The connectivity check feature in Azure Network Watcher is in public preview. You can use Network Watcher to test a direct TCP connection from a virtual machine to a virtual machine, FQDN, URI, or IPv4 address.
Network scenarios are complex. They are implemented through Network Security Groups, firewalls, user-defined routes, and resources provided by Azure. Complex configurations make troubleshooting connectivity problems challenging. Network Watcher helps reduce the amount of time to find and detect connectivity problems. The returned results can provide insights into whether a connectivity problem is due to a platform or a user configuration problem. Connectivity can be checked with PowerShell, Azure CLI, and REST API.
Learn more about the feature in the service documentation.