Northbound/Assets/Scripts/IMMEDIATE_FIX.md

Connection Issue: Immediate Action Plan

Your Problem

Teammate sees "CONNECTED" but gets "Failed to connect to server" error.

Root Cause (Most Likely)

Windows Firewall is blocking Unity/Build even with port forwarding done correctly.

FIX IN 3 STEPS

Step 1: Add Debug Components (1 minute)

Add these to your NetworkManager GameObject in BOTH Host and Client scenes:

1. ConnectionDiagnostics (automatic check)
2. NetworkDebugger (detailed logs)
3. NetworkConnectionFixer (auto-fixes issues)

Step 2: Fix Firewall (2 minutes)

Run PowerShell as Administrator, paste this:

# Allow Unity Editor
netsh advfirewall firewall add rule name="Unity Editor" dir=in action=allow program="C:\Program Files\Unity\Hub\Editor\*\Unity.exe" enable=yes profile=any

# Allow your game build (update path!)
netsh advfirewall firewall add rule name="Northbound Game" dir=in action=allow program="D:\Northbound\Build\Northbound.exe" enable=yes profile=any

# Allow port 7777
netsh advfirewall firewall add rule name="Unity Port 7777" dir=in action=allow protocol=TCP localport=7777 enable=yes profile=any

Step 3: Verify Port Forwarding (1 minute)

Go to: https://www.yougetsignal.com/tools/open-ports/

• Enter your PUBLIC IP
• Enter port 7777
• Should say: "Port 7777 is open"

If "Closed", your router port forwarding is wrong.

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Quick Diagnostics

In Unity Editor (Play Mode):

1. Add ConnectionDiagnostics to NetworkManager
2. Right-click component → "Run Diagnostics"
3. Check console for errors/warnings

Common Diagnostics Results:

• ✅ "System Healthy": Configuration is good, issue is network/firewall
• ⚠️ "Player Prefab NOT assigned": Assign player prefab in NetworkManager
• ⚠️ "Connect timeout too low": ConnectionDiagnostics fixes this automatically
• ❌ "NetworkManager not found": Add NetworkManager to scene

If Still Not Working:

Test 1: Local Connection

Host connects to 127.0.0.1 (same instance)

• ✅ Works = Good setup, issue is network
• ❌ Fails = Project setup issue

Test 2: LAN Connection

Host shares 192.168.x.x IP (same WiFi)

• ✅ Works = Good LAN, issue is port forwarding for internet
• ❌ Fails = Firewall blocking local connections

Test 3: Internet Connection

Host shares PUBLIC IP with teammate

• ✅ Works = Fixed!
• ❌ Fails = Port forwarding or remote firewall

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What Console Should Show

Host (Working):

[ConnectionDiagnostics] System Healthy
[NetworkConnectionFixer] Network fixes applied
[NetworkDebugger] Server Started Successfully
[NetworkDebugger] Listening on: 0.0.0.0:7777
[NetworkDebugger] Client Connected: 1
[ConnectionHandler] 클라이언트 1 승인됨
[ConnectionHandler] 플레이어 1 스폰됨

Client (Working):

[ConnectionDiagnostics] System Healthy
[NetworkConnectionFixer] Network fixes applied
[NetworkDebugger] Connection Approval Request
[NetworkDebugger] Approval Response: Approved: true
[NetworkDebugger] Client Connected: 0

Client (Broken - Your Case):

[ConnectionDiagnostics] System Healthy
[NetworkConnectionFixer] Network fixes applied
[NetworkDebugger] Connection Approval Request
<color=red>[NetworkDebugger] TRANSPORT FAILURE!</color>
Failed to connect to server

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Tools Created for You

File	Purpose	How to Use
ConnectionDiagnostics.cs	Auto-checks configuration	Add to scene, right-click "Run Diagnostics"
NetworkDebugger.cs	Shows detailed connection logs	Add to scene, watch Console during connection
NetworkConnectionFixer.cs	Fixes common timeout issues	Add to scene, right-click "Fix All Known Issues"
PublicIPHelper.cs	Gets your public IP automatically	Add to scene, see Inspector

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Most Likely Issue: Firewall

Even with correct port forwarding, Windows Firewall blocks:

1. ✅ Port 7777 may be open (router allows it)
2. ❌ But Windows Firewall blocks the application using that port

Solution: Allow Unity and your game through firewall (Step 2)

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Alternative: Use Hamachi/VPN

If port forwarding is too complex:

1. Both install Hamachi: https://www.vpn.net/
2. Join same Hamachi network
3. Use Hamachi IP (25.x.x.x) instead of public IP
4. No port forwarding needed!

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Share This for Help

If issue persists, share screenshots/logs:

1. ✅ NetworkManager Inspector (screenshot)
2. ✅ Unity Transport settings (screenshot)
3. ✅ Console log (Host) - after connecting
4. ✅ Console log (Client) - after connection attempt
5. ✅ Port checker result (screenshot)
6. ✅ Windows Firewall rules list (screenshot)

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Summary

1. Add debug components (1 min)
2. Fix firewall (2 min) - MOST IMPORTANT
3. Verify port forwarding (1 min)
4. Test with console logs

If all this fails, the issue is likely:

• Port forwarding is wrong (verify with online tool)
• Different Unity/Netcode versions between you and teammate
• Antivirus/security software blocking

Good luck! 🎮