Which wireless deployment mode uses Flex architecture and permits Layer 2 client roaming between APs without a physical wireless controller?

Cisco Mobility Express is a controller-less solution that uses a virtual controller embedded within an access point (AP) to manage other APs. This allows for Layer 2 client roaming without a dedicated physical wireless controller, leveraging FlexConnect (formerly FlexConnect) for distributed data forwarding. Autonomous mode APs operate independently and do not support centralized management or seamless Layer 2 roaming between APs. Fabric mode is a newer architecture focused on policy-based automation and network segmentation, not specifically a controller-less roaming solution. Unified mode refers to traditional controller-based deployments where a physical controller manages APs and handles roaming.