Alcatel-Lucent 6850-48 Hardware Manual

Page of 188
Roles Within the Stack
Managing OmniSwitch 6850 Series Stacks
page 4-10
OmniSwitch 6850 Series Hardware Users Guide
September 2009
Using Saved Slot Information
If a stack with preassigned slot information for each switch is booted, the switch with the second lowest 
slot value is assigned the secondary management role. For example, if a stack of four switches is booted 
and the preassigned slot values for each switch are 1, 2, 3, and 4, the switch with the slot value of 2 is 
assigned the secondary role. Meanwhile, the switch with the slot value of 1 is assigned the primary 
management role (see 
For more information on using saved slot information to determine the secondary management module in 
a stack, refer to the diagram below:
Secondary Management Module Selection Using Saved Slot Information
Reminder. Each element in a stack should always be assigned a unique slot number. Do not assign 
duplicate slot numbers to elements in a stack. Otherwise, one or more switches will be forced into 
pass-through mode. For more information on pass-through mode, refer to 
Primary - Slot 1
Slot 3
Slot 4
Secondary - Slot 2
Assumes Slot 1
Assumes Slot 3
Assumes Slot 4
Assumes Slot 2
Saved Slot 1
Four OmniSwitch 6850 Series switches are stacked; all switches 
are connected via stacking cables. The user configures each 
switch to have a unique saved slot number, as shown. When the 
saved slot number is configured, the information is automatically 
written to the boot.slot.cfg file located in the /flash directory of 
each switch. 
The user reloads all the elements in the stack either by issuing 
the reload all command or by physically powering off and then 
powering on all switches.
The system software reads the slot information from each 
switch’s boot.slot.cfg file during the boot process. The switches 
in the stack come up using their assigned slot numbers.
The switch with the lowest assigned slot number automatically 
assumes the primary management role. The switch with the 
second lowest assigned slot number becomes the secondary 
management role, regardless of whether it is attached to stacking 
port A of the primary switch. In this case, the switch assigned 
slot 2 has the second-lowest slot number in the stack and becomes 
the secondary management module.
1
2
3
4
Saved Slot 3
Saved Slot 4
Saved Slot 2
Reload