Port Monitoring

Confirm every service port is reachable.

Web monitoring tells you whether a web server is responding. Port monitoring tells you whether every service behind it is running. Database servers, mail servers, SSH, custom application ports — NetTests probes each TCP port you configure and alerts you immediately when a service stops accepting connections.

Services can fail without taking the web server down

A web server can return 200 responses while a critical backend service — a database, a cache, a message queue — is completely unreachable. Users might see an application that appears to load correctly but fails silently when it attempts to retrieve or store data. Port monitoring checks the services your application depends on, not just the front door.

Port monitoring is also essential for infrastructure that isn't web-facing: database servers, LDAP directories, message brokers, and internal APIs that only need to be reachable from within your network. These services rarely have URL-based health checks, but a TCP port check can verify reachability with no additional configuration required.

Key features

TCP port checks

Verify that any TCP port — 22, 25, 443, 3306, 5432, custom — is open and accepting connections.

Service banner capture

Capture the service banner on connection to verify that the correct service is running on each port.

Connection timeout monitoring

Alert when connection time exceeds threshold — detect degraded services before they fail entirely.

Instant alerting

Receive notifications immediately when a port stops responding or becomes unreachable.

Free port diagnostic tools

Monitor every port your services depend on

NetTests probes your TCP ports on a schedule and alerts you immediately when a service stops accepting connections.

Start monitoring free →
No credit card required  ·  Free plan available