To instantly create a stack, onboard the switches into 
ExtremeCloud IQ using the
                    
ExtremeCloud IQ mobile app. Unbox the switches, connect the
                stacking/power/uplink cables, and push the 
Mode button until the
                    
STK LED
                lights up. Hold down the 
Mode button for at least 5 seconds, until all the front-panel port
                LEDs flash. The stack forms automatically, all the slots reboot, and 
ExtremeCloud
                    IQ detects the newly formed stack.

Note   
In 
Switch Engine or 
EXOS, if you are replacing a failed stack member with the same model
                    switch, the replacement slot is handled with the 
Replace Stack
                        Members action. On X440-G2 /5320/5420/5520 stacks, select the
                    stack, and select the 
Replace Stack Members action within 
Utilities. Select
                    the member, enter the serial number, and select 
Replace.
 
 
            
         
        
            Use this task to instantly configure a Switch Engine stack in ExtremeCloud IQ. 
            
        
        - 
                Go to .
            
 - 
                Find the new stack in the
                        Devices
                        List and select its check box.
            
 - 
                In the Template column, select Assign/Create
                        Template.
            
 - 
                Select the Create template based on currently selected
                        device.
            
 - 
                Select an existing stack
                    template from the drop-down list.
            
 - 
                Select Assign.
            
 
        
            The assigned template now displays in the Policy column. To
                make any changes to the individual devices in the stack at the device level, see
                    Configure Device-Specific Settings.