D-Link DMS-3130 User Manual - Page 97

DMS-3130 Series Multi-Gigabit L3 Stackable Managed Switch Web UI Reference Guide Figure 4-69 Duplex Ring stacking topology (SFP28 ports) NOTE: For more stacking topologies, please refer to Switch Stacking section in DMS-3130-Series HW Installation Guide. Switch Roles in a Stack Within each of these topologies, each Switch plays a role in the Switch stack. These roles can be set by the user per individual Switch, or if desired, can be automatically determined by the Switch stack. Three possible roles exist when stacking with the Switch. Primary Master - The Primary Master is the leader of the stack. It will maintain normal operations, monitor operations and the running topology of the Stack. This Switch will also assign Stack Unit IDs, synchronize configurations and transmit commands to remaining Switches in the Switch stack. The Primary Master can be manually set by assigning this Switch the highest priority (a lower number denotes a higher priority) before physically assembling the stack, or it can be determined automatically by the stack through an election process. This determines the lowest MAC address and then will assign that Switch as the Primary Master if all priorities are the same. The Primary master is physically displayed by the seven segment LED to the far right on the front panel of the Switch where the LED will flash between its given Box ID and 'H'. Backup Master - The Backup Master is the backup to the Primary Master and will take over the functions of the Primary Master if the Primary Master fails or is removed from the Stack. It also monitors the status of neighboring Switches in the stack, will perform commands assigned to it by the Primary Master and will monitor the running status of the Primary Master. The Backup Master can be set by the user by assigning this Switch the second highest priority (a lower number denotes a higher priority) before physically assembling the stack, or it can be determined 86