Alcatel-Lucent OMNISWITCH 6800 - Manual (Page 98)

Slot Numbering Managing OmniSwitch 6800 Series Stacks
page 3-18 OmniSwitch 6800 Series Hardware Users Guide June 2007
Slot Numbering
For a stack of OmniSwitch 6800 Series switches to operate as a virtual chassis, each module in the stack
must be assigned a unique slot number. To view the current slot assignments for a stack, use the
show ni
or show module commands. The slot number is also displayed on the front panel of each switch by the
LED located on the right side of the chassis (refer to “Status LEDs” on page 2-13 for more information).
There are two ways stacking modules are assigned slot numbers:
• Dynamic slot number assignment by the system software
• Manual slot number assignment by the user
Dynamic Slot Number Assignment
Dynamic slot number assignment occurs when there are no boot.slot.cfg files present in the switches’
/flash directories. This is the case for new, “out of the box,” switches that have not been previously booted.
When a brand new stack (or stack with no boot.slot.cfg files) is booted, the system software automatically
detects the module with the lowest MAC address. This module is assigned the primary management role
(see
page 3-2 ) and, by default, is given the slot number 1. The module connected to the primary’s stacking
port A is automatically assigned the secondary management role and given the slot number 2.
As the other modules in the stack become operational, they are assigned idle roles and are automatically
assigned unique slot numbers (3–8, depending on the number of switches in the stack). The slot number-
ing for idle modules is determined by each module’s physical location in the stack. Refer to the diagrams
below for more information on dynamic slot numbering.
Note. As the slot numbers are dynamically assigned, boot.slot.cfg files are auto-generated in the /flash
directory of each switch. When modules are subsequently booted, each switch reads its slot number
assignment from this file and comes up accordingly.
Dynamic Slot Numbering Example 1
Slot 1 - Primary
Slot 2 - Secondary
Slot 3 - Idle
In this example, the fourth switch from the top is
elected the primary management module for the
stack. (It can be assumed that this switch has the
lowest MAC address in the stack.) This switch is
automatically assigned slot number 1.
The switch immediately below is connected to the
primary switch’s stacking port A and, as a result, is
assigned the secondary management role and given
slot number 2.
The system software allows the switch immediately
below slot 2 to have the next slot number preference.
It is assigned an idle role and given the slot number 3.
The switch immediately below slot 3 is given the slot
number 4, and so on. When the bottom of the stack is
reached, the slot numbering sequence resumes at the
top of the stack, as shown. This helps ensure a more
ordered and manageable stack topology.
Slot 4 - Idle
Slot 5 - Idle
Slot 6 - Idle
Slot 7 - Idle
Slot 8 - Idle