Chapter 3: Stacking

manually configured as the Stacking Master, the manually configured member is elected Stacking Master.

If two Master-enabled units are present and neither has been manually configured as the Stacking Master, the one with the longer up-time is elected Stacking Master.

If the two Master-enabled stacking members are the same age, Unit 1 is elected Stacking Master.

Two stacking member are considered the same age if they were inserted within the same ten minute interval.

For example, if Stack member 2 is inserted in the first minute of a ten- minute cycle, and Stack member 1 is inserted in fifth minute of the same cycle, the units are considered the same age. If there are two Master- enabled units that are the same age, then Unit 1 is elected Stacking Master.

The Stacking Master and the Secondary Master maintain a Warm Standby. The Warm Standby ensures that the Secondary Master takes over for the Stacking Master if a failover occurs. This guarantees that the stack continues to operate normally.

During the Warm Standby, the Master and the Secondary Master are synchronized with the static configuration only. When the Stacking Master is configured, the Stacking Master must synchronize the Secondary Master. The Dynamic configuration is not saved, for example, dynamically learned MAC addresses are not saved.

Each port in the stack has a specific Unit ID, port type, and port number, which are part of both the configuration commands and the configuration files. Configuration files are managed only from the device Stacking Master, including:

ˆSaving to the Flash

ˆUploading configuration files to an external TFTP Server

ˆDownloading configuration files from an external TFTP Server

Whenever a reboot occurs, topology discovery is performed, and the Master learns all units in the stack. Unit IDs are saved in the unit and are learned through topology discovery. If a unit attempts to boot without a selected Master, and the unit is not operating in stand-alone mode, the unit does not boot.

Configuration files are changed only through explicit user configuration.

Configuration files are not automatically modified when:

ˆUnits are added

ˆUnits are removed

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Allied Telesis AT-8000GS/24, AT-8000GS/POE manual Stacking