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About Automatic Failover

You can create a NetMRI failover pair using two NetMRI appliances, in which one acts as the primary appliance and the other as the secondary appliance. A failover pair provides a backup or redundant operational mode between the primary and secondary appliances so you can greatly reduce service downtime when one of them is out of service. You can configure two Operation Center (OC) appliances, collector appliances, or standalone appliances to form a failover pair.

In a failover pair, the primary appliance actively discovers and manages network devices and serves the Web UI and the CLI over the shared VIP address while the secondary appliance constantly keeps its database synchronized with the primary. Although you can access a failover pair using either the VIP address of the failover pair or the management IP address of the primary appliance, using the management IP is not recommended because, during a failover, the roles of the primary and secondary appliances reverse and the management IP becomes unreachable. Accessing the failover pair using the VIP address ensures that you are contacting the active primary appliance. Note that during a failover, all active connections between the NetMRI appliances and the network devices are disrupted and all ongoing processes fail. Also, all active Web UI and CLI sessions are disrupted during a failover and all users with active sessions must reconnect and log in again after the secondary appliance assumes the role of the primary appliance.

Note the following about the automatic failover feature:

  • Failover pair is supported only on NetMRI NT-1400, NT-2200, and NT-4000 (G8 only) appliances. It is not supported on NetMRI virtual appliances.
  • Failover is supported in NetMRI 7.1.1 and later releases.
  • Collector failover is supported in NetMRI 7.1.2 and later releases.
  • Both the primary and secondary must be of the same appliance model and same software version number.
  • The management IP address of both the primary and secondary must be on the same subnet.
  • The VIP address, shared by the primary and secondary, must be on the same subnet as the management IP address.