IPv6 is the sixth version of the Internet Protocol with 128-bit addresses. An IPv6 address looks like: 2001:db8::1.
IPv4 vs IPv6 Comparison
| Parameter | IPv4 | IPv6 |
|---|---|---|
| Address length | 32 bits | 128 bits |
| Total addresses | ~4.3 billion | 340 × 10^36 |
| NAT required | Yes | No |
| Auto-configuration | DHCP | SLAAC built-in |
Configure IPv6 via Netplan (Ubuntu 22.04+)
# /etc/netplan/01-netcfg.yaml
network:
version: 2
ethernets:
eth0:
dhcp4: true
dhcp6: false
addresses:
- "2001:db8:1::/64"
routes:
- to: "::/0"
via: "fe80::1"💡 Dual Stack: Modern servers run IPv4 and IPv6 simultaneously. Browsers automatically prefer IPv6 when available (Happy Eyeballs RFC 6555).