Alcatel-Lucent OmniSwitch 6850E Series Hardware User's Manual page 136

Roles Within the Stack
Using Saved Slot Information
The saved slot number is the slot number the switch will assume following a reboot. This information is
stored in a switch's boot.slot.cfg file; the switch reads its slot number assignment from this file at bootup
and assumes the specified slot number within the stack.
If switches in a stacked configuration have no preconfigured slot assignments, the slot number for each
switch is dynamically assigned by the system software. Slot numbers can also be manually assigned by the
user. For more information on manually assigning slot numbers, refer to
ment" on page 6-23.
When a stack with preconfigured slot information is booted, it is not the lowest MAC address that deter-
mines the primary management module. Instead, the slot information stored in each switch's boot.slot.cfg
is read by the system software and used in determining the primary. The switch with the lowest saved slot
number becomes the primary management module.
Note. Although, for ease-of-management purposes, it is recommended that slot numbers are assigned
beginning with slot number 1, it is not a requirement. In other words, a stack of four switches can have slot
assignments 3, 4, 5, and 6. However, it is important that each element in a stack is 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
For more information on using saved slot information to determine the primary switch in a stack, refer to
the diagram below:
Saved Slot 6
Saved Slot 5
Saved Slot 4
Saved Slot 3
Reload
Assumes Slot 6
Assumes Slot 5
Assumes Slot 4
Assumes Slot 3
Slot 6
Slot 5
Slot 4
Primary: Slot 3
Primary Management Module Selection Using Saved Slot Information
page 6-8
Managing OmniSwitch 6850E Series Stacks
1
Four switches are stacked; all switches are connected via stack-
ing cables. The user configures each switch to have a unique
saved slot number. When each saved slot number is configured,
the information is automatically
written to the boot.slot.cfg file located in the /flash directory of
each switch.
2
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.
3 Instead of assigning the primary management module
based on the lowest MAC address, 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.
4
The switch with the lowest assigned slot number automatically
assumes the primary management role. In this case, the switch
assigned slot 3 has the lowest slot number in the stack and
becomes the primary management module.
OmniSwitch 6850E Series Hardware Users Guide
"Manual Slot Number Assign-
page 6-13.
January 2013