Hi, Sir
FlexStack-Plus technology creates a resilient single unified system (a stack) of
up to eight switches in a homogeneous stack and up to four switches in a mixed stack. With a stack bandwidth of up to 80 Gbps, the stack functions as a single switching unit that is managed by the stack master. If the stack master fails, a new stack master is elected, keeping the stack operational. The new stack master is elected based on factors such as stack member priority value or lowest MAC address.
http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/release_notes/OL30810.htmlCisco Catalyst 2960-S, 2960-X, and 2960-XR Stacking with FlexStack and FlexStack-Plus Technology: Description, Usage, and Best Practices
http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-2960-x-series-switches/white_paper_c11-728327.htmlThanks!