cmAlarmIndex is a read-only integer between 1 and 65535 uniquely identifying a threshold-monitoring entry in this RMON-style alarm table, where each entry defines a periodic diagnostic sample of some object on the device. An administrator uses this index to manage multiple independent threshold-alarm configurations simultaneously, each watching a different variable. For example, an operator setting up separate alarms for CPU load and for a specific interface error counter would create two distinct entries, each with its own cmAlarmIndex.