NETWORKS / SERVER CONNECTION TEST
TCP port checker
Check whether this server can establish a TCP connection to one public host and port, or a small list of explicit ports.
Public destination
Connection result
No connection tested yet.
Choose a destination and select Check TCP port.- Host
- TCP port
- Tested address
- Elapsed time
Connection attempted from this service’s server.
Read the result in context
An open result means this server established a TCP connection. A refusal suggests the port is closed from this server. This check does not identify the application running on that port.
A timeout does not prove that a port is closed. Filtering, routing, or an unavailable host can prevent a response. Your own connection may follow a different route.
The target is sent only when you submit a check. There is no automatic scan, port range, or saved check history. An explicit list runs one request at a time and returns separate results. A refusal, DNS error, TCP timeout and a port not checked after an earlier error are distinct outcomes; none of them identifies an application.