To restrict access to account1, you need to enable the firewall and virtual network settings on the storage account. This allows you to specify which networks can access the storage account. By selecting Selected networks, you can block all access from the public internet and only allow access from the specified networks. By adding VNet1, you can allow access from the virtual network that contains VM1. You do not need to add the on-premises IP address range or enable the service endpoint option, as these are not required for uploading the disk files to the storage account. You do not need to allow trusted Microsoft services, as this is not relevant for the scenario. Then, Reference: [Configure Azure Storage firewalls and virtual networks] [Upload a generalized VHD to Azure]