Alcatel OS6850-P48 User Guide - Page 186

Slot Numbering Managing OmniSwitch 6850/6850E Series Stacks If the switch with the lowest MAC address happens to be the bottom-most module in the stack, slot numbering will not resume from the top of the stack. Instead, the system software will select the secondary module using the standard method (i.e., the switch connected to the primary's stacking port A), then continue to number the stack from the bottom up. This intuitive slot assignment provides the cleanest and most manageable stack topology. Refer to the diagram below for more information: Slot 8 - Idle Slot 7 - Idle Slot 6 - Idle Slot 5 - Idle Slot 4 - Idle Slot 3 - Idle Slot 2 - Secondary Slot 1 - Primary In this example, the bottom switch 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 above 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 then sequentially assigns slot numbers up the stack. In other words, the switch immediately above slot 2 is assigned the slot number 3; the switch immediately above slot 3 is assigned the slot number 4, and so on. This default procedure ensures the most ordered and manageable stack topology out of the box. Dynamic Slot Numbering Example 2 page 6-24 OmniSwitch 6850/6850E Series Hardware Users Guide June 2011