Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.112.1P1 - Page 883
Influencing Management Unit Selection on a Stack, Managing Redundancy on a Stack
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1/60 3/60 40 up up 3/48 40 up down 3/52 40 up down 3/56 0/56 40 up up 3/60 0/60 40 up up Influencing Management Unit Selection on a Stack Stack priority is the system variable that Dell Networking OS uses to determine which units in the stack are the master and standby management units. If multiple units tie for highest priority, the unit with the highest MAC address prevails. If management was determined by priority only, a change in management occurs when: • the management unit is powered down or a failover occurs. • you disconnect the management unit from the stack. When the management unit fails, the unit disappears from the stack topology. At that time, the standby unit detects the communication loss and switches from the standby unit role to the management unit role in the stack. From the remaining units in the stack, the system selects a new standby unit based on the unit priority using the same algorithm used when the stack was initially created. When the failed unit recovers, it takes the next available role, usually that of a stack member. • Influence the selection of the stack management units. CONFIGURATION mode stack-unit unit-number priority priority-value The unit with the numerically highest priority is elected the master management unit, and the unit with the second highest priority is the standby unit. The range is from 1 to 14. The default is 0. Managing Redundancy on a Stack Use the following commands to manage the redundancy on a stack. • Reset the current management unit and make the standby unit the new master unit. EXEC Privilege mode redundancy force-failover stack-unit A new standby is elected. When the former stack master comes back online, it becomes a member unit. • Prevent the stack master from rebooting after a failover. CONFIGURATION mode redundancy disable-auto-reboot stack-unit This command does not affect a forced failover, manual reset, or a stack-link disconnect. • Display redundancy information. EXEC Privilege mode show redundancy Stacking 883
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