Dell PowerEdge FX2/FX2s - Manual (Page 189)

2. The switch with the highest MAC address at boot time.
3. A unit is selected as Standby by the administrator, and a fail over action is manually initiated or
occurs due to a Master unit failure.
No record of previous stack mastership is kept when a stack loses power. As it reboots, the election
process will once again determine the Master and Standby switches. As long as the priority has not
changed on any members, the stack will retain the same Master and Standby.
NOTE: Each stack members’ role (including the Master and Standby) can be defined by the user at
any time by setting the priority.
If the entire stack is powered OFF and ON again, the unit that was the Master before the reboot will
remain the Master after the stack resumes operation. However, when a stack is powered on, all members
are in sleep mode for 5 seconds while waiting on the previous Master to join the stack. If the previous
Master fails to join within 5 seconds, the remaining members (including the Standby) elect a new Master.
Configuring Priority and stack-group
Perform the following steps to configure the priorities and stack-groups for each of the switches.
1. Set the priorities for the stack-unit.
CONFIGURATION mode
stack-unit unit-number priority 1-14
Dell(conf)# stack-unit 0 priority 12
Setting the priority will determine which switch will become the management (Master) switch. The
switch with the highest priority number is elected Master. The default priority is 0.
NOTE: It is best practice to assign priority values to all switches before stacking them in order
to acquire and retain complete control over each units role in the stack.
2. Configure the stack-group for each stack-unit.
CONFIGURATION mode
stack-unit unit-no stack-group stack-group-id
Dell(conf)# stack-unit 0 stack-group 0
Dell (conf)#02:26:05: %STKUNIT0-M:CP %IFMGR-6-STACK_PORTS_ADDED:
Ports Fo 0/33 have been configured as stacking ports.
Please save and reload for config to take effect
Stack-groups are easier to think of simply as stack ports. For example, using the stack-group 0
command simply turns the lower port (port 9) into a stacking port. Similarly, stack-group 1,
stack-group 2 and stack-group 3 commands correspond to ports 10, 11 and 12 respectively.
NOTE: Stack-group is supported only in PMUX mode.
3. Continue to run the stack-unit 0 stack-group <0-3> command to add additional stack ports
to the switch, using the stack-group mapping.
Stacking 189