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IPv4 or IPv6: Which protocol to choose for a server in 2025? Detailed comparison, advantages and selection tips

Every device connected to the Internet - be it a server, a personal computer or a smartphone - has a unique identifier known as an IP address (Internet Protocol Address). It serves as a kind of "address" on the global network, allowing devices to exchange information and communicate with each other.

There are currently two IP address standards: IPv4 and IPv6. IPv4 is a time-tested protocol that has been in use since the birth of the Internet. However, its address space is limited, and free addresses have almost run out. This is why it is becoming increasingly important to switch to IPv6, a new protocol that offers an almost unlimited number of IP addresses and enhanced security.

But is IPv6 really better than IPv4 for your server today? In this article, we will compare both protocols in detail, review their advantages and disadvantages, and help you make the best decision on which IP protocol to use in 2025.

IPv4 and IPv6: Basic Differences

What is IPv4?

IPv4 (Internet Protocol Version 4) is the most common IP address protocol, dating back to 1981. It uses a 32-bit address structure divided into four blocks of digits (e.g. 192.168.0.1). The IPv4 address space allows for approximately 4.3 billion unique addresses.

However, when IPv4 was created, no one envisioned that the Internet would become so popular and widespread. Today, in the era of IoT, smart devices, and multiple servers, IPv4 addresses are virtually exhausted.

IPv4 features:

  • 32-bit addressing.
  • Limited address space (4.3 billion addresses).
  • Broad compatibility with legacy devices and software.
  • The need to use NAT technologies due to address scarcity.

What is IPv6?

IPv6 (Internet Protocol Version 6) is a new IP address standard designed to address the problems associated with the IPv4 address shortage. It uses a 128-bit address structure consisting of eight blocks written in hexadecimal format (e.g., 2001:0db8:85a3:0000:0000:0000:8a2e:0370:7334).

IPv6 allows you to create a virtually unlimited number of addresses (approximately 3.4×10³⁸), which completely eliminates the problem of their shortage, even with the constant growth in the number of devices.

IPv6 features:

  • 128-bit addressing.
  • Virtually unlimited address space.
  • Built-in IPsec support for improved security.
  • No need to use NAT.
  • Simplified routing and network configuration.

Why is the world moving to IPv6, and what will happen to IPv4?

The transition to IPv6 is primarily due to the shortage of IPv4 addresses. Already now many providers and data centers are forced to use complex NAT technologies and secondary resale of IPv4 addresses, which increases their cost and complicates the configuration of network infrastructure.

IPv6 also offers a number of technical advantages: built-in security, improved routing efficiency, and simpler network configuration.

However, IPv4 will not disappear immediately - both protocols will coexist for a long time. But in the coming years, IPv6 will gradually dominate, especially in cloud services, IoT devices and mobile networks.

Next, we'll take a closer look at the strengths and weaknesses of each protocol so you can figure out which is best for your server in 2025.

Pros and cons of IPv4

IPv4 is currently the most widely used Internet protocol. But despite its widespread use and compatibility, it has serious limitations that are becoming more and more noticeable every year.

Benefits of IPv4

1. Wide compatibility with equipment

IPv4 is supported by almost all existing devices, including older routers, servers, computers, and cell phones. If you want to maximize compatibility, IPv4 is the best option.

2. Easy to set up and operate

IPv4 addresses are short and convenient and are easy to remember and configure manually. There is also a large amount of documentation and instructions on how to configure IPv4 on different platforms and devices.

3. Supported by most ISPs and data centers

IPv4 is still a standard, so almost all ISPs and hosting providers have no problem providing IPv4 addresses. This guarantees quick and easy integration of your server into any infrastructure.

Disadvantages of IPv4

1. Limited address space

IPv4 address space is practically exhausted. This causes difficulties in obtaining additional addresses and makes expansion of the server infrastructure more expensive and time-consuming.

2. Using NAT (Network Address Translation)

Due to address shortages, many companies and ISPs are forced to use NAT. This technology allows multiple devices to share a single public IP address, but creates additional complexity for some applications and can lead to security issues.

3. Rising cost of IPv4 addresses

Due to their scarcity, IPv4 addresses have become an object of speculation on the secondary market. Their cost is constantly increasing, which makes IPv4 a less attractive option, especially when launching large projects that require a large number of addresses.

Thus, IPv4 is still a relevant and widely used protocol, but its future is becoming less promising as IPv6 gains popularity and becomes a necessity for scalable solutions.

Pros and cons of IPv6

IPv6 is slowly becoming the new standard for networking, offering solutions to the limitations of IPv4. However, this protocol also has its pros and cons that should be considered when deciding whether to use it on a server.

Benefits of IPv6

1. Virtually unlimited number of IP addresses

In IPv6, the address space is so large that it is virtually impossible to exhaust it in the coming decades. This eliminates the problem of IP address scarcity and reduces the cost of acquiring IP addresses.

2. High level of security and built-in encryption (IPsec)

IPv6 was originally designed with modern security requirements in mind. IPsec is built in by default, providing strong data encryption and protection against many types of attacks.

3. More efficient routing and no need for NAT

Doing away with NAT simplifies network architecture, improves performance and eliminates application compatibility issues. IPv6 allows each device to have its own unique global IP address, simplifying communication and reducing latency.

4. Optimized work with mobile devices

IPv6 provides better support for mobile devices and services that change networks frequently. The protocol allows devices to maintain a stable connection when moving between different access points without losing speed or dropping sessions.

Disadvantages of IPv6

1. Not all ISPs fully support IPv6

Although IPv6 support is growing, some ISPs still do not offer full integration of the protocol. This may make it difficult or expensive to connect your server via IPv6 in some regions.

2. Difficulties in integrating with legacy IPv4 networks

Migrating from IPv4 to IPv6 requires special preparation and configuration. Because these protocols are not fully interoperable, it is often necessary to use dual-stack or tunneling technologies, which can increase the complexity of the infrastructure.

3. Requires some experience to set up correctly

IPv6 uses longer and more complex addresses, which complicates network configuration and infrastructure management. Successful implementation and operation of IPv6 requires skilled professionals who can properly configure the network and ensure its smooth operation.

IPv6 is the protocol of the future and solves the critical problems of IPv4, but at this stage it requires more technical expertise and additional infrastructure preparation.

How to choose: IPv4 or IPv6?

The choice of IP addressing protocol in 2025 depends directly on your objectives, infrastructure, and long-term goals for your project. Let's look at situations where IPv4 is best and scenarios where IPv6 is preferred.

When should IPv4 be used?

Compatibility with existing customers and equipment

If your project is focused on maximizing compatibility and interoperability with existing devices and clients, IPv4 remains the best choice. Most legacy network devices, ISPs and server solutions still primarily support IPv4.

Minimal setup and support time

IPv4 is a well-known and time-tested protocol that can be configured by most system administrators and IT specialists. For projects with limited deployment time and minimal resources to support the network infrastructure, IPv4 is the best option.

Proven infrastructures and data centers

If you are hosting the server in traditional data centers or ISPs that do not provide full IPv6 support, choosing IPv4 will avoid additional complexities and hardware compatibility issues.

When is it best to migrate to IPv6?

Use of new equipment and modern data centers

If you are building a new infrastructure or upgrading equipment, it makes sense to use IPv6 right away. Modern servers, routers and network equipment are already fully compatible with IPv6, so you can take full advantage of its benefits without limitations.

Long-term planning and scaling of IT infrastructure

When planning for the long-term growth of a project or network, migrating to IPv6 becomes an essential decision. With the inevitable depletion of IPv4 addresses and their rising costs, IPv6 will ensure the resiliency and flexibility of your network for years to come.

Mobile applications, cloud services and IoT projects

Projects related to mobile devices, cloud services and the Internet of Things (IoT) are best developed using IPv6. This protocol provides more efficient routing, stable connectivity during network changes, and support for a huge number of devices.

Therefore, the choice between IPv4 and IPv6 depends on the specific requirements of your project, your current infrastructure and your strategic goals. Ideally, you should consider using Dual Stack, which provides compatibility between the two protocols, allowing for a smooth and seamless transition to IPv6 when needed.

Using IPv4 and IPv6 simultaneously: Dual Stack

Dual Stack technology allows IPv4 and IPv6 to be used simultaneously on the same server or network device. In 2025, it is one of the most popular approaches to ensure a smooth transition from IPv4 to IPv6 without risk or loss of interoperability.

What is Dual Stack technology and why is it convenient?

Dual Stack is a networking approach in which servers and equipment run two versions of the protocol simultaneously: IPv4 and IPv6. This provides maximum flexibility and interoperability, allowing both old and new clients and devices to be served without limitation. The use of this technology is particularly useful in a gradual transition to IPv6, where some audiences and providers are still operating on IPv4.

How does parallel support for IPv4 and IPv6 work?

The essence of Dual Stack is that two address stacks are configured on a server or network device at once. The client device, in its turn, connects using the protocol that is available or convenient for it at the moment:

  • If the client supports IPv6, the connection is established over IPv6.
  • If IPv6 is not available, the device automatically connects using IPv4.

In this way, the network infrastructure ensures full compatibility and users get the most suitable connection for them without additional configuration and switching.

In what cases does it make sense to use Dual Stack?

Dual Stack is the ideal solution in the following scenarios:

  • Gradual Migration to IPv6: Dual Stack is suitable for companies that are gradually adopting IPv6 but do not want to risk compatibility with current clients.
  • International projects: for global Internet resources, the use of both protocols is critical because the level of IPv6 adoption differs from country to country.
  • Hosting providers: companies that provide VPS, cloud solutions and dedicated servers widely use Dual Stack to give customers maximum choice and flexibility.
  • Online services and web platforms: for projects with a large number of users, Dual Stack technology helps to reach all clients regardless of the protocol used.

Thus, using Dual Stack is a robust solution that can effectively manage the transition from IPv4 to IPv6 while avoiding potential interoperability issues and performance losses.

How to switch from IPv4 to IPv6: step-by-step instructions and recommendations

Migrating from IPv4 to IPv6 is a deliberate process, but with proper planning, it becomes a simple task. In 2025, this issue is particularly relevant as the global shortage of IPv4 addresses intensifies and many companies look to secure the future of their network infrastructures.

Step-by-step instructions for migrating from IPv4 to IPv6

Step 1: Verify hardware and software readiness

Before you begin the migration, it is important to make sure that your network hardware and software support IPv6. Check:

  • IPv6 compatibility of routers and switches.
  • IPv6 support by your operating system and software (Linux, Windows Server).
  • Updates all systems and software to the latest version that supports IPv6.

Step 2: Obtain IPv6 address space

To work with IPv6, you need to obtain a block of IPv6 addresses from your ISP or registrar (e.g. RIPE NCC). Contact your ISP and get your IPv6 range assigned to you.

Step 3: Scheduling IPv6 addressing

Create a clear addressing plan that allows you to structure your networks conveniently and logically. IPv6 allows for a much more flexible and scalable address space than IPv4. For example, you can use separate subnets for different services, offices, or regions.

Step 4: Configure IPv6 on the server

Configure IPv6 on your server by assigning dedicated addresses and making sure that the interface settings are correct. Remember:

  • Configure IPv6 routing.
  • Verify that the Neighbor Discovery protocol is working.
  • Write correct AAAA DNS records, which are responsible for IPv6 addresses.

Step 5: Testing the IPv6 connection

After configuring IPv6, perform a thorough test:

  • Check the operation of IPv6 addresses for availability from the Internet.
  • Use utilities such as ping6, traceroute6 to diagnose the network.
  • Ensure that web applications and services work correctly over IPv6.

Step 6: Dual Stack Implementation

If your clients do not yet fully support IPv6, configure IPv4 and IPv6 to run in parallel (Dual Stack). In this way, you will maintain maximum compatibility with all users.

Possible problems when migrating to IPv6 and how to solve them

There can be some challenges when migrating to IPv6:

  • Hardware incompatibility: Check compatibility in advance and purchase devices that support IPv6.
  • DNS configuration errors: Verify correct AAAA records, avoid conflicts with IPv4 records.
  • Routing issues: Configure static and dynamic routes with IPv6 in mind, test them thoroughly before going live.
  • Lack of IPv6 support from your ISP: Make sure your ISP supports IPv6 before migrating.

How do you check if your server is IPv6 ready?

Use special tools and utilities to verify that your server is ready for IPv6:

  • IPv6 testers (test-ipv6.com) - test your site and network in IPv6 mode.
  • The ping6 and traceroute6 utility - diagnose IPv6 connectivity to your nodes.
  • The commands ifconfig or ip addr in Linux and ipconfig /all in Windows - show whether an IPv6 address is assigned to your server.

Careful testing and proper IPv6 configuration will ensure your server has a smooth and seamless transition, as well as a stable network for years to come.

Conclusion

The choice between IPv4 and IPv6 in 2025 depends on the specific objectives of your project, your infrastructure and your company's long-term plans. IPv4 continues to be in demand due to its compatibility and ease of integration, but is gradually losing ground due to limited address space and the high cost of new IP addresses.

IPv6 is clearly the future. It offers an almost infinite number of addresses, improved security, high performance and efficient traffic routing. Therefore, if you are planning infrastructure development for the future and want to ensure the stability and reliability of your servers, it is better to start a smooth transition now.

Assess the current state of your infrastructure: verify that your hardware, software and networking solutions are compatible with IPv6. Utilize Dual Stack technology to easily transition and maintain compatibility with existing customers. By starting the transition to IPv6 today, you will ensure your business has a sustainable and secure future in the digital world.

Test your infrastructure's readiness for IPv6 now and take an important step towards the technology of the future.