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

Roles Within the Stack

Primary Management Module Selection

For a stack of OmniSwitch 6850 Series switches to operate as a virtual chassis, there must be a mecha-
nism for dynamically selecting the switch within the stack that will assume the primary management role.
OmniSwitch 6850 Series switches 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 condi-
tions, 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
page 4-6
A stack of four OmniSwitch 6850 Series switches is booted.
1
All switches are powered on within 15 seconds of each other.
In addition, there is no preconfigured slot information on any
of the switches.
When the stack is booted, system software detects the lowest
2
MAC address. In this stacked configuration, the lowest
MAC address is 00:d0:95:b2:1c:ff.
The system software immediately assigns the correspond-
3
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.
4-19.
OmniSwitch 6850 Series Hardware Users Guide
Managing OmniSwitch 6850 Series Stacks
page
page 4-11.
4-9. Information on
August 2007