Dell Force10 S25N-S50N Installing S25N and S25V Systems - Page 27

Connecting Stack Ports (optional) The switch contains two expansion slots in the rear, in either of which you can insert stacking modules for converting the switch into a virtual slot in a single virtual switch, called a stack (they all must be running the same software version). The switch provides two optional choices in stacking modules - a single-port 24G module and a two-port 12G module. You cannot interconnect the two types of module. If you use 24G modules, you can insert one in each of the two expansion slots to accomplish the ring topology (Figure 13). You can connect the switches while they are powered down or up. You can use either a ring topology or cascade topology connection (see Figure 12). Use the special stacking cables to connect them. Force10 recommends that you mount the switches before you make your stack port connections. Figure 12 Switch Stacking Topologies (showing dual-port modules) Ring Topology Switch 1 A B Cascade Topology Switch 1 A B Switch 2 A B Switch 2 A B Switch 3 A B Switch 3 A B While the diagram, above, shows A-B port connections, the ports are bi-directional, so you can connect A to A and/or B to B, as shown below in examples of two-switch (Figure 14 on page 28) and three-switch (Figure 15 on page 28) ring topologies. Figure 13 shows the use of 24G stack ports in each of the two rear modules to create a ring. Of course, this topology does not allow the use of any rear modules for XFP ports. A cascade topology, removing the stack port modules in the B slots of switches 1 and 2, would free those slots for use by XFP modules. Figure 13 Stacking Topology Using 24G Single-port Modules Module A Switch 1 A A Switch 2 Module B B B Ring topology using two 24GbE modules per unit Switch 3 A B Installing S25N and S25V Systems 27