Stack Management
Unit ID Assignment
Cisco 500 Series Stackable Managed Switch Administration Guide
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5
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
System Mode and Stack Management
page in one of the
following ways:
•
Automatically (Auto)
—Unit ID is assigned by the topology discovery
process. This is the default setting.
•
Manually
—By manually setting the unit ID.
Duplicate Unit IDs
If the user assigns 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.
The following are examples of unit ID duplication that might occur.
Figure 4
shows a case where two units received the same unit ID, manually. The
second unit 1 was subsequently shut down.
Figure 4 Duplicate Unit Shut Down
In the figure above, Unit 1 does not join the stack and is shut down. It did not win
the master selection process between the master-enabled units (1 or 2).
