega-corporations used billions of IP addresses. Though some weren’t used to this day, they refuse to give them back.

Nevertheless, when IPv4 hits the limit, it might cripple the internet and prevent new devices from going online.

This is where IPv6 comes in.

IPv6 is the Internet Protocol’s latest version, launched by Internet Engineering Task Force (IETF) in 1994.

By 1998, IPv6 became a Draft Standard and approved as an Internet Standard in 2017.

It was meant for more IoT devices that require internet addresses.

It was also aimed to resolve issues linked to IPv4.

As opposed to IPv4’s 32-bit address range, IPv6 uses 128-bit addressing.

This allows for a legitimate target of 340 undecillion IP addresses.

In other words, we don’t have to worry about running out of IPv6 addresses in the foreseeable future.

Also, there will be plenty of addresses for everyone in the world.

In addition to this, IPv6 enhancement beats IPv4’s many shortcomings — chief among them is security.

However, since its creation, IPv6 hasn’t been fully implemented.

Why? We’ll delve into this next.

So why haven’t we switched to IPv6 yet?

The thing about technologies such as the IPv4 protocol is that it cannot be replaced at least for a while.


Well first, IPv6 doesn’t provide support for backward compatibility with IPv4.

In order words, it can’t be used in any devices configurated with IPv4.

For example, if your device or internet service provider is using the IPv6 protocol, but the website you’re trying to access is using IPv4, you won’t be able to access it.

The only way for this to happen is when your device is compatible with one of these two protocols.

While these days most IoT devices support IPv6, it’s still hard to make a seamless transition worldwide.

All internet service providers, systems, and devices need to be upgraded to IPv6.

As a matter of fact, it will be expensive and time-consuming to upgrade all routers, switches, and servers that have long relied solely on IPv4.

Also, companies are required to encrypt internet traffic with IPSec — a common encryption standard, similar to SSL — so no one can read the content of internet traffic.

Not to mention, encryption requires a lot of computing resources, which means it’s going to be expensive.

Be that as it may, we will see a lot of users migrating to IPv6, but it will be very slow and gradual.

At the moment, only 30 countries globally are adopting IPv6:

  1. Belgium
  1. Greece
  1. Germany
  1. Switzerland
  1. India
  1. USA
  1. Luxembourg
  1. Portugal
  1. Estonia
  1. UK
  1. Ecuador
  1. France
  1. Japan
  1. Canada
  1. Peru
  1. Austria
  1. Malaysia
  1. Trinidad and Tobago
  1. Finland
  1. Czech Republic
  1. Hungary
  1. Netherlands
  1. Ireland
  1. Brazil
  1. Norway
  1. Australia
  1. Romania
  1. Zimbabwe
  1. Sweden
  1. Bosnia

What are the differences between IPv4 & IPv6?

As you probably know by now, IPv4 and IPv6 addresses are fixed in binary numbers.

IPv4 numbers in an address are separated by the period punctuation mark(.) while the colon punctuation mark(:) separates iPv6 numbers in the address.

In general, their purpose is the same, but they work differently.

Here’s a table to illustrate how they function differently from one another (ipv4 vs ipv6).

32 bit in length128 bit in length
4.3 billion IP addresses340 undecillion IP addresses
Reused addressesIoT devices have their own unique address
Decimal formatHexadecimal format
Numeric addressAlphanumeric address
Manual configurationAuto-configuration support
12 header fields8 header fields
Length of Header Filed: 20Length of Header Filed: 40
Support SNMP protocolDoesn’t support SNMP protocol
Packet size: 576 bytesPacket size: 1208 bytes
Virtual Length Subnet MaskNo Virtual Length Subnet Mask

The rise of IPv6 not only meets the demand for more IP addresses but also brings new functionality. It not only solves the problems of IPv4 limited addresses but also offers more benefits.

 Let’s take a closer look.

IPv4 vs IPv6 Security (Better & Improved Security)

IPv6 was built to guarantee security, confidentiality, data integrity, and authentication in mind.

The IPv4 Internet Control Message Protocol (ICMP) is susceptible to malware attacks, so most corporate firewalls often block it.

With the IPv6 Internet Control Message Protocol (ICMP) packets, it uses IPSec making the whole process safer.


Thanks to IPSec, IPv6 uses two security headers, which can be utilized separately or together — Encapsulating Security Payload (ESP) and the Authentication Header (AH).

The ESP produces data-origin authentication, connectionless integrity, protection against replay attacks, and limited traffic flow confidentiality, including privacy and confidentially through the payload’s encryption.

The AH offers security and data-origin authentication against replay attacks.

Now, if IPv4 uses IPSec in the network, security wouldn’t be an issue.

Other Benefits of IPv6 Compare to IPv4

Upgraded connectivity

With IPv6, all IoT devices can have their own IP addresses.

In other words, each device can communicate instantly with a website. There is no need for Network Address Translation (NAT), which was created by engineers to solve the lack of IP addresses in the IPv4 protocol.

Seamless & efficient routing

IPv6 has consistent headers compare to IPv4, which had variables in length.

This means the code for routing IPv6 addresses is much simpler and involves minimal hardware processing. As a result, IPv6 will have high-grade service quality and user experience.

No geographical limitations

From the beginning, IPv4 was created to support the users in the US. That created a lot of issues. With the IPv6, it is available for everyone globally.


One of the main differences between IPv4 and IPv6 is how they assign IP addresses.

With IPv6, IoT devices can assign the IP addresses automatically.

This not only makes it easier for IoT devices connected to the same network, but the address is unique to every compatible device.

It also can combine multiple networks without readdressing.

As you can see, IPv6 has more benefits.

So, the question is, “should you use IPv6?

In short, yes!

If your internet service provider offers it and you have a router and device capable of supporting it, it’s a great idea to turn it on.

But do the best VPN providers offer it?

One thing for sure, most of the free VPN doesn’t have it.

Let’s deep dive into it!

What’s the connection between Internet Protocols and VPN providers?

We’re all about VPN reviews here, so of course, we’re going to discuss the link between IPs and VPNs.

Let’s begin by stating that the most significant portion of VPN service providers operates solely on IPv4.

This means, if you submit a request for a website running on IPv6, it will appear on it using an IPv6 DNS server outside the VPN framework.

In other words, your internet traffic will route through your internet service provider instead of the VPN provider.

That beats the purpose of having a VPN in the first place, thus making you vulnerable to IPv6 leaks.

It also means that your internet service provider can monitor your online activities.

If you haven’t noticed yet, many VPN providers disable IPv6 traffic.

This is because many of them haven’t updated their software and servers to accommodate IPV6 new standards.

To avoid such risks, you can use VPN services that support IPv6.

Luckily, some VPN providers have upgraded their systems to support IPv6 traffic.

Few examples are Mullvad, FrootVPN, and Perfect Privacy.

We haven’t had an opportunity to review their VPN services yet, but we will soon.

If you are not sure how your VPN provider handles IPv6 traffic, it is better to test your IPv6 leaks.

It is recommended to use any testing tools such as IPleak.net to check whether you’re leaking IP information. IPleak.net also covers both IPv6 and IPv4 traffic.

If you see your personal or internet service provider’s IP address revealed on IPleak.net, your VPN isn’t protecting your privacy correctly.

This would make you vulnerable to a DNS leak, which exposes your real IP address and location or disrupts the service of the website you are visiting.

Now, other top-rated VPN providers provide some-sought of leak protection.

An example is NordVPN or ExpressVPN that is not only great in unblocking the Netflix VPN ban but who’s very frank about initiating their leak protection programs.

You can trust that they’ll be effective in terms of privacy and security.

What if your VPN doesn’t support IPv6?

It’s entirely all right if your VPN doesn’t support IPv6.

You don’t have to switch VPN providers as well.

All you have to do is block IPv6.

It’s effortless.

Many VPN services offer a manual disable option for IPv6 users.

You can do it at the router level by disabling IPv6 for all your connected devices.

At this time, there’s no simple way to disable IPv6 on an Android or iPhone device, so you’re better off using the router method.

Is IPv6 necessary at the moment?

IPv4 vs IPv6

Not at the moment. And probably not in the near future.

Even though there are more IoT devices that the availability of IPv4 addresses, many devices can share the same address.

Nevertheless, there will be a complete switch transition over to IPv6.

We won’t know until it happens, but many sources have estimated it will be in the next 10 to 20 years.

And if you don’t utilize IPv6 right now, you aren’t really missing out on anything.

Almost no websites are using IPv6, and a lot of services don’t offer IPv6 addresses.

Not to mention, many internet routers don’t even have IPv6 support.

If it’s more reliable than IPv4, why IPv6 is not used by default?

Having said that, IPv6 is still in its infancy years and has a bright future.

But as we’ve observed, there are a few problems with it — first that most VPN providers don’t support it.

If the leak protection is insufficient, you could be leaking your IP address even when you think your privacy is protected.

So, if you find your preferred VPN isn’t offering IPv6 support, don’t worry!

As for now, just make sure to turn IPv6 off from your device’s settings.

IPv6 adoption is increasing as previously mentioned — 30 countries have adopted it.

Very soon, VPN providers will start laying out adoption plans to accommodate IPv6 in their servers.

But which ever internet protocol that favors you, you should start practicing these 7 habits that can protect your online privacy instantly even without the use of a VPN.