This check is off by default. Enable it and list targets under Active checks on the monitor.
How it works
Every 5 minutes, we open a TCP connection to every target. We send no data: a successful handshake means the service is accepting connections. Use this check for services that do not speak HTTP, such as databases, mail servers, SSH or game servers. A failure is confirmed from our other locations before it counts.
Settings
| Setting | Default | What it does |
|---|---|---|
| Targets | — | host:port entries, or a bare port on the monitored host, separated by commas or spaces, e.g. db.example.com:5432, 22. |
| Interval minutes | 5 |
How often to connect. |
| Timeout seconds | 5 |
How long to wait for each connection. |
| Alert after minutes | 2 |
How long a port must be closed before we alert you. |
Statuses
| Status | Meaning |
|---|---|
| OK | Every target accepted a connection. |
| Failed | A target refused the connection, timed out or is not a valid target, and other locations confirmed it. |
By default you are notified of warnings and failures.
Fixing common problems
- Timed out: a firewall is probably dropping the connection. Allow our IP addresses on that port.
- Refused: nothing is listening on the port. Check that the service is running and bound to a public interface, not only to
127.0.0.1. - Exposure: if a database should not be reachable from the internet, do not monitor it here. Keep it closed and let the Port scan check confirm it stays closed.