Dell POWEREDGE M1000E - Manual (Page 136)

136 Managing a Switch Stack
becomes the Master if the Master unit is unavailable. You can manually
configure which unit is selected as the standby, or the system can select the
standby automatically.
When units are in a stack, the following activities occur:
• All units are checked for software version consistency.
• The switch Control Plane is active only on the Master. The Control Plane
is a software layer that manages system and hardware configuration and
runs the network control protocols to set system configuration and state.
• The switch Data Plane is active on all units in the stack, including the
Master. The Data Plane is the set of hardware components that forward
data packets without intervention from a control CPU.
• The running configuration and application state is synchronized between
the Master and Standby during the normal stacking operation.
In a stack of three or more switches, Dell strongly recommends connecting
the stack in a ring topology so that each switch is connected to two other
switches.
Creating a PowerConnect M6220 Stack
You can stack up to 12 PowerConnect M6220 units, supporting up to 240
1-Gb ports. Create a stack by connecting adjacent units using the stacking
ports on the top of the switch panel.
1 Install a separately purchased stacking module in Bay 1 of each of the
switches in the stack.
2 For each switch in the stack, connect one of the short stacking cables from
stacking port one on the switch to stacking port two on the next switch.
3 If necessary, use a separately purchased, long (3 meter) stacking cable to
connect the switches. Repeat this process until all of the devices are
connected.
4 Use the remaining stacking cable to connect the remaining free ports, from
port one of the last switch to port two of the first switch.