If a rule shows as Unmapped or does not work from outside your network, use the checks below.
1. Confirm the service is running
Port Mapper publishes the port, but the app, game, or server must also be running on your Mac. Start the service first, then refresh or re-publish your rules.
2. Check the port numbers
- Make sure the internal port matches the port used by the service on your Mac.
- Make sure the external port is the port you want others to connect to.
- Ports must be between 1 and 65535.
- Avoid using the same external port for multiple services.
3. Check the protocol
If the rule uses the wrong protocol, connections may fail even when the port number is correct. Check the service documentation and choose TCP, UDP, or both as required.
4. Allow local network access
Port Mapper needs local network access to find your router and publish mappings. If this permission was denied, open macOS System Settings and allow local network access for Port Mapper.
5. Check router compatibility and settings
Your router must allow automatic port mappings. Some routers disable this feature, restrict it to certain devices, or require a restart after settings are changed.
If your router does not allow automatic mappings, you may need to create the port forwarding rule manually in your router settings.
6. Re-publish your rules
- Open Port Mapper.
- Choose Troubleshooting in the menu bar.
- Choose Re-Publish Ports.
You can also press Command + Option + P.
7. Check firewalls and network restrictions
A mapped port may still be blocked by firewall settings, security software, router rules, or your internet provider. If the rule shows as mapped but connections still fail, check these settings as well.