Every connected device needs an address to talk to the rest of the network. For decades, IPv4 handled that job. The problem is that those addresses have run out. That is why understanding what is IPv6 has become essential for anyone who manages networks, hosts websites or builds applications.
In this article, we explain the protocol in plain terms, compare it with IPv4 and outline the first steps of a migration.
What is IPv6
IPv6 is the sixth version of the Internet Protocol, the standard that defines how data packets are addressed and routed across the internet. The IETF published it in 1998 precisely to solve the IPv4 address shortage.
While an IPv4 address has 32 bits, such as 192.168.0.1, an IPv6 address has 128 bits and is written in hexadecimal, such as 2001:db8:85a3::8a2e:370:7334. On paper, the difference looks small. In practice, however, it changes everything.
Why IPv4 addresses ran out
IPv4 provides roughly 4.3 billion addresses. That number seemed huge in the 1980s. Today, however, nearly every home is full of connected phones, laptops, cameras, sensors and appliances.
Regional registries such as ARIN, RIPE and LACNIC have exhausted their IPv4 pools. As a result, internet providers adopted CGNAT, which places many customers behind a single public IP. It works, but it complicates online gaming, security cameras, VPNs and the identification of users in investigations.
Key differences between IPv4 and IPv6
- Address space: IPv6 offers about 340 undecillion addresses, enough for every device imaginable.
- No mandatory NAT: each device can have its own public address, which simplifies end-to-end communication.
- Automatic configuration: with SLAAC, devices generate their own address without relying on a DHCP server.
- Simpler header: routing becomes more efficient because routers process fewer fields.
- Built-in security support: IPsec is part of the specification, although its use remains optional.
IPv6 benefits in practice
First, direct connections reduce latency in video calls, games and real-time applications. Furthermore, major platforms such as Google, Facebook and Netflix already deliver content over IPv6. According to Google, more than 40% of worldwide traffic to its services now arrives over IPv6.
For businesses, there is another gain: buying IPv4 blocks on the secondary market has become expensive. Therefore, companies that adopt IPv6 early cut infrastructure costs in the medium term.
How to prepare your network and website for IPv6
- Check your provider: confirm that your internet link and your hosting offer IPv6.
- Update equipment: older routers, firewalls and switches may not support the protocol correctly.
- Enable dual stack: running IPv4 and IPv6 side by side is the safest way to migrate.
- Publish an AAAA record: in your domain's DNS, the AAAA record points to the server's IPv6 address.
- Review the firewall: rules written only for IPv4 do not protect IPv6 traffic. Next, replicate your policies.
- Test the application: check logs, blocklists and database columns that store IPs, because an IPv6 address does not fit in a 15-character field.
Frequently asked questions
How do I know if I already use IPv6?
Visit a test site such as test-ipv6.com. It shows whether your provider, router and browser are already connecting over IPv6.
Will IPv4 stop working?
Not in the short term. Both protocols will coexist for many years. Still, new services tend to prioritize IPv6.
Is IPv6 more secure than IPv4?
It is not automatically more secure. Security depends on firewalls, updates and good practices, exactly as with IPv4.
Conclusion
Knowing what IPv6 is is no longer a technical curiosity. The protocol solves the address shortage, simplifies communication and already carries a large share of internet traffic. Start with dual stack, publish your AAAA record and review your firewall. That way, your company is ready for the next phase of the network.