Master Selection Process - Cisco SF500-24 Administration Manual

Stack Management

Master Selection Process

Master Selection Process
NOTE
Cisco 500 Series Stackable Managed Switch Administration Guide
The master unit is selected from among the master-enabled units (1 or 2). The
following are taken into account in the following priority:
• Force Master - If force master is activated on a unit, it is selected. If a unit is
forced, it remains forced even after reboot.
• System Up Time -The master-enabled units exchange up time, which is
measured in segments of 10 minutes. The unit with the higher number of
segments is selected as the master. Note: The up time of the backup unit is
retained when it is selected as master in the switch failover process.
• Unit ID - If both units have the same number of time segments, the unit with
the lowest unit ID is selected.
• MAC Address - If both units IDs are the same, the unit with the lowest MAC
address is chosen.
For a stack to operate, it must have a master unit. A master unit is defined as the
active unit that assumes the master role. The stack must contain a unit 1 and/or unit
2 after the master selection process. Otherwise, the stack and all its units are
partially shut down, not as a complete power-off, but in a condition where the LEDs
are still on, but traffic-passing capabilities are halted.
5
59