Know when critical service ports become unreachable

What port monitoring checks

Port monitoring checks whether a selected host and port can be reached from a monitoring location. It can help reveal when a service is no longer accepting connections, a network path has changed, or a listener is unavailable. This is useful for services that do not have a public web interface.

A reachable port does not necessarily mean the application behind it is healthy or returning useful results. Use API monitoring for HTTP endpoints and application-level response behavior, and use a TCP check when you need to monitor a service connection directly.

Select ports with clear ownership

List the hosts and ports that support important services, who owns each one, and what a failed check would mean for users. Focus on the ports your team is authorized to monitor and operate; avoid creating checks for systems outside your organization’s control.

Document the expected service, contact, and first troubleshooting steps in a runbook. Choose check coverage that fits each service’s priority and confirm the current monitor limits on the pricing page.

Investigate a port alert with context

When a check fails, verify the hostname and port, then review recent service restarts, network changes, and access-control updates. If the service is reachable from some locations but not others, investigate the network path before assuming the service is completely down.

Route the alert to the team responsible for the service through an integration. Pair port checks with website monitoring and a status page when you need both technical detection and clear customer updates.