Managing OmniSwitch 6450 Stacks Reloading Switches
OmniSwitch 6450 Hardware Users Guide September 2015 page 7-33
No Switches In the Stack Have Saved Slot Information
If a full reload is issued and no switches in the stack have unique slot numbers, slot numbers will be 
assigned beginning with the switch with the lowest MAC address. (This can occur if the boot.slot.cfg file 
has been deleted from each switch’s /flash directory—e.g., by issuing the stack clear slot command for all 
modules in the stack.) 
The switch with the lowest MAC address is assigned slot number 1 and given the primary management 
role. The switch connected to stacking port A of the primary switch is automatically assigned slot 
number 2 and given the secondary management role. Stack cabling is then used to determine the dynamic 
slot numbering of the remaining modules in the stack. The switch immediately adjacent to slot 2 is 
assigned slot number 3 and given an idle role, etc.
An illustrated example of this method for assigning slot numbers and management roles is provided on 
pages 7-21 and 7-22.
Some Switches Have Saved Slot Information, Others Do Not
If only some switches in the stack have boot.slot.cfg files in their /flash directories, the system software 
will first read the contents of these files and then dynamically assigns unique slot numbers to any switches 
that do not have saved slot information. The primary management role will be given to the switch with the 
lowest saved slot number. The secondary management role will be given to the switch with the second-
lowest saved slot number. All other switches will be assigned to idle roles.
When unique slot numbers are dynamically assigned by the system software, a boot.slot.cfg file is auto-
matically generated with the new slot information. Because all switches now have unique saved slot infor-
mation, any subsequent reload all commands issued will cause the stack to come up as described in the 
section, “All Switches Have Unique Saved Slot Information” on page 7-32.
Two or More Switches Have Duplicate Slot Information
If a full stack reboot is issued and the same slot number is found in the boot.slot.cfg file of two or more 
switches, the switch with the lowest MAC address is allowed to come up and operate normally. Mean-
while, any other switches with the duplicate slot number come up in pass-through mode. 
The pass-through mode is essentially an error state in which a switch has been denied primary, secondary, 
and idle roles within the stack. When a switch is in pass-through mode, its Ethernet are brought down and 
cannot pass traffic. It is for this reason that users should always check the current saved slot number for 
each switch before issuing the reload all command. To check the current saved slot information across the 
stack, use the show stack topology command. For detailed information on pass-through mode, refer to 
“Pass-Through Mode” on page 7-13.