•
The daisy chain topology is mainly used in a network where member devices are
distributively located.
•
The ring topology is more reliable than the daisy chain topology. In a daisy chained
stack, link failure can cause stack split. While in a ring connected stack, the system is
able to operate normally with a new daisy chained topology.
Note:
Establish a stack of ring or daisy chain topology with eight T3700G-28TQ/T3700G-52TQ
switches at most.
2
）
Topology Collection
Each member in the stack collects the topology of the whole stack by exchanging stack
discovery packets with its neighbors. Discovery packet carries topology information
including stack port connection status, unit number, priorities, MAC addresses, etc.
Each member keeps a local record of the known topology information. When the device
initializes, it only possesses the record of its own topology information. Periodically the
stack members send out their known topology information through the stack ports to its
neighbors. When the neighbors receive the information, they will update their local
topology information. After a period of time of broadcasting and updating information, all
the stack members can collect the complete topology information (known as topology
convergence).
Then the switch enters the master election stage.
3
）
Master Election
After all members have obtained topology information (known as topology convergence),
the stack enters the master election stage. A stack always has one stack master, while the
other stack members are members. Master election determines the stack role of the stack
members.
Master election is held each time the topology changes, for example, when stack merge or
split occurs, or the stack or the current master is reset.
The master is elected based on the following rules and in the order listed:
1.
The switch that is currently the stack master.
2.
The switch with the highest stack member priority value.
3.
The switch with the lowest MAC address.
After master election, the stack forms and enters into stack management and
maintenance stage.
Note:
1.
The priority value ranges from 1 to 15. The higher the value is, the more likely the
member will be elected as the master. By default, the member priority of the switch is 5.
We recommend you manually assign the highest priority value to the switch that you
prefer to be the stack master before stack establishment.
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