Understanding System Redundancy
If you configure two master-capable nodes in a SummitStack, one assumes the role of primary (also called "master") and the other assumes the role of backup.
The primary node provides all of the switch management functions including running the bridging and routing protocols, and configuring the switch. The primary node also synchronizes the backup node in case it needs to take over the management functions if the primary node fails.
For SummitStack, a node can be a redundant primary node if it has been configured to be master-capable.
To configure master capability on one or all nodes in a SummitStack, use one of the following commands:
configure stacking [node-address node-address | slot slot-number] alternate-ip-address [ipaddress netmask | ipNetmask] gateway configure stacking redundancy [none | minimal | maximal]