Unless you pay your internet provider extra for a "Static IP", your home's public IP address changes randomly. Dynamic DNS (DDNS) solves this by giving your home a permanent web address that automatically tracks those changes.
Overview
If your public IP is 72.14.x.x today, you can connect your WireGuard VPN to it. But if Comcast changes it to 73.18.x.x tomorrow, your VPN will break because it's looking for the old address.
DuckDNS is a free service that gives you a subdomain (like myhouse.duckdns.org). A small app on your LocalNode "phones home" to DuckDNS every 5 minutes, telling it your current IP address. This ensures myhouse.duckdns.org always points to your house.
Now we need to tell the LocalNode to start updating that domain.
Go to your LocalNode dashboard at http://localnode.local.
Click on the DuckDNS app icon.
A simple configuration panel will appear.
Subdomain(s): Enter the domain you just created (e.g., smithfamily). Do not include the .duckdns.org part.
Token: Paste the token from the DuckDNS website.
Click Save & Start.
The app is now running invisibly in the background. If your ISP changes your IP address at 2:00 AM, the app will notice at 2:05 AM and instantly update DuckDNS to fix the routing.
Step 3: Updating your VPN/Apps
You must now tell your external apps to use the domain name instead of the IP address.
For WireGuard:
Open the WireGuard app on your phone.
Tap your connection profile and tap Edit.
Change the Endpoint field from your hardcoded IP address to your new domain.
Example: Change 72.14.x.x:51820 to smithfamily.duckdns.org:51820.
Tap Save.
💡 Tip: If you use Nginx Proxy Manager to expose Jellyfin to the web without a VPN, you can use your new DuckDNS domain to generate the free Let's Encrypt SSL certificate!