under the hood
why IPv6 is a bigger deal than you think
The internet was built on 32-bit IPv4 addresses. We ran out. Here's what changed — and why this site counts /64 prefixes instead of raw addresses.
IPv4 — one door, many rooms
public IP
your device (private)
Your router does Network Address Translation (NAT) — one public IP shared by every device in your home. Your device's real address never leaves the building. The outside world only sees your router.
IPv6 — no translation needed
your network prefix (/64)
device
No middleman. Your device gets a real, globally routable address. What your machine sees is what the world sees — same address all the way through.
why we count /64 prefixes, not full addresses
Every time an IPv6 device reconnects, it can generate a brand new address within the same /64 network. Counting raw addresses would let one person inflate the counter just by unplugging and replugging their cable.
2601:db8:1a2b:cd4e::a3f2:11b0:cc7d:0001connect
2601:db8:1a2b:cd4e::f891:22a1:44bc:0009reconnect
2601:db8:1a2b:cd4e::1c40:8833:d20e:0017reconnect
3
raw addresses seen
misleading
→
1
/64 networks seen
accurate