Which mechanism is specifically designed to control traffic between virtual private clouds (VPCs) in a cloud environment?

The mechanism designed specifically to control traffic between virtual private clouds (VPCs) in a cloud environment is the network access control (NAC) lists. NAC lists, often referred to as security groups or access control lists (ACLs) in various cloud platforms, allow administrators to define rules that manage inbound and outbound traffic to the VPCs. By specifying which IP addresses or CIDR ranges are allowed or denied access, these lists provide a granular level of security and control, essential for maintaining the integrity and confidentiality of the data flowing between different VPCs.

Understanding the role of NAC lists is crucial in a cloud architecture because they facilitate secure communication while allowing flexibility in traffic management. This is particularly important in multi-cloud environments or when managing complex networks that require strict data governance and security policies. The ability to define and manage these lists dynamically is a key feature in modern cloud security practices.