IPv6 ULA Generator
Generate a random RFC 4193 Unique Local Address prefix — IPv6's equivalent of a private IPv4 range like 192.168.x.x.
About this tool
A Unique Local Address (ULA) is IPv6's equivalent of the private address ranges you know from IPv4 (like 192.168.x.x or 10.x.x.x) — defined in RFC 4193, ULAs live in the fd00::/8 range and are meant for addressing inside a single site or organization, not routed on the public internet.
The 40-bit Global ID is generated randomly so that if two organizations' private networks are ever connected or merged, their address ranges are extremely unlikely to collide — unlike IPv4 private ranges, which very often overlap. Generate a Global ID once for your network and reuse the resulting /48 prefix everywhere; the Subnet ID field lets you carve out different /64 subnets (like 0001, 0002, and so on) from that same prefix for different VLANs or network segments.
Version 1.0.0