How to set up DDNS in a UniFi Gateway

Ever wanted to access your UniFi network when you’re not home or at the office? Maybe you’ve got a server, a camera system, or even your UniFi Controller running locally. The problem? Your public IP changes.

That’s what most ISPs do unless you pay extra for a static IP.

That’s where Dynamic DNS (DDNS) comes in. It gives you a consistent hostname that updates automatically when your IP changes. You set it up once, and you're good. This guide walks you through how to set up DDNS on a UniFi Gateway, whether you’re using a UDM, UDM Pro, or USG.

Let's dive in !!

What is DDNS?

DDNS stands for Dynamic Domain Name System. It’s like regular DNS, but instead of mapping a domain name to a fixed IP address, it updates dynamically. If your ISP changes your IP, DDNS updates it so your domain still points to the right place.

Let’s say you use myunifisite.ddns.net. When your IP changes, DDNS makes sure that name always points to your home or office.

Why use DDNS?

Here are a few scenarios where DDNS makes sense:

• Accessing a home server remotely: You run a Plex or file server at home and want to stream while you're out.
• Remote SSH or RDP: You manage devices remotely and need a fixed address.
• Surveillance cameras: You want to check your camera feeds from your phone.
• UniFi Controller access: You run your own controller locally and need to adopt new devices or check in when you're away.

Without DDNS, you’d need to find your IP address every time it changes. That gets old fast.

What you need before you start

1. A working UniFi Gateway (UDM, UDM Pro, USG)
2. A DDNS provider (like No-IP, DynDNS, or DuckDNS)
3. Your UniFi Controller (Cloud Key, Dream Machine, or hosted—like UniHosted)
4. Your WAN IP must be public (no CGNAT)

If your ISP uses CGNAT, you won’t be able to access your gateway directly unless you use a VPN or reverse proxy setup.

Choose a DDNS provider

There are a bunch out there. Pick one based on your needs.

Popular options:

• No-IP (https://www.noip.com): Free option, works well with UniFi.
• DynDNS (https://www.dynu.com): Another solid choice.
• DuckDNS (https://www.duckdns.org): Free, but not built into UniFi, requires a custom URL.
• Afraid.org: More advanced, but flexible.

Once you sign up, you’ll create a hostname like myoffice.ddns.net.

How to set up DDNS on UniFi Gateway

Let’s walk through it step by step.

Step 1: Log into your UniFi Controller

Use your browser and log in. If you're using UniHosted, just head to your dashboard and launch your site.

Step 2: Go to Internet settings

In the new UI (UniFi OS), do this:

• Click Settings on the left
• Go to Internet
• Click your WAN interface (usually WAN1)

This opens up the WAN configuration panel.

Step 3: Enable DDNS

Scroll down until you find Advanced. Click it to expand more options.

• Find the section called Dynamic DNS
• Click Create New Dynamic DNS

Step 4: Enter your DDNS details

Now you fill out the form:

• Service: Pick your provider (No-IP, DynDNS, or “Custom”)
• Hostname: This is your custom DDNS domain, like myoffice.ddns.net
• Username: Usually your DDNS account login
• Password/Key: Depends on the provider. Sometimes it’s your account password, sometimes an API key
• Interface: Leave it on WAN1

If you’re using a provider like DuckDNS, you’ll need to use the “Custom” option and provide a full update URL. That URL will look something like this:

https://www.duckdns.org/update?domains=myoffice&token=YOURTOKEN&ip=

Paste that into the Server URL field.

Click Apply Changes once everything is filled in.

Step 5: Test it

Wait a few minutes, then visit your DDNS address in a browser or ping it from your terminal:

ping myoffice.ddns.net

If it resolves to your current public IP, you’re good.

To confirm further:

• Visit your DDNS provider’s dashboard
• Check the current IP address
• Make sure it matches what your ISP gave you

You can check your current IP at https://whatismyipaddress.com/

What if it doesn’t work?

If your DDNS isn’t updating, here are some things to check:

• Wrong credentials: Double-check your username, password, or token.
• IP address is private: If your WAN IP is 192.168.x.x or 10.x.x.x, you’re behind CGNAT.
• Firewall blocking traffic: Make sure outbound ports are open.
• DDNS provider blocking updates: Some free providers throttle updates. Wait and try again later.

If you're using a custom provider like DuckDNS, test the update URL in your browser. It should return something like “OK” or “good”.

Bonus: Add port forwarding

DDNS only gets you to your public IP. If you want to access services inside your network, you need to forward ports.

Example: You run a web server on port 8080.

1. Go to Settings > Firewall & Security > Port Forwarding

2. Create a new rule
   • Name: WebServer
   • Port: 8080
   • Forward IP: your device’s IP
   • Forward Port: 8080
3. Save and apply

Now, if you visit myoffice.ddns.net:8080, you’ll hit your server, assuming your ISP allows that.

Use DDNS with UniFi VPN

Let’s say you want to set up a VPN and use DDNS to connect. It’s easy:

1. Enable L2TP VPN Server under Teleport & VPN
2. Use your DDNS domain as the server address
3. Add a user and password
4. Connect remotely using your OS’s built-in VPN client

Your DDNS address will always point to your gateway, even if your IP changes.

Use DDNS to adopt UniFi devices

If you're managing a remote UniFi site and want to adopt devices, use DDNS to connect to your UniFi Controller.

Let’s say your controller is running at mycontroller.ddns.net.

On the remote device (AP, switch, etc.), SSH in and run:

set-inform http://mycontroller.ddns.net:8080/inform

This tells the device to phone home to your controller, even if the IP keeps changing.

Things to keep in mind

• Update interval: UniFi will update your DDNS when your IP changes. It’s not instant, but usually within a few minutes.
• Free accounts may expire: Some providers like No-IP require you to confirm the hostname every 30 days.
• Security: Don’t expose sensitive services like SSH or RDP without proper firewalls or VPNs.

Troubleshooting common issues

1. My hostname doesn’t resolve

• Check your DDNS provider’s dashboard
• Make sure the account is active and hasn’t expired
• Double-check the hostname in your UniFi settings

2. The wrong IP is showing

• Make sure your gateway is using a public IP
• Restart your gateway or force an update via the DDNS provider

3. Port forwarding isn’t working

• Check if the port is open using tools like canyouseeme.org
• Make sure the device’s IP hasn’t changed (use DHCP reservations)
• Verify the device is actually listening on that port

Final thoughts

Setting up DDNS on your UniFi Gateway is one of those things that takes just a few minutes, but makes your life way easier in the long run. Whether you're running servers, managing remote gear, or just want to VPN into your network, having a reliable, consistent domain name you can always reach is a big deal.

And if you're tired of messing with IPs, firmware updates, or port forwarding rules, let us handle it. At Unihosted, we manage your UniFi Controller in the cloud, keep it backed up, optimized, and always accessible, so your network stays online and secure.