graceful_shutdown parameter is sent to all the spine‘s
					underlay neighbors (all leafs in the pod and super-spines). The neighbors no
					longer send traffic to the first spine going into maintenance mode and redirect
					traffic to an alternate path. 
			running-configuration is saved on the first spine to
					preserve all current configurations including the maintenance mode enable
					configuration. 
			running-config is saved again to ensure the maintenance
					mode config remains disabled. 
				The same process can be carried out on the second spine to upgrade the firmware without traffic loss.



