A stack is a collection of switches in which one switch controls the operation of all switches. This controlling switch is called the stack manager. The remaining switches in the stack are called stack members. The stack manager and members use stacking technology to function as a unified system. The switch stack is presented to the network as a single entity. The stack manager is the single point of management for the stack.
The network IP address of a stack enables the network to identify the stack. The network IP address is assigned according to the MAC address of the stack manager. Every stack member is uniquely identified by its own stack member number.
All stack members are eligible stack managers. If the stack manager becomes unavailable, the remaining stack members participate in electing a new stack manager among themselves.
The following rules determine which switch is elected as the stack manager:
- The switch that is the stack manager always has priority to retain the role of manager.
- If none of the member switches previously functioned as the stack manager, the member switch with the highest priority is elected as the stack manager. You can configure the priority of a switch through the web manager interface.
- If all switches have the same priority, the switch with the largest MAC address is elected as the stack manager.
All stack members must run the same software version to ensure compatibility between them. If a prospective stack member is running a software version that is not the same as the stack manager, the stack manager does not allow the prospective stack member to join the stack.
The following series of smart switches support stacking:
- Stackable Smart Switches: GS728TS, GS728TPS, GS752TS, and GS752TPS running software release 5.3.0 or later.
- Stackable Smart Switches with 10G Uplinks: GS728TXS and GS752TXS running software release 6.1.0 or later.
In a stack, you can mix and match different switch models from the same switch series. However, you cannot mix switch models from different switch series.
The following stacking functionalities are supported in software release 5.3.0 and 6.1.0:
- Basic functionality for stacking
- Support for up to six switches in a stack.
- Stack management over a single IP address through the web management interface and Smart Control Center.
- Manager-member configuration.
- Configuration for all units is stored on the manager.
- Auto detection for new members, with synchronization of firmware (that is, firmware upgrade or downgrade as needed).
- Download of configuration updates across the stack through a single operation.
- Automatic master failover in a fully resilient stack with either a chain or ring topology.
- Hot swappable stack units.
- Stack number information and automatic stacking setup.
- Factory default reset behavior
The stack manager initializes the stack using the last saved system configuration that is stored on its flash memory. If you reset the stack manager to factory default settings, the stack manager applies the default settings to all the stack members.