MU Online server network setup: port forwarding and Hamachi

To accept players from the internet, your MU Online server needs proper network configuration. Traffic arriving from players must find a clear path from the internet to your server PC, through your router, and past Windows Firewall.

What ports MU Online uses

IDENTIFY YOUR SERVER'S PORTS:

CHECK YOUR CONNECTSERVER.INI:
→ Open the MuServer folder → ConnectServer → ConnectServer.ini
→ Look for: Port = 44405  (or whatever your distribution uses)
→ This is the port players connect to first

CHECK YOUR GAMESERVER.INI:
→ Open GameServer → GameServer.ini
→ Look for: port = 55901  (or your distribution's value)

COMMON PORT DEFAULTS BY COMPONENT:

Component          | Protocol | Default Port | Open to Internet?
-------------------|----------|--------------|------------------
ConnectServer      | TCP      | 44405        | YES (players connect here)
GameServer         | TCP      | 55901        | YES (game traffic)
Website (HTTP)     | TCP      | 80           | YES (if site is on same PC)
Website (HTTPS)    | TCP      | 443          | YES (if SSL is configured)
SQL Server         | TCP      | 1433         | NEVER (local only)
MySQL              | TCP      | 3306         | NEVER (local only)
RDP (if VPS)       | TCP      | 3389         | Only from your IP (see RDP tutorial)

Setting up port forwarding (step by step)

PORT FORWARDING GENERAL PROCEDURE:

STEP 1 — FIND YOUR LOCAL IP:
→ On the server PC: Win + R → cmd → type: ipconfig
→ Look for "IPv4 Address" under your network adapter
→ Example: 192.168.1.100 (this is your PC's local IP on your network)
→ Note: this local IP can change — you should set a STATIC local IP
  (see "Set static local IP" section below)

STEP 2 — ACCESS YOUR ROUTER'S ADMIN PANEL:
→ Open browser on the server PC
→ Go to: 192.168.1.1 or 192.168.0.1 (most routers use one of these)
→ If neither works: check the label on your router for the admin URL
→ Log in with your router's admin username and password
   (default is usually admin/admin or admin/password — change this!)

STEP 3 — FIND PORT FORWARDING:
→ TP-Link: Advanced → NAT Forwarding → Virtual Servers
→ D-Link: Advanced → Port Forwarding
→ Netgear: Dynamic DNS → Port Forwarding/Port Triggering
→ Asus: WAN → Virtual Server / Port Forwarding
→ Intelbras: NAT → Port Forwarding (Redirecionamento de Portas)

STEP 4 — ADD THE PORT FORWARDING RULES:
Add one rule for each port:

Rule 1 — ConnectServer:
   External Port: 44405 | Internal IP: 192.168.1.100 | Internal Port: 44405 | Protocol: TCP

Rule 2 — GameServer:
   External Port: 55901 | Internal IP: 192.168.1.100 | Internal Port: 55901 | Protocol: TCP

Rule 3 — Website (if applicable):
   External Port: 80 | Internal IP: 192.168.1.100 | Internal Port: 80 | Protocol: TCP

STEP 5 — SAVE AND REBOOT THE ROUTER

STEP 6 — SET STATIC LOCAL IP ON THE SERVER PC:
→ Control Panel → Network and Internet → Network Connections
→ Right-click your network adapter → Properties → IPv4 → Properties
→ "Use the following IP address":
   IP address: 192.168.1.100 (the same IP from ipconfig)
   Subnet mask: 255.255.255.0
   Default gateway: 192.168.1.1 (your router IP)
   DNS: 8.8.8.8, 8.8.4.4

Double NAT problem (modem + router)

WHEN YOU HAVE MODEM + ROUTER:

THE PROBLEM:
→ ISP's modem → your router → your PC (two layers of NAT)
→ Traffic from internet hits the modem's NAT first
→ The modem doesn't know to forward the traffic to your router
→ Your router never sees the traffic → port forwarding rules never activate

SOLUTION A — BRIDGE MODE (recommended):
→ Log into the modem's admin panel (usually at 192.168.0.1 or a different IP)
→ Find "Bridge Mode" or "PPPoE Passthrough" setting
→ Enable bridge mode → the modem stops doing NAT, your router handles everything
→ You may need to enter your ISP's PPPoE username/password on the router now
→ Port forwarding on the router now works correctly

SOLUTION B — PORT FORWARD ON BOTH DEVICES:
→ Forward the ports on the MODEM to your router's IP
→ Then forward the same ports on the ROUTER to your server PC
→ More complex but doesn't require bridge mode
→ Example:
  - Modem: Port 44405 → 192.168.0.2 (router WAN IP)
  - Router: Port 44405 → 192.168.1.100 (server PC IP)

SOLUTION C — DMZ ON THE MODEM:
→ In the modem settings: find "DMZ" or "Exposed Host"
→ Enter your router's WAN IP as the DMZ host
→ This sends ALL traffic from the internet to your router (security risk but simple)

Windows Firewall configuration

OPEN PORTS IN WINDOWS FIREWALL:

Port forwarding on the router only handles external traffic. Windows Firewall handles
traffic between the internet and the specific program on your PC. Both must be configured.

OPEN PORTS IN WINDOWS DEFENDER FIREWALL:
1. Start → Windows Defender Firewall → Advanced Settings
2. "Inbound Rules" → "New Rule..."
3. Rule Type: Port → Next
4. Protocol: TCP | Specific local ports: 44405, 55901, 80
5. Action: Allow the connection
6. Profile: check all three (Domain, Private, Public)
7. Name: "MU Online Server" → Finish

VERIFY THE FIREWALL RULE WORKS:
→ On the server PC: netstat -an | find "44405"
→ You should see: TCP 0.0.0.0:44405 LISTENING
→ If nothing shows: the ConnectServer isn't running on that port (check it's started)

Using Hamachi (friends-only network)

HAMACHI — VIRTUAL LAN FOR SMALL GROUPS:

WHAT HAMACHI DOES:
→ Creates a virtual private network (VPN) between PCs
→ Everyone on the network gets a Hamachi IP (e.g., 25.1.2.3)
→ Players connect to your Hamachi IP instead of your real IP
→ No port forwarding or router configuration needed

SETUP:
1. Download LogMeIn Hamachi (free for up to 5 computers in a network)
2. Install on the server PC
3. Create a network: choose a name and password
4. Share the network name and password with your friends/players
5. Each player installs Hamachi and joins your network using the name/password
6. Players see your Hamachi IP in the Hamachi panel
7. In the game client: set the ConnectServer IP to your Hamachi IP (e.g., 25.1.2.3)

LIMITATIONS OF HAMACHI:
→ Maximum 5 computers on the free plan (one "network")
→ Higher latency than a direct connection or VPS
→ Hamachi must be running on ALL players' PCs before they can connect
→ If Hamachi service goes down, no one can connect
→ Not suitable for a public server — only for closed groups

WHEN TO USE HAMACHI:
→ Testing the server with 2-4 friends before making it public
→ Private servers for small guilds
→ Temporarily while you configure port forwarding

Testing your connection from outside

VERIFY PLAYERS CAN CONNECT:

TEST FROM YOUR OWN NETWORK:
→ NOT valid — you'll connect to the local IP, not through the router's NAT
→ You can't properly test port forwarding from the same network

TEST FROM OUTSIDE (correct method):
→ Use your phone's mobile data (Wi-Fi off)
→ Try to connect to the server from your phone's browser or game client
→ Or use an online port checker: "check port 44405" search tools
   → Enter your public IP and port 44405 → should show "Open"

FIND YOUR PUBLIC IP:
→ Search "what is my IP" on any browser
→ Or in CMD: nslookup myip.opendns.com resolver1.opendns.com

TEST WITH TELNET (CMD):
→ On a different network: telnet your.public.ip 44405
→ If it connects (blank screen or a few characters): port is open
→ If it says "Could not open connection": port is blocked
→ Enable telnet in Windows Features if the command doesn't exist

Continue with the No-IP dynamic DNS tutorial (for giving your server a fixed hostname when your home IP changes), the common server errors tutorial (for diagnosing connection problems players report), and the server anti-DDoS tutorial (for protecting the ports you've opened from attack traffic).

Frequently asked questions