User guide

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:

Secondary Management Module Selection Using Saved Slot Information

Four OmniSwitch 6450 switches are stacked; all switches

are connected via stacking cables. The stack is booted.

Primary

Secondary

The primary and secondary management modules are

dynamically assigned using any of the methods outlined on

pages

6-7 through 6-11.

Idle

Primary

Secondary

The system software automatically assigns the remain-

ing elements 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.