IPv4 vs IPv6
Direkter Vergleich der beiden Internet-Protokollversionen — wie sie sich in Adressierung, Routing, Sicherheit und realer Akzeptanz unterscheiden.
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address size | 32-bit (4 bytes) | 128-bit (16 bytes) |
| Total addresses | 4.29 billion (2³²) | 340 undecillion (2¹²⁸) |
| Format | 192.0.2.42 (dotted decimal) |
2001:db8::8a2e:370:7334 (colon hex) |
| Header size | 20–60 bytes (variable) | 40 bytes (fixed) |
| Fragmentation | Routers and sender | Sender only (Path MTU Discovery) |
| NAT required? | Yes — common due to exhaustion | No — every device gets a global address |
| IPsec | Optional add-on | Built-in (mandatory support) |
| Broadcast | Yes (e.g. 255.255.255.255) | No — uses multicast instead |
| Checksum | Header checksum field | Removed (handled by lower layers) |
| Configuration | DHCP or manual | SLAAC (stateless auto-config) + DHCPv6 |
| DNS record | A record |
AAAA record |
| Reverse DNS zone | .in-addr.arpa |
.ip6.arpa |
| IANA exhaustion | Feb 2011 (top-level free pool) | Not expected for centuries |
| Adoption (2026) | ~55% of traffic | ~45% of Google users |
Why IPv4 is still dominant
Despite IPv6 being standardized in 1998, IPv4 still carries the majority of Internet traffic. The main reasons:
- NAT "solved" the problem — Network Address Translation lets millions of devices share one public IPv4 address. This reduced the urgency to migrate.
- Migration cost — dual-stack (running IPv4 + IPv6 simultaneously) is expensive. Equipment, training, and testing all take time and money.
- IPv4 address market — organizations can buy/sell IPv4 blocks on the secondary market ($30–$50 per address in 2026), extending IPv4's useful life.
- Content availability — most content is accessible over IPv4; only ~30% of the Alexa Top 1000 is reachable over IPv6-only.
IPv6 adoption leaders
Countries with the highest IPv6 adoption rates (percentage of traffic served over IPv6):
The transition timeline
- 1981 — IPv4 defined in RFC 791.
- 1998 — IPv6 standardized in RFC 2460.
- 2011 — IANA allocates the last IPv4 /8 blocks to APNIC. Top-level free pool exhausted.
- 2012 — World IPv6 Launch day (June 6). Major ISPs and content providers enable IPv6 permanently.
- 2014–2015 — LACNIC and ARIN free pools exhausted.
- 2019 — RIPE NCC runs out of IPv4 addresses.
- 2026 — ~45% of global traffic uses IPv6. Full transition remains years away.
Explore IPv4 data
WorldIP.io tracks every allocated IPv4 address, ASN, and organization. IPv6 addresses get geolocation, ASN, organization, scanned reverse DNS and blocklist status: try 2001:4860:4860::8888.
