You can configure an SNMP agent on a Citrix NetScaler instance to generate asynchronous events called traps. Traps are generated whenever there are abnormal conditions on the NetScaler instance. The traps are then sent to a remote device called a trap listener, which then alerts you to the abnormal condition on the NetScaler instance.
Alternatively, you can query the SNMP agent for system-specific information from a remote device called an SNMP manager. The agent then searches the management information base (MIB) for requested data and sends the data to the SNMP manager.
Support for SNMP Version 3 Traps on NetScaler MAS for NetScaler Instances
SNMP version 3 traps provides security capabilities such as authentication and encryption by using the credentials of SNMP users.
When you add an instance to the NetScaler MAS server, the server implicitly adds itself as a trap destination for the instance during discovery. This allows the NetScaler MAS server to receive traps generated on the instance. When you add an SNMP v3 as a trap destination on the NetScaler MAS server, it is bound to an SNMP user’s credentials, the SNMP group, and the SNMP view.
If the trap destination is already present on the managed instance, NetScaler MAS will only verify the trap destination against its user and security level. If the discovery process is successful, and the NetScaler MAS server starts to receive traps generated on the NetScaler instance, an new event is generated. This event will notify the administrator that a new SNMP user has been added to an instance and the traps being sent from that instance must be authenticated by the NetScaler MAS server.