D-Link DXS-3400 SERIES Web Ui Reference Manual page 93

DXS-3400 Series Lite Layer 3 Stackable 10GbE Managed Switch Web UI Reference Guide
The figure below illustrates how Switches can be stacked in a Duplex Ring formation using optical fiber cables
connected to SFP+ transceivers or Direct Attached Cables (DAC) with SFP+ connectors where the 2-port stacking
configuration is used.
NOTE: SIO1 is a logical stacking port pair. SIO2 is also a logical stacking port pair. A logical stacking
port pair must always be connected to the same Switch in the stack. Splitting logical stacking
port pairs between different Switches in the stack might not guarantee a stable stacking
connection.
Within each of these topologies, each Switch plays a role in the Switch stack. These roles can be set by the user per
individual Switch, or if desired, can be automatically determined by the Switch stack. Three possible roles exist when
stacking with the Switch.
Primary Master - The Primary Master is the leader of the stack. It will maintain normal operations, monitor operations
and the running topology of the Stack. The Switch will also assign Stack Unit IDs, synchronize configurations and
transmit commands to remaining Switches in the Switch stack. The Primary Master can be manually set by assigning
Figure 4-77 Duplex Ring stacking topology (RJ45)
Figure 4-78 Duplex Ring stacking topology (SFP+)
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