Cisco Linksys SFE2000 - Stack Unit Startup Process

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Chapter 3: Connecting the Switch
Understanding Advanced Stacking
Linksys One Ready Communications Solution
Chapter
3
become a Stack Master or a Backup Master if they are manually configured by the system
administrator or if they are reset to the factory default mode.)
Unit ID Allocation
Units are shipped from the factory without an assigned Unit ID, and must be assigned a
unique Unit ID before they can operate as part of a stack. Unit ID numbers are assigned to
units in one of two ways:
• Unit ID numbers are assigned by the system administrator, and can be changed only
manually by the system administrator.
• Unit ID numbers are allocated to a stack member unit by the Stack Master during
system initialization.
A unit that was assigned a Unit ID will usually keep this number even after it is rebooted. The
Stack Master may reallocate Unit IDs during system initialization to resolve duplicate Unit ID
conflicts (see below). Manually assigned Unit IDs cannot be changed by the Stack Master,
even if there is a conflict.
Unit ID assignment or change takes effect only during system initialization and does not take
place during system runtime. Units of a stack do not have to be numbered in sequence, and
can be interconnected as long as each unit has a unique ID and at least one unit of the stack
serves as Stack Master.
Stack Unit Startup Process
When a unit in stack mode is initialized (powered up or rebooted), it goes through the
following steps:
1. The Master Discovery and Master Election processes.
2. Unit ID allocation by the Stack Master (including duplicate Unit ID conflict resolution).
3. Unit and port configuration by the Stack Master.