A port check tests whether a specific network port on a host is accepting connections. Ports are virtual endpoints that allow network services to communicate. Each service typically uses a standard port number.
Common Uses
- Firewall Testing: Verify that firewall rules are configured correctly.
- Server Diagnostics: Check if a web server, database, or other service is running.
- Network Troubleshooting: Identify connectivity issues between systems.
- Security Auditing: Find open ports that might be security risks.
Understanding Results
- Open: The port is accepting connections — the service is running and accessible.
- Closed: The connection was refused — no service is listening on that port.
- Filtered/Timeout: The connection timed out — a firewall may be blocking access.