Master And Member Switches; Selection Of The Master Switch - Allied Telesis AlliedWare Plus Installation Manual

Master and Member Switches

Selection of the
Master Switch
Stacks have a master switch. Some of its functions include:
Coordinate and monitor stack operations.

Verify that the switches are using the same version of

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 that connect the switches

together are cabled correctly.
The other switches are called member switches. A member switch can
automatically transition to the master role if the current master switch is
removed from the stack or powered off. This ensures continued operations
of the stack even if the master switch stops operating.
The switches of the stack designate the master switch during the
initialization process that they perform whenever they are powered on or
reset. They select the master switch based on the following parameters:
Stack priority numbers

MAC addresses

The stack priority number is an adjustable value of 0 to 255, where the
lower the number, the higher the priority. Typically, the switch with the
lowest priority number (highest priority) becomes the master switch of a
stack. The default priority value is 128.
If the switches have the same priority values, they select the master switch
based on their MAC addresses. As with the priority value, the lower the
MAC address, the higher the priority. The switch with the lowest MAC
address becomes the master switch.
If you power on the switches of the stack simultaneously without adjusting
the priority values, they select the master switch based on their MAC
addresses. If you power on the switches one at a time, the master switch
is the first switch to be powered on.
After the stack is established and operating, you may change the priority
settings on the individual units and so control which switch will be the
master switch the next time you reboot or power on the stack.
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