# IPv6 ULA Generator Guide

Generate a random IPv6 unique local address prefix.

- Tool: https://ilham.dev/tools/ipv6-ula-generator/
- Guide URL: https://ilham.dev/guides/ipv6-ula-generator/
- Tool guides index: https://ilham.dev/guides/tools/
- Broader guide: Network Debugging Notes (https://ilham.dev/guides/network-debugging/)

## What it does

Generate a random IPv6 unique local address prefix in fd00::/8, following RFC 4193, for a network that should never be routed on the public internet.

## Use the tool

Open https://ilham.dev/tools/ipv6-ula-generator/, add the input the tool asks for, run it, and check the output before using it elsewhere.

## Input and output

- Input: text.
- Output: text.
- Category: Network.

## Privacy and processing
Processing happens locally in your browser. This tool does not upload the input to ilham.dev.

## Questions

### What is the difference between fc00::/7 and fd00::/8?

The whole range is fc00::/7. The fd00::/8 half is where the 40-bit global ID is generated locally rather than assigned by a registry, which is the practical choice.