Master And Member Switches; Selection Of The Master Switch - Allied Telesis AT-x550-18XTQ Installation Manual

Master and Member Switches

Selection of the
Master Switch
A stack has one master switch. The other switches are member switches.
The main functions of the master switch are listed here:
 Coordinate and monitor stack operations.
 Configure the parameter settings of the switches using its
configuration file in flash memory, whenever the stack is reset or
powered on.
 Verify that the switches are using the same version of
management software. It automatically downloads its management
software to the member switch over the stacking cables if the
member switch has a different version of the management
software.
 Verify that the switches have different ID numbers. It automatically
assigns new ID numbers to resolve situations where two or more
switches have the same ID number.
 Verify that the stacking transceivers are from Allied Telesis and
they are cabled correctly.
The parameter settings of the switches of the stack are stored in
configuration files in the flash memories of the master and member
switches. Each file contains all the settings for the switches in the stack.
The switches update the files with the latest parameter settings whenever
you issue the WRITE command to save your changes.
When you reset or power on the stack, the master switch uses the
configuration file in its flash memory to restore its own parameter settings
as well as the parameter settings of the member switches in the stack. A
member switch uses its configuration file to restore parameter settings
only if the master switch is removed or fails, and it becomes the new
master switch of the stack.
The switches of a stack select the master switch during the initialization
process, which they perform whenever they are powered on or reset. The
master switch is selected using the following parameters:
 Stack priority numbers
 MAC addresses
The stack priority number is an adjustable value of 0 to 255. The lower the
number, the higher the priority. The switch with the lowest priority number
(highest priority) becomes the master switch of a stack. The default priority
value is 128.
When switches have the same priority values, they compare their MAC
addresses to select the master switch. As with the priority value, the lower
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