To facilitate a failover from the primary node to the backup node, the primary transfers its active configuration to the backup.
Relaying configuration information is the first level of checkpointing . During the initial switch boot-up, the primary‘s configuration takes effect. During the initialization of a node, its configuration is read from the local flash. After the primary and backup nodes have been elected, the primary transfers its current active configuration to the backup. After the primary and backup nodes are synchronized, any configuration change you make to the primary is relayed to the backup and incorporated into the backup‘s configuration copy.
NoteTo ensure that all of the configuration commands in the backup‘s flash are updated, issue the save command after you make any changes. On a SummitStack, the save configuration command will normally save the primary node's configuration file to all active nodes in the SummitStack.
If a failover occurs, the backup node continues to use the primary‘s active configuration. If the backup determines that it does not have the primary‘s active configuration because a run-time synchronization did not happen, the switch or SummitStack reboots. Because the backup always uses the primary‘s active configuration, the active configuration remains in effect regardless of the number of failovers.
NoteIf you issue the reboot command before you save your configuration changes, the switch prompts you to save your changes. To keep your configuration changes, save them before you reboot the switch.