Idle Module Role - Alcatel-Lucent OmniSwitch 6250-M Hardware User's Manual

Roles Within the Stack

Idle Module Role

Switches that are not assigned either the primary or secondary role in a stack are, by default, assigned the
role of idle modules. These idle modules operate similarly to Network Interface (NI) modules in a chassis-
based switch. It is the job of idle modules to send and receive traffic.
In the event of a management module failure within the stack, the idle module with the next lowest slot
number in the stack will automatically assume the secondary management role. In other words, if the
primary module in a stack goes down for any reason and the secondary takes over the primary manage-
ment role, the switch must now assign a new secondary module. The idle element with the next lowest slot
number assumes this new responsibility until the situation is corrected and all elements in the stack are
reloaded.
Note. Primary and secondary management modules also send and receive traffic on their Ethernet. The
primary management module is like an NI module with the added task of overall stack management; the
secondary management module is like an NI with the added responsibility of backing up the primary
module in the event of a primary module failure. In other words, all modules in the virtual chassis can send
and receive user data, regardless of their roles.
For more information on dynamic assignment of idle modules in a stack, refer to the diagram below:
Primary
Secondary
Idle
Idle
Primary
Secondary
Secondary Management Module Selection Using Saved Slot Information
page 6-12
Preliminary
Managing OmniSwitch 6250 Series Stacks
9/28/09
Four OmniSwitch 6250 Series switches are stacked; all switches are
1
connected via stacking cables. The stack is booted.
The primary and secondary management modules are dynamically
2
assigned using any of the methods outlined on pages
6-11 .
The system software automatically assigns the remaining elements
3
in the stack the idle module role. These modules act as Network
Interface (NI) modules.
In the event of a primary-to-secondary failover, the idle module
with the next-lowest slot number in the stack will assume the
secondary—or backup—management role.
OmniSwitch 6250 Series Hardware Users Guide
6-7 through
September 2009