TCP Port monitors
Confirms that a host is accepting TCP connections on a given port. Ideal for services that don't speak HTTP — databases, message brokers, mail servers, game servers and internal services.
Fields
| Field | Required | Description |
|---|---|---|
| Host | Yes | Hostname or IP, e.g. db.internal or 203.0.113.10. |
| Port | Yes | TCP port number, e.g. 5432. |
| Timeout (ms) | No | How long to wait for the connection before failing. Defaults to 5000. |
How the check passes
The check is UP when a TCP connection to host:port is established within the timeout. It's
DOWN if the connection is refused, times out, or the host is unreachable.
Examples
| Service | Host | Port |
|---|---|---|
| PostgreSQL | db.example.com |
5432 |
| Redis | cache.example.com |
6379 |
| SMTP | mail.example.com |
25 |
Note
A TCP check only proves the port is open — not that the service behind it is healthy. For application-level checks, pair it with an HTTP / API monitor.