Administration: Stack Management
Unit ID Assignment
Cisco Sx350, SG350X, SG350XG, Sx550X & SG550XG Series Managed Switches, Firmware Release 2.2.5.x
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Topology Discovery
A stack is established by a process called topology discovery. This process is triggered by a
change in the up/down status of a stack port.
The following are examples of events that trigger this process:
•
Changing the stack topology from a ring to a chain
•
Merging two stacks into a single stack
•
Splitting the stack
•
Inserting other slave units to the stack, for instance because the units previously
disconnected from the stack due to a failure. This can happen in a chain topology if a
unit in the middle of the stack fails.
During topology discovery, each unit in a stack exchanges packets, which contain topology
information.
After the topology discovery process is completed, each unit contains the stack mapping
information of all units in the stack.
Unit ID Assignment
After topology discovery is completed, each unit in a stack is assigned a unique unit ID.
The unit ID is set in the
page in one of the following ways:
•
Automatically (Auto)
—The Unit ID is assigned by the topology discovery process.
•
Manually
—The unit ID is manually set to an integer from 1-maximum number of
units in a stack.
Duplicate Unit IDs
If you assign the same unit ID to two separate units, only one of them can join the stack with
that unit ID.
If auto numbering has been selected, the duplicate unit is assigned a new unit number. If auto
numbering was not selected, the duplicate unit is shut down.
