Allied Telesis CentreCOM GS970EMX/52 Installation Manual page 61

CentreCOM GS970EMX Series Installation Guide for Virtual Chassis Stacking
Table 9. Stacking Worksheet Columns (Continued)
Column
Switch ID
Priority
Description
The switches in the stack must have unique ID
numbers, in the range of 1 to 4. You use the
numbers to identify and configure the switches in
the AlliedWare Plus software. The switches
display their ID numbers on the ID LEDs on the
front panels. Refer to "Specifying Ports in the
Command Line Interface" on page 58. Allied
Telesis recommends deciding on their ID
assignments before beginning the configuration
procedures. The master switch can have any ID
number, but the stack can be easier to manage if
you assign it the ID 1.
Switches use priority values to select the master
switch of the stack when they are powered on or
reset, simultaneously. The range of 0 to 255. The
default value is 128. The lower the value, the
higher the priority. The switch with the lowest
priority number becomes the master switch.
If switches have the same priority number, they
select the master by comparing their MAC
addresses. Again, as with priority numbers, the
lower the MAC address, the higher the priority.
Switches do not use the priority values or MAC
addresses to select the master switch when they
are powered on sequentially. In this situation, the
first switch powered on becomes the master
switch, regardless of its priority number or MAC
address.
Allied Telesis recommends setting each switch's
priority value to match its ID value. This can
protect the stack's configuration if you later add
more switches to an existing stack. It can also
make it possible to know the order in which
switches assume the master role if the primary
master fails or is powered off.
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