Perform the following in the Azure Console:

1. Go to Storage Accounts
2. For each storage account, Click on the settings menu called Firewalls and virtual networks .
3. Ensure that you have elected to allow access from Selected networks
4. Add rules to allow traffic from specific network
5. Click Save to apply your changes

Perform the following in Azure Command Line Interface 2.0:

Use the below command to update default-action to Deny.

az storage account update –name <StorageAccountName> –resource-group
<resourceGroupName> –default-action Deny

References:

1. https://docs.microsoft.com/en-us/azure/storage/common/storage-network-security