Primary Management Module Selection - Alcatel-Lucent OmniSwitch 6850E Series Hardware User's Manual

Managing OmniSwitch 6850E Series Stacks

Primary Management Module Selection

For a stack of switches to operate as a virtual chassis, there must be a mechanism for dynamically select-
ing the switch within the stack that will assume the primary management role. OmniSwitches use three
different methods for selecting the primary switch. These methods are:
• Chassis MAC address
• Saved slot number
• Chassis uptime
Note. Information on secondary management module selection is provided on
dynamic assignment of idle module roles is provided on
Using the Chassis MAC Address
By default, the primary management role will be given to the switch with the lowest chassis MAC
address. However, for this to occur, all switches in the stack must be booted within 15 seconds of each
other. In addition, switches in the stack must have no preconfigured slot information. Because of these
two conditions, the MAC address method for selecting the primary module usually occurs with new "out
of the box" switches, or switches from which any preconfigured slot information has been cleared.
For more information on using the lowest MAC address to determine the primary switch in a stack, refer
to the diagram below:
00:d0:95:b2:3c:8e
00:d0:95:b2:2a:ab
00:d0:95:b2:1c:ff
00:d0:95:b2:5b:8d
00:d0:95:b2:3c:8e
00:d0:95:b2:2a:ab
Primary Module
00:d0:95:b2:5b:8d
Primary Management Module Selection Using the Lowest Chassis MAC Address
Note. During the boot process, all other switches in the stack are also dynamically assigned unique slot
numbers. As with the primary switch, these slot numbers are saved to the boot.slot.cfg file, located in the
/flash file directory of each switch. For more information on dynamic slot number assignment, refer to
"Slot Numbering" on page
OmniSwitch 6850E Series Hardware Users Guide
1
A stack of four switches is booted. All switches are powered
on within 15 seconds of each other. In addition, there is no
preconfigured slot information on any of the switches.
2
When the stack is booted, system software detects the lowest
MAC address. In this stacked configuration, the lowest
MAC address is 00:d0:95:b2:1c:ff.
3
The system software immediately assigns the correspond-
ing switch the primary management role. When the switch
is assigned as primary, it is also dynamically assigned the
lowest slot number in the stack—i.e., slot 1. This slot
number information is saved to the boot.slot.cfg file,
located in the switch's /flash file directory.
6-20.
January 2013
page
page 6-12.
Roles Within the Stack
6-10. Information on
page 6-7