CISCO-APPLIANCE-REDUNDANCY-MIB
This mib defines the SNMP objects to report the status of High Availability (HA) functionality in Cisco network management appliance devices. The HA functinality is achieved via the redundancy of network management appliance devices. An network management appliance is a device which combines hardware and software to provide specific network management services. Cisco WLSE, Wireless Service Engine (WLSE) is such an appliance. The High Availability is achieved via redundancy of appliances. This redundancy scheme is designed to support hardware or software failure of the appliances in a non- disruptive manner. Redundancy is achieved by configuring a cluster of two appliances with one common virtual IP address. The data is mirrored from the active appliance to the standby appliance at regular intervals. One of the appliances is in active mode, performing all normal functions. The other appliance is in warm standby mode; that is, the appliance is up but no application services are running. Both the active and standby appliances have their own IP addresses. The active appliance also owns the virtual IP address to which all the service requests are made. The active appliance and standby appliance periodically poll each other. If the standby appliance cannot reach the active appliance, it will become the active appliance. This is called a switchover event. The switchover can be caused by other causes, for example, via user commands. Both the active and standby appliances should implement this MIB and report any exceptions caused by switchover events.