Is a server port reachable?

Short answer Test the service’s TCP port instead of relying on ping.

When to use it

When the host answers ping but the application is unreachable.

Single port

Test-NetConnection <SERVER> -Port 443 -InformationLevel Detailed

Note

Read TcpTestSucceeded.

Several ports

80,443,3389 | ForEach-Object {Test-NetConnection <SERVER> -Port $_ -WarningAction SilentlyContinue | Select-Object ComputerName,RemotePort,TcpTestSucceeded}

Note

Test only ports that are relevant.

Caution

This does not validate UDP, and an open port does not prove application health.