Dell Force10 S55T S55 Configuration Guide FTOS 8.3.5.3 - Page 723

The S50 and S25 systems support mixed stacking, as long as the units have the same FTOS version. The S55 and S60 systems DO NOT SUPPORT mixed stacking. Stack only S55 systems together or only S60 systems together; do not stack them with any other system type. Figure 40-8 shows two common stacking topologies, ring and cascade (also called daisy-chain). A ring topology provides some performance gains and stack integrity. Note: The illustration below is an example to show ring and cascade topologies. Please refer to the Installation document for your system type to view a diagram for the topology supported by your system. Figure 40-8. Common S-Series Stacking Topologies (S50-type) Ring Connection Cascade Connection A B A B A B A B A B A B A B Facing the rear of an S-Series unit, stack-port are numbered from left to right, beginning with the highest Ethernet port number (n) plus 1. For example, for a 48-port unit with two 12-Gigabyte stacking modules, the stack-ports are 49, 50, 51, and 52. Note: The S55 stacking modules are installed in the lower optional module slot (slot 0) and use ports 48 and 49. To add a unit to an existing stack: Step 1 2 3 4 Task Verify that each unit has the same FTOS version prior to stacking them together. Pre-configure unit numbers for each unit so that the stacking is deterministic upon boot up. Configure the switch priority for each unit to make management unit selection deterministic. Connect the units using stacking cables. Command Syntax show version stack-unit renumber stack-unit priority Command Mode EXEC Privilege EXEC Privilege CONFIGURATION Stacking S-Series Switches | 723