| Feature | IPv4 | IPv6 |
|---|---|---|
| Address space | 4.3 billion | 340 undecillion |
| Address notation | 192.168.1.1 | 2001:db8::1 |
| NAT | Required | Not needed |
| Auto-configuration | DHCP only | SLAAC + DHCPv6 |
| Security | Optional (IPSec) | Built-in (IPSec) |
| Broadcast | Yes | No (multicast) |
| Header complexity | Variable | Fixed (simpler) |
| DNS record | A | AAAA |
Despite IPv4 exhaustion, the transition to IPv6 has been gradual. NAT (Network Address Translation) allowed many devices to share a single IPv4 address, delaying the urgency. Additionally, IPv6 requires updates to routers, ISP infrastructure and software. However, major ISPs and tech companies are now actively rolling out IPv6 – Germany has one of the highest IPv6 adoption rates in the world at over 60%.
IPv4 has been the backbone of the internet since 1981 but its 4.3 billion addresses ran out in 2011. IPv6, with its 128-bit addresses and virtually unlimited address space, is the solution. Beyond address space, IPv6 offers built-in security, simplified headers and automatic address configuration. The transition is ongoing – most modern devices and networks support both protocols simultaneously (dual-stack).