Port Monitoring

Validate that required service ports are reachable and accepting connections, surfacing routing and availability issues early. Port monitoring is the right check for services that do not speak HTTP - mail servers, VPN endpoints, database listeners and other networked services that simply need to be accepting connections.

What it checks

A port monitor attempts a TCP connection to a host and port on a schedule and reports whether the connection succeeds:

• Service reachability - whether the port is open and accepting connections, the core signal that a service is listening.
• Closed or blocked ports - detection of ports that have stopped accepting connections before that failure reaches production.
• Routing issues - connectivity problems between the monitor location and the host, surfaced as failed or slow connections.
• Dependency health - confirmation that the networked services upstream systems rely on are available as expected.

Configuration

Port monitors are configured around the connection you want to test:

• Host - the hostname or IP address of the service to check.
• TCP port - the port number to connect to, for example 25 for SMTP or 5432 for Postgres.
• Check interval - how often the monitor attempts to connect.
• Timeout - how long to wait for the connection to be established before the check is recorded as failed.