Azure Cosmos DB supports IP-based access controls for restricting database access
Azure Cosmos DB now supports IP-based access controls for restricting access to a database account. This IP-based access control model is very similar to the firewall rules of a traditional database system and provides an additional level of security to the Azure Cosmos DB database account.
With this model, you can configure a Azure Cosmos DB database account to be accessible only from an approved set of machines and/or cloud services. To configure the IP access control policy, file a free Help + Support ticket in the Azure portal by using the instructions in the Azure Cosmos DB firewall support article.