---
date: 2025-04-12T21:18:30+01:00
draft: false
title: Setting up Unique Local Addresses (ULA) on OPNsense
tags:
  - Post
  - IPv6
  - Networking
---
Setting up unique local addresses on OPNsense is very easy however not very well documented. This is how to configure then

Firstly create a unique local IPv6 prefix. This should be according to RFC4193.  You can use this website (or similar websites) to generate the address.

https://www.unique-local-ipv6.com/#

Next, create a virtual IP on an interface with the desired IP for said interface. From the generator you will receive a /48 network, pick a subnet from this address range for your local network.

For example I used the virtual IP `fd7a:18a6:838d::1/64` for my LAN interface. 

The router should be reachable using the address configured an should router advertisements be configured correctly then nodes on that network should generate a their own unique local address on that network!