D-Link DGS-3324SR Product Manual - Page 35

xStack DGS/DXS-3300 Series Layer 3 Stackable Gigabit Ethernet Switch User Manual Stacking Limitations Utilizing a Ring or Star Topology The switches listed in the table below can all be stacked, but there is a limitation as to the number of Switches that can be included in a given stack. This limitation arises from a concept called a Token Cost. This Token Cost is used for communication between switches in a switch stack. Some of the switches have 2 as their token cost, while others are 4, and the 10G uplink ports have a Token Cost of 2. The maximum accumulated Token Cost in a given stack must be less than or equal to 32. There is an additional limitation in that a maximum of 12 Switch boxes can be included in a given switch stack, using a ring topology. The DGS-3324SRi cannot be used in a ring topology. For the Star topology, the maximum number of switches in the stack is seven {6 slaves + 1 master (DGS-3324SRi)} In order to make the task of determining if a given set of Switches (from the table below) can be successfully stacked, use the following formula: Token Cost * Number of Switches ≤ 32 Model Name Token Cost DGS-3324SRi 2 DGS-3324SR 2 DXS-3350SR 4 6 (with 10G uplink) DXS-3326GSR 2 4 (with 10G uplink) Table 3- 1. Switches and their corresponding token cost Stacking In a Ring Topology For example: All of the stacked switches are identical. To stack as many DGS-3324SR switches as possible. To calculate the maximum number of DGS-3324SR switches in the ring stack, use the following formula: Token Cost * Number of Switches ≤ 32 2 * Number of Switches ≤ 32 Number of Switches ≤ 32/2 Number of Switches ≤ 16 For this example, a maximum of sixteen DGS-3324SR switches can be ring stacked according to the previous calculations, but we must remember that there is a maximum limitation of twelve switches, so the actual maximum number of DGS3324SR switches that can be stacked together in the ring topology is twelve. 20