Allied Telesis AT-x950-28XSQ, Installation Manual

Page: 59 / 190

AT-x950-28XSQ Switch and VCStack Installation Guide
59
Master and Member Switches
One switch of a stack functions as a master switch. Its main functions are
listed here:
 Coordinate and monitor stack operations.
 Verify that the switches are using the same version of
management software. It automatically downloads its management
software over the stacking cables to switches with different
software versions.

Verify that the switches have different ID numbers. It automatically
assigns new ID numbers to resolve conflicts where two or more
switches have the same ID number.
The other switch is called a member switch.
Selection of the
Master Switch
The switches of the stack designate the master switch during the
initialization process, when they are powered on or reset. They base the
selection of the master switch 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, the selection of the master
switch is 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 stack without adjusting the priority values, the master
switch is selected based on the MAC addresses if the units are powered
on simultaneously. If you power on the switches one at a time, the master
switch is the first switch powered on.