IPv6 — The Next Internet Protocol

IPv6 replaces IPv4, whose 4.3 billion addresses are exhausted. IPv6 offers 128-bit addresses — practically unlimited — plus built-in security.

Address Format

2001:0db8:85a3::8a2e:370:7334
# Leading zeros omitted, :: for zero chains

Benefits

No NAT needed — every device gets a real public address. SLAAC configures addresses automatically. Built-in IPsec. More efficient headers.

Migration

Dual-stack (both protocols in parallel) is the standard path. DNS returns AAAA and A records; systems prefer IPv6.

Related: TCP/IP Basics · DNS Explained