What is IPv6? Explanation of the Internet Protocol | IPv6 Speedtest
What is IPv6?
IPv6 stands for Internet Protocol version 6 and is the successor to IPv4. It is the communication protocol that ensures every device on the internet receives a unique address, so that data packets reach the correct destination. Without IP addresses, the internet simply would not function.
Why was a new protocol needed?
IPv4 uses 32-bit addresses, providing a maximum of around 4.3 billion unique addresses. That seemed more than enough in 1981, but with the explosive growth of the internet – smartphones, tablets, IoT devices, smart TVs – these addresses are almost entirely exhausted. The last major block of IPv4 addresses was allocated by IANA in 2011.
IPv6 permanently solves this problem with 128-bit addresses, providing 340 undecillion (3.4 × 1038) unique addresses. That is so many that every grain of sand on Earth could have billions of addresses.
Differences between IPv4 and IPv6
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address length | 32 bits | 128 bits |
| Maximum addresses | ~4.3 billion | ~340 undecillion |
| Example address | 192.168.1.1 | 2001:db8::1 |
| NAT required | Often | Not needed |
| Built-in security (IPsec) | Optional | Natively supported |
| Auto-configuration | Limited (DHCP) | SLAAC built in |
| Header complexity | Variable (options) | Fixed header, more efficient |
What does an IPv6 address look like?
An IPv6 address consists of eight groups of four hexadecimal characters, separated by colons:
2001:0db8:85a3:0000:0000:8a2e:0370:7334
Consecutive groups of only zeros may be shortened with :::
2001:db8:85a3::8a2e:370:7334
The loopback address (equivalent to 127.0.0.1 in IPv4) is simply ::1.
Advantages of IPv6
- Unlimited address space – no more shortage of IP addresses.
- Better performance – simplified headers make routing more efficient; no NAT overhead.
- Improved security – IPsec is a standard part of IPv6.
- Direct end-to-end connections – every device has a public address; NAT is unnecessary.
- Auto-configuration (SLAAC) – devices can configure themselves without a DHCP server.
- Multicast instead of broadcast – more efficient use of network capacity.
IPv6 adoption in Europe
Several European countries are leading the way in IPv6 adoption. Major internet providers across Europe now deliver dual-stack connections as standard, giving customers both an IPv4 and an IPv6 address.
According to Google statistics, more than 45% of internet users in leading European countries access Google via IPv6. The European Union actively encourages IPv6 deployment through its EU IPv6 Action Plan, aiming to make government services, schools and businesses future-proof.
Dual-stack: the transition in practice
Because not all systems can switch at once, most networks currently use a dual-stack approach: devices have both an IPv4 and an IPv6 address. Connections are preferably established over IPv6; if that fails, the system falls back to IPv4. For the user, this transition is completely transparent.
Check whether you already have IPv6
Want to know if your connection already supports IPv6? Use our IPv6 check or run the speed test directly – it will automatically indicate which protocol your connection is using.