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IPv6 ULA Generator - Create RFC 4193 Unique Local IPv6 Prefixes

Generate standardized IPv6 Unique Local Address (ULA) /48 prefixes based on RFC 4193 specifications for private internal networks.

This tool runs in your browser.
Processed locally in your browser.

How to use

  1. 01Enter or upload the source data.
  2. 02Run the tool in your browser.
  3. 03Review, copy, or download the result.

FAQ

What is an IPv6 Unique Local Address (ULA)?

ULAs (prefix fd00::/8) are the IPv6 equivalent of IPv4 private addresses (RFC 1918), non-routable on the public internet and intended for internal subnets.

How does RFC 4193 prevent address conflicts across LANs?

It mandates a pseudo-random 40-bit Global ID following the fd prefix, making accidental collisions between merged private networks statistically negligible.

Can these generated prefixes be used in production VPNs and routers?

Yes. The resulting /48 block can be partitioned into 65,536 /64 subnets for OpenWrt, Docker container clusters, and WireGuard tunnels.