Which approach enhances Azure database security by defining which IPs can connect?

The approach of IP whitelisting in the firewall effectively enhances Azure database security by controlling which IP addresses are permitted to connect to the database. This method involves specifying a list of allowed IP addresses, meaning that only these addresses can establish a connection to the database. By limiting access in this way, organizations can reduce the risk of unauthorized access, as any connection attempt from an IP address not included in the whitelist is automatically blocked. This is particularly useful in protecting sensitive data and maintaining compliance with security best practices.

Other options like Network Access Control Lists and Role-based access control pertain to network configurations and user permissions rather than directly managing IP connections to the database. Application Gateway primarily serves as a web traffic load balancer and security layer for applications rather than focusing on IP connection management for databases. Therefore, IP whitelisting in the firewall stands out as the most direct method for enhancing security by regulating the specific IPs allowed access to an Azure database.