Stacking Limitations Utilizing A Ring Or Star Topology - D-Link xStack DGS-3324SRi User Manual

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:
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:
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 DGS-
3324SR switches that can be stacked together in the ring topology is twelve.
Token Cost * Number of Switches ≤ 32
Model Name
DGS-3324SRi
DGS-3324SR
DXS-3350SR
DXS-3326GSR
Table 3- 1. Switches and their corresponding token cost
Token Cost * Number of Switches ≤ 32
2 * Number of Switches ≤ 32
Number of Switches ≤ 32/2
Number of Switches ≤ 16
Token Cost
2
2
4
6 (with 10G uplink)
2
4 (with 10G uplink)
20