What is the term for the switch in a stack that controls other switches?

The term for the switch in a stack that controls other switches is "Stack Master." In a stacked switch configuration, one switch is designated as the master or leader, which oversees the entire stack and manages the configuration and data traffic. This master switch is responsible for making administrative decisions and ensuring that the other switches in the stack synchronize their settings and configurations with it.

The stack master plays a crucial role in maintaining the operational integrity of the stack by managing tasks such as routing, forwarding, and the distribution of workload among the member switches. When the stack experiences changes, such as the addition or removal of switches, it is the stack master that coordinates these operations, ensuring minimal disruption to network functionality.

Other terms that may come to mind, such as "Stack Leader" or "Primary Switch," could imply a similar role, but they are not the official terminology used in networking standards to describe this function. "Switch Coordinator" is also not a recognized term within the context of switch stacking. Thus, "Stack Master" is the correct and most widely accepted term for the switch that takes on this controlling role within the stack.