Dell POWEREDGE M1000E - Manual (Page 139)

Managing a Switch Stack 139
PowerConnect 7000 Series and M6348 Stacking Compatibility
The stack can contain any combination of switch models in the
PowerConnect 7000 Series as well as the PowerConnect M6348 switch, as
long as all switches are running the same firmware version.
For example, a single stack of six switches might include the following
members:
• Two PC7048 switches
• One PC7024 switch
• Three PCM6348 switches
Any member can be the stack Management Unit.
How is the Management Unit Selected?
A stack manager is elected or re-elected based on the following
considerations, in order:
1 The switch is currently the stack manager.
2 The switch has the higher MAC address.
In most cases, a switch that is added to an existing stack will become a stack
member, and not the Management Unit. When you add a switch to the stack,
one of the following scenarios takes place regarding the management status of
the new switch:
• If the switch has the Management Unit function enabled but another
Master unit is already active, then the switch changes its configured
Management Unit value to disabled.
• If the Management Unit function is unassigned and there is another
Management Unit in the system then the switch changes its configured
Management Unit value to disabled.
• If the Management Unit function is enabled or unassigned and there is no
other Management Unit in the system, then the switch becomes
Management Unit.
NOTE: The terms "Master" and "Manager/Management Unit" are often used
interchangeably through out this chapter.