Starlink + UniFi + Homey Pro: How to Enable Direct Connection via IPv6 (Bypassing CGNAT)

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Hi everyone,

I wanted to share a successful setup for establishing a Direct Connection to Homey Pro (2023) while using Starlink, which is notorious for using CGNAT (Carrier-Grade NAT) on IPv4.

As many of you know, Port Forwarding on IPv4 is impossible with Starlink because we don’t have a public IP address. This usually forces Homey to fall back to the slower “Cloud Relay” connection.

However, I managed to get a fully working Direct Connection using IPv6 with a UniFi UDM SE. Here is how I did it, and a note for the Homey developers regarding the “Port Forwarding” UI.

My Setup

  • ISP: Starlink (Residential, Gen 2)

  • Router: UniFi UDM SE (OS 3.x, Network 8.x)

  • Device: Homey Pro 2023

Step 1: Enabling IPv6 on Starlink & UniFi

First, we need to get a valid IPv6 address since IPv4 is behind CGNAT.

  1. UniFi Internet Settings (WAN):

    • IPv6 Connection: DHCPv6

    • Prefix Delegation Size: 56 (Note: If 56 doesn’t work, try 64. I had to unplug/replug the WAN cable to force Starlink to lease a new IP).

  2. UniFi Network Settings (LAN):

    • IPv6 Interface Type: Prefix Delegation

    • Client Address Assignment: SLAAC / DHCPv6

Result: My Homey Pro received a valid global IPv6 address (starting with 2a0d:...).

Step 2: Opening the Firewall (The “New” Port Forwarding)

Since there is no NAT in IPv6, we don’t use traditional “Port Forwarding.” Instead, we need to open the Firewall to allow traffic directly to Homey.

In UniFi Network > Security > Traffic Rules:

  • Action: Allow

  • Category: Internet

  • Traffic Direction: Traffic Coming FROM Internet (Source: External/Any)

  • Destination: Homey Pro (or its specific IPv6 Address)

  • Port: 443

  • Protocol: TCP

Step 3: Verification (The Important Part)

After applying these settings, I tested the connection using an external IPv6 Port Checker (like port.tools).

  • Target: Homey’s Global IPv6 Address

  • Port: 443

  • Result: OPEN / SUCCESS :white_check_mark:

I verified this by turning off Wi-Fi on my phone (using 4G/5G). The Homey App connects instantly, confirming a Direct Connection.

:warning: A Note to Homey Developers / Feature Request

This is the tricky part that confuses users. Even though my Direct Connection works perfectly via IPv6:

  1. I went to Homey App > Settings > Port Forwarding.

  2. I enabled it and entered port 443.

  3. The app threw an error: “Not Working. Homey Pro couldn’t be reached…”

The Reason: The Homey App seems to only check the IPv4 address (which is 192.168.1.x internally and 100.x.x.xexternally via CGNAT). It does not seem to validate or recognize that the IPv6 path is actually open and working.

My Request: Could you please update the Port Forwarding settings page to support and validate IPv6 addresses? Currently, we have to ignore the “Error” message and the red toggle in the app, even though the system is working perfectly. Adding native IPv6 support to this UI would be a game-changer for Starlink and Fiber users worldwide.

Hope this guide helps anyone struggling with Starlink and remote access!

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