Explanation: You can log network traffic that flows through an NSG with Network Watcher's NSG flow log capability. In the Azure portal, enable Network Watcher Register Insights provider. NSG flow logging requires the Microsoft.Insights provider. Enable NSG flow log. NSG flow log data is written to an Azure Storage account, Subscription1 has storage. Reference: https://docs.microsoft.com/en-us/azure/network-watcher/network-watcher-nsg-flow-logging-portal