Ask this site's Cloudflare edge to connect to the public source IP it observes for your request. This does not test UDP, a private LAN, or arbitrary third-party hosts.
TCP and UDP use 16-bit port numbers from 0 through 65535; this interface accepts the user-port range 1 through 65535 and performs TCP checks only. Service labels below are conveniences based on commonly registered uses, not proof of which application is actually listening. Source: IANA Service Name and Port Number Registry.
| Port | Service | Description |
|---|---|---|
| 20-21 | FTP | File Transfer Protocol — used for transferring files |
| 22 | SSH | Secure Shell — encrypted remote access |
| 25 | SMTP | Simple Mail Transfer Protocol — sending emails |
| 53 | DNS | Domain Name System — translating domain names |
| 80 | HTTP | Hypertext Transfer Protocol — web traffic |
| 443 | HTTPS | Secure HTTP — encrypted web traffic |
| 3306 | MySQL | MySQL database server |
| 3389 | RDP | Remote Desktop Protocol — Windows remote access |
| 5432 | PostgreSQL | PostgreSQL database server |
| 8080 | HTTP Alt | Alternative HTTP port — often used for proxies |
Connected: The Cloudflare edge completed the TCP connection.
Failed: The connection promise rejected before the timeout; the result does not identify why.
Timed out: The attempt did not complete within five seconds; the result does not identify why.
Unavailable: The Cloudflare socket check could not run.
It attempts a TCP connection from the site's Cloudflare edge to the public host and port you enter. It does not scan UDP, private addresses, or the path from your own device.
Check ports relevant to the services you run. Common ones: 80/443 for web servers, 22 for SSH, 25 for email (SMTP), 3389 for Remote Desktop, 3306 for MySQL, and 8080 for alternate HTTP. If you're troubleshooting a specific service, check the port that service uses.
Connected means the edge completed the TCP connection. Failed means the promise rejected before timeout. Timed out means no completion within five seconds. Unavailable means the socket check could not run. The latter three statuses do not identify a cause.
Use the current instructions for your exact router and service. Port forwarding changes exposure to the public internet; restrict the source and authentication where possible, and do not expose database or administration ports without understanding the risk.