Default mastership determination:
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Member with highest user configured priority (1-155), default is 128.
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Member previously functioning as master prior to reboot
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Member with the longest standing time (difference must be greater than 1 minute)
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Member with the lowest MAC Address (used as a tie breaker if all is equal through the first three determination steps)
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Second member in election decision tree becomes backup switch; all other members are linecards
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Note: If a master or backup fails, one of the linecards is elected the new backup switch using same criteria
Below you will find a brief description of best practice priority configuration:
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Specify the same mastership priority value for the master and backup switches in a Virtual Chassis configuration. Doing so helps to ensure a smooth transition from master to backup if the master switch becomes unavailable. This configuration also prevents the original master switch from retaking control from the backup switch when the original master switch comes back online, a situation sometimes referred to as flapping or pre-emption that can reduce the efficiency of system operation.
- Configure the highest possible mastership priority value (255) for the master and backup switches. This configuration ensures that these members continue to function as the master and backup switches when new members are added to the Virtual Chassis configuration.
Use the following command to setup mastership priority:
# set virtual-chassis member <member-id> mastership-priority <priority value>
