QUESTION: In the Spectrum AlertMap file, I would like to understand how the second number in the "(1,2)" works.
ANSWER: The second number in the "(1,2)" represents the "instance variable id" where the instance of the variable is stored. Some traps send variables from a table. If so, the instance from the table could contain valuable information. For example, in the case of interface traps, the instance is the ifIndex of the interface where the issue was detected.
ADDITIONAL INFORMATION: The following details can be seen in Appendix A of the "Event Configuration User Guide" for Spectrum 9.4 and below and in the "OID Map" section for Spectrum 10.0.
The instance variable ID stores the instance portion of the OID. If your variable binding identifies a particular object from a table variable within the trap MIB, it will likely include an instance ID. Any integer value can be used here; however, it must be different from the integer used for the value variable ID. A value of zero indicates that you do not want to store the value of the instance variable.