Allied Telesis SwitchBladex8112 Installation Manual page 308

Chapter 16: Building a Stack
308
 If the management software is version 5.4.3 or earlier, do not
continue. The switch has the older AT-SBx81CFC400 Controller
Fabric Card, which does not support stacking.
7. Do one of the following:

If you are configuring the first chassis of the stack, write down on
paper the software version number of the AlliedWare Plus
operating software on the active controller card. You will compare
it with the same information on the second chassis to confirm that
both units have the same version of management software. After
writing the information, go to "Activating the VCStack Plus Feature
License" on page 309.
 If you are configuring the second chassis, compare the version
number displayed by the SHOW SYSTEM command against the
version number you wrote down on paper from the first chassis. If
the two chassis have the same management software and the
version number is 5.4.4 or later, you may go to "Activating the
VCStack Plus Feature License" on page 309. If they are different,
you must upgrade the management software on one or both units
so that they have the same version. For upgrade instructions, refer
to the Software Reference for SwitchBlade x8100 Series Switches.
After updating the management software, go to "Activating the
VCStack Plus Feature License" on page 309.
Section III: Building a Stack with VCStack Plus