Figure 3-7shows how the stack cables are connected between switches in a stack. Each stacking connection is a 40 Gbps full-duplexhigh-speed serial link using proprietary stacking cables. The switch supports a line- and ring-topology stacking configuration, or can be used stand alone.
In line-topology stacking there is a single stack cable connection between each switch that carries two-way communications across the stack. In ring-topology stacking, an extra cable is connected between the top and bottom switches forming a “ring” or “closed-loop.” The closed-loop cable provides a redundant path for the stack link, so if one link fails, stack communications can be maintained. Figure 3-7illustrates a ring-topology stacking configuration.
To connect up to eight switches in a stack, perform the following steps:
1.Plug one end of the stack cable (ordered separately) in the Down (right) port of the top unit.
2.Plug the other end of the stack cable into the Up (left) port of the next unit.
3.Repeat steps 1 and 2 for each unit in the stack. Form a simple chain starting at the Down port on the top unit and ending at the Up port on the bottom unit (stacking up to 8 units).
