IPv4 vs IPv6
For decades, IPv4 has structured the majority of global internet traffic. However, in the face of the explosion of connected devices, the transition to IPv6 is becoming essential. Discover the differences between these two IP protocols, their roles, and why evolution is crucial for modern networks.
What is the difference between IPv4 and IPv6?
A matter of format and addressing capacity
The IPv4 protocol relies on a 32-bit addressing system, allowing for the generation of approximately 4.3 billion unique addresses. While this seemed sufficient when it was introduced in the 1980s, the proliferation of connected devices (computers, smartphones, IoT objects) quickly showed its limits.
IPv6, designed to address this saturation, uses a 128-bit format. As a result, it offers an almost infinite addressing space, with 340 sextillion addresses available. This allows each device, each service, and even each object to have a unique IP address in the world, without resorting to NAT (Network Address Translation).
Beyond the number of addresses, these two versions also differ in their configuration mode, their data packet management, and their approach to security and network performance.
Comparison table: IPv4 vs IPv6
Features | IPv4 | IPv6 |
Address length | 32 bits | 128 bits |
Number of addresses | ≈ 4.3 billion | ≈ 340 sextillion |
Notation | Decimal, e.g. 192.168.0.1 | Hexadecimal, e.g. 2001:0db8:85a3::8a2e:0370:7334 |
Configuration | Manual or via DHCP | Auto-configuration (stateless) |
Native security | Optional | Integrated (IPsec) |
NAT compatibility | Necessary | Unnecessary due to extended addressing |
Performance | Less optimal in case of NAT | More efficient routing, reduced latency |
VPN support | Yes, but more complex | Yes, with enhanced security options |
| Current deployment | Majority, but declining | Growing, especially in modern services |
Protocols: understanding their role in the Internet
What is an Internet Protocol (IP)?
In a computer network, a protocol is a set of rules that govern the transmission of data between devices. The IP protocol (Internet Protocol) plays a central role in the functioning of the Web: it allows each connected machine to be identified by a unique address and to communicate with others, regardless of their location in the world.
Every time you access a web page, use an online service, or launch a VPN, data packets are sent across the network. The IP protocol breaks down this data, routes it to its destination, and then reassembles it at the destination, ensuring that both the sender and receiver are properly identified.
The IP protocol thus acts as the distribution system of the Internet, organising the flows of data, connection, and communication between all connected devices.
Why are there multiple versions of the protocol?
The IP protocol was designed in a context where the number of possible connections seemed limited. IPv4, the first widely adopted version, proved to be very effective in its early days. But with the rise of the Internet, the explosion of users, the multiplication of services, VPNs, smartphones, connected objects, and autonomous machines, the address space of IPv4 has become insufficient.
This is why IPv6, a new version of the protocol, was developed: it adapts to modern needs in terms of performance, privacy, data security, and large-scale connectivity.
The existence of multiple versions is thus explained by technological evolution and the limits reached by the initial protocols. Today, both coexist, even though IPv6 is primarily designed to take over sustainably.
Why move from IPv4 to IPv6?
The technical limitations of IPv4.
As mentioned earlier, IPv4 has supported the development of the Internet for several decades. However, it now shows several major limitations that hinder the growth of modern networks:
- Saturation of the address space: with only 4.3 billion available addresses, IPv4 can no longer meet the needs of a world with several billion connected devices.
- NAT (Network Address Translation): to address this shortage, techniques like NAT have been implemented, allowing multiple machines to share the same public address. But this complicates network configuration, limits certain direct connections (e.g., P2P, VoIP), and can impair performance.
- Limited security and privacy: IPv4 does not natively offer encryption or data authentication, making communications vulnerable without additional security layers (like a VPN or IPSec).
- Increasing complexity for network administrators: the scarcity of addresses leads to increasingly specific configurations, making the system less scalable in the long term.
The advantages of IPv6
IPv6 was designed to directly address these limitations, with built-in features that facilitate network management while improving performance and security:
- Massive addressing: with its 128 bits, IPv6 offers an almost unlimited number of addresses. Each device can thus have a unique address, eliminating the need for NAT.
- Automatic configuration: IPv6 supports stateless autoconfiguration, allowing devices to automatically configure themselves without human intervention, simplifying network administration.
- Native security: features like IPsec are integrated into the architecture of IPv6, providing a better level of privacy, integrity, and data authentication.
- Improved network performance: without NAT, packets travel faster and latencies are reduced. Routing is also optimized thanks to a more hierarchical address structure.
- Support for new uses: IoT, real-time web applications, modern VPNs, cloud computing… all use cases that fully benefit from the capabilities of IPv6.
What are the impacts for users and businesses?
Compatibility of systems and devices
The transition to IPv6 is not just about network infrastructure, as it also impacts end users, businesses, and all connected devices.
The good news: the majority of modern operating systems support IPv6 natively, including:
- Windows, macOS, Linux;
- Android and iOS
- most internet boxes, routers, and recent network equipment.
On the other hand, some older hardware or software may require an update or specific configuration. For businesses, it is crucial to ensure that their entire digital ecosystem (services, online applications, VPNs, cloud solutions, and even the purchase of a domain name) is IPv6 compatible, to guarantee accessibility and optimal performance in the long term.
Performance, security, and connection quality
IPv6 brings concrete benefits in terms of network performance:
- reduced latency thanks to more direct routing;
- more stable connection between devices, without an intermediate gateway (NAT);
- faster data transmission in certain situations.
In terms of security, IPv6 addresses are often random and temporary, making them harder for attackers to exploit. Combined with native encryption (IPsec), this architecture enhances user privacy and strengthens the security of web exchanges.
IPv6 around the world: adoption and availability
The adoption of IPv6 is steadily progressing worldwide. Many countries, such as France, Germany, and India, already exceed 70% IPv6 traffic. Internet service providers (ISPs), major cloud players, streaming services, and social networks have massively adopted this protocol.
At OVHcloud, all our cloud services, web hosting and dedicated servers are fully IPv6 compatible and designed to support this technological transition while ensuring performance and global connectivity.
Ignoring the transition could lead to accessibility issues or even performance limitations in the coming years. It is therefore crucial to check now the compatibility of your system, applications, and network infrastructure.
Your questions answered
Is IPv6 compatible with all Internet service providers (ISPs)?
No, not all ISPs yet offer full support for IPv6. Some enable it automatically, while others require an explicit request from the user. It is also possible that your hardware is ready, but your provider still blocks access to certain IPv6 ranges. Before initiating a transition, it is recommended to consult your ISP's documentation or contact them directly. You can also perform a simple test to check your IPv6 connectivity using free online tools. Adoption also depends on the region you are in.
Does IPv6 improve protection against network attacks?
IPv6, unlike IPv4, is not a miracle solution against network attacks, but it offers integrated security mechanisms like IPsec, which enhances authentication, data encryption, and integrity. It also incorporates temporary and random addresses, which complicate the tracking of devices and limit the risks of misuse identification. However, these options are not always enabled by default, and good network security always relies on a comprehensive strategy: firewalls, updates, network traffic monitoring, use of VPNs, etc. Therefore, IPv6 should be seen as an additional secure layer, not as an absolute barrier on its own.
Is it possible to use IPv4 and IPv6 in parallel?
Yes, and this is even the case for the majority of current networks. We talk about dual stack, meaning that systems support both protocols in parallel. This ensures maximum compatibility with services still on IPv4 while benefiting from the advantages of IPv6 when available. Coexistence is therefore not only possible but highly recommended to avoid any service interruption or access issues, especially for businesses managing multiple environments.
What types of applications or services benefit the most from IPv6?
Services that require direct and fast connections particularly benefit from IPv6. This is the case for online gaming, video conferencing solutions, VoIP services, or even connected objects (IoT). Even more traditional projects, such as creating a website, benefit from IPv6 to ensure uninterrupted accessibility, regardless of the protocol used by visitors. IPv6 allows these devices to connect without going through mechanisms like NAT, thus reducing latency and routing errors. Moreover, for cloud services, IPv6 facilitates scalability and interoperability, especially in modern architectures like microservices.
Should technical teams be trained to manage IPv6?
Yes, to a certain extent. Although IPv6 aims to simplify network configuration, its addressing logic, integrated security mechanisms, and packet management differ significantly from IPv4. A short training on the basics, diagnostic tools, and best deployment practices can prevent many errors. Furthermore, for DevOps teams or system administrators, a good understanding of IPv6 is essential to ensure optimal network performance and effective service management.