Free tools
Port checker
Check one public TCP port from the named.network point of view. This is a consented reachability test, not a broad scan and not a vulnerability assessment.
This endpoint is rate limited per network and per target so it cannot be reused as a broad scanner.
Suggested next step
If the port is reachable and it fronts an app like n8n, Home Assistant, Grafana, Portainer, or WordPress admin, the next move is usually not “leave it there.” It is create a workspace and protect the app behind named.network.