
KmDDNS
Automatically keeps your KmDDNS record updated with your Minecraft server's IP and port.
About this Mod
Automatically keeps your KmDDNS record up to date so players can always find your server — even when your IP changes.
No router config. No static IP. Just install and run.
What it does
KmDDNS gives your Minecraft server a permanent address like myserver.ddns.kmathers.co.uk. Whenever your server starts, the mod checks your current public IP and updates the DNS record automatically. Players always connect to the same address.
Tunnel mode takes this further — if you can't or don't want to forward ports, the mod connects to a relay that routes player traffic through KmDDNS infrastructure. No port forwarding required at all.
Features
- Keeps your subdomain pointing at your current IP automatically
- Sends your server's MOTD and player count to the KmDDNS API (shown on the lookup page)
- Tunnel mode — no port forwarding needed, traffic is proxied through a relay
- In-game setup wizard — register or configure everything without leaving the game
/kmddns statusto see your current address, IP, and connection state at a glance- Configurable heartbeat interval, port, and tags
Setup
1. Get a subdomain
Run /kmddns setup in-game to open the wizard. You can:
- Register a new subdomain — pick a name and get a token on the spot
- Use an existing token — if you already have a KmDDNS account
The wizard walks you through port detection, update interval, and whether to use tunnel mode. When you confirm, it saves the config and starts immediately.
2. That's it
Your server will now appear at yourname.ddns.kmathers.co.uk. Players connect using that address.
Tunnel mode
If you're behind CGNAT, a strict firewall, or just don't want to mess with port forwarding, enable tunnel mode during setup.
In tunnel mode:
- The mod keeps a WebSocket connection open to KmDDNS
- When a player connects to your subdomain, the relay routes them through to your server
- Your server doesn't need to be reachable from the internet directly
Enable it during /kmddns setup, or set tunnel = true in the config and toggle it on via the API.
Commands
| Command | Description |
|---|---|
/kmddns status |
Show current IP, subdomain, tunnel state, and last update time |
/kmddns setup |
Open the interactive setup wizard |
/kmddns setup token <token> |
Configure with an existing token |
/kmddns setup new |
Register a new subdomain |
Config
The config file is created automatically at config/kmddns.toml on first launch.
[kmddns]
enabled = true
token = "your-token-here"
api_base = "https://ddns.kmathers.co.uk/v1"
port = 0 # 0 = auto-detect from server.properties
update_interval = 300 # seconds between heartbeats (minimum 30)
tags = ["minecraft"]
metadata_motd = true # send server MOTD to the API
metadata_player_count = true
log_updates = true
tunnel = false # set true to use tunnel mode
Requirements
- Server-side only — players do not need this mod
- Fabric or NeoForge
- Minecraft 1.21.1, 1.21.4, 1.21.5, or 1.21.11
- A KmDDNS account (free, created via
/kmddns setup new)
A quick note
I build these tools for fun and for the community. Keeping everything running does have real maintenance costs, and even $1 goes a long way.
If you enjoy the tools and want to give back, you can support me here: Buy me a coffee. No pressure either way — thanks for being here.
Available Versions
How to Install KmDDNS on Your Server
Order Server
Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).
Set fabric Loader
In the panel under "Egg", select the fabric loader and matching Minecraft version (1.21.11).
Install Mod
Open the mod browser in the dashboard and search for "KmDDNS". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.21.11, 1.21.10, 1.21.9 (+8 more)
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
KmDDNS server crashes on startup – what to do?
Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.21.11). You can switch loaders with one click in the panel.
Is KmDDNS compatible with fabric and neoforge?
KmDDNS officially supports fabric, neoforge for Minecraft 1.21.11, 1.21.10, 1.21.9. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with KmDDNS – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if KmDDNS consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
Rent Modded Server
Install KmDDNS with just one click on your server.