7.3.3 Switch states
This section describes the change processing after switch state and switch state transition.
- <Structure of this section>
(1) List of Switch States
The following table describes a list of switch states. Alphabetic abbreviations are used to identify the switch state in the log or at the command prompt.
|
Switch state |
Alphabetic characters Abbreviated name |
Description |
|---|---|---|
|
Initial state |
I |
After the switch is started, the switch state is set to one of the following:
|
|
Standalone |
S |
State of the device that does not make up the stack. |
|
(Master) |
M |
The state of the member switches that make up the stack and control other member switches. |
|
Backup |
B |
The state of the member switch that switches to the master switch when the stack is configured and the current master switch fails. |
(2) Change processing after switch state transition
When the switch state changes, the member switch performs the following processing to ensure correct operation in the switch state after the transition.
-
Initialization
-
Switched
These processes are called modification processes. The required change processing differs depending on the switch state before and after the transition. In addition, it takes time to process the change.
(a) Processing of change when transition from initial state to master occurs
When the switch state transitions from the initial state to the master state, initialization is performed to start transfer operation as a change process. A master switch that is initializing does not immediately add a member switch when it is connected to a member switch on a stack port. After initialization is complete, add the connected member switches.
(b) Change processing when transition from initial state to backup occurs
When the switch state transitions from the initial state to the backup state, initialization is performed to start the transfer operation as a change process. The backup switch that is being initialized restarts when there is no connection with the master switch. Therefore, if the master switch is stopped or restarted during backup switch initialization, packet forwarding cannot continue. After the backup switch has been initialized, it switches to the master switch when there is no connection with the master switch. Therefore, even if there is no connection to the master switch after initialization is complete, packet forwarding can continue if the backup switch port is up.
Note that you cannot execute operation commands from the master switch to display information or operate the backup switch that is being initialized. Re-execute after the backup switch has been initialized.
(c) Change processing when the transition from backup to master is made
When the switch state changes from Backup to Master, the switch is switched to operate as a new master switch as a change process. When the switched master switch is connected to a member switch on a stack port, it does not immediately add a member switch. After the switch is complete, add the connected member switches.