All standalone controllers should have at least one NIC port configured as a management interface. Select the Allow Admin option in the BUI to enable BUI connections on port 215 and CLI connections on ssh port 22.
All cluster installations should have at least one NIC port on each controller configured as a management interface as described above. In addition, the NIC instance number must be unique on each controller. For example, nodeA uses igb0 and nodeB uses igb1, so that neither may be used as a cluster data interface. In addition, these interfaces must be locked to the controller using the Configuration > Cluster option in the BUI. In some cases, this may require installation of an additional network interface card on each controller in a cluster configuration.
If access to the appliance data interfaces is impossible for any reason, the management network interface will maintain BUI and CLI access. During a cluster takeover, interfaces are taken down on the failed controller. So, locked interface configuration is required to gather diagnostic information from a failed controller.