Alcatel OS6850-P48 User Guide - Page 181

Managing OmniSwitch 6850/6850E Series Stacks Stack Cabling Note. When planning the stack cabling configuration, keep in mind that the switch connected to stacking port A of the primary switch will be assigned the secondary management role by default. A B A stack of eight switches in a crossed (stacking port A to stacking port B) configuration. Note that a redundant stacking cable connection exists between the top and bottom switches. This connection is required for effective redundancy across the stack. A B A stack of eight switches in a straight (stacking port A to stacking port A; stacking port B to stacking port B) configuration. Note that a redundant stacking cable connection exists between the top and bottom switches. Again, this connection is required for effective redundancy across the stack. Examples of Stacking Cable Patterns (Chassis Rear Panels Shown) Redundant Stacking Cable Connection OmniSwitches allow redundant stacking cable connections between the top-most and bottom-most switches in a stack. Important. For a stacked configuration to have effective redundancy, a redundant stacking cable must be installed between the upper-most and bottom-most switch in the chassis at all times. OmniSwitch 6850/6850E Series Hardware Users Guide June 2011 page 6-19