SNMP parameters

The snmp traps command supports the following parameters:

var
trap-id
trigger
edge-1 and edge-2
edge-1-direction and edge-2-direction
interval
interval-offset
rate-interval
backoff-calculator
backoff-step
backoff-multiplier
priority
message

The var parameter

The var parameter associates a user-defined trap name (specified by the trapname variable in the snmp traps command) with a specific MIB object. The MIB object is specified in the value field of the snmp traps command. It must be of the form snmp.oid, where oid is an Object Identifier (OID).

Note
A short list of the Network Appliance MIB OIDs is available in the traps.dat file. The file is located in the /etc/mib directory on your filer. For more information about a particular OID, see the MIB.

The trap-id parameter

The trap-id parameter tags a trap identifier (trap-id) to the trap being sent. Each trap defined in the Network Appliance custom MIB has its own identifier. For each user-defined trap the trap manager uses the trap-id associated with the trap's priority.

The trigger parameter

The trigger parameter specifies the type of triggers that you can set for a trap. If a trap is triggered, data about the event that caused the trigger is sent to the network management stations. You can specify the following values for the trigger parameter in the value variable field of the snmp traps command:

single-edge-trigger--Fires a trap and sends data when the value of the trap's MIB variable crosses an edge (a value that you specify) for the first time.
double-edge-trigger--Fires a trap and sends data when either of two edges is crossed. A double-edge-trigger enables you to set two edges, each with its own direction.
level-trigger--Fires a trap and sends data whenever the trap's value crosses a specified edge value.
change-trigger--Keeps track of the last value received from the trap. If the current value differs from the previously received value, the trap is triggered.
always-trigger--Enables a trap to always trigger at the specified evaluation interval (specified by the interval parameter discussed later in this section). For example, a trap can trigger every 24 hours for the agent to send the total number of CIFS operations to an SNMP manager.

The edge-1 and edge-2 parameters

The edge-1 and edge-2 parameters of a trap specify the threshold values that are compared during trap evaluation to determine whether to fire a trap and send data.

The edge-1 parameter specifies the value for the edge in a single-edge-triggered trap or the first edge in a double-edge-triggered trap. The default value for the edge-1 parameter in the value variable field of the snmp traps command is MAXINT.

The edge-2 parameter specifies the value for the second edge in a double-edge-triggered trap. The default value for the edge-2 parameter in the value variable field of the snmp traps command is 0.

The edge-1-direction and edge-2-direction parameters

The edge-1-direction and edge-2-direction parameters let you set or change the direction that is used to evaluate a trap. The edge-triggered traps only send data when the edge is crossed in either the up or down direction. The default values for the edge-1-direction and the edge-2-direction parameters in the value variable field of the snmp traps command are

edge-1-direction--up
edge-2-direction--down
Note
The direction values are printed on the same line as the edge value when you run the snmp traps command.

The interval parameter

The interval parameter is the time, in seconds, between evaluations of a trap. A trap can only send data as often as it is evaluated, even if the edge values are exceeded sooner. The default value for the interval parameter in the value variable field of the snmp traps command is 3600.

Note
The interval value for the Network Appliance predefined traps is 60, or one minute.

The interval-offset parameter

The interval-offset parameter is the amount of time, in seconds, until the first trap evaluation. The default value for the interval-offset parameter in the value variable field of the snmp traps command is 0. You can set it to a nonzero value to prevent too many traps from being evaluated at once (at system startup, for example).

The rate-interval parameter

The rate-interval parameter specifies the time, in seconds, in which the change in value of a trap's variable (rate of change) is expressed. If the rate-interval value is set for a trap, the samples of data obtained at the interval points (set using the interval parameter) for a trap variable are used to calculate the rate of change. If the calculated value exceeds the value set for the edge-1 or edge-2 parameter, the trap is fired.

For example, to obtain the number of CIFS operations per hour, you specify a rate-interval of 3600. If rate-interval is set to 0, no sampling at interval points occurs and trap evaluation proceeds as with any other kind of trap. The default value for the rate-interval parameter in the value variable field of the snmp traps command is 0.

The backoff-calculator parameter

The backoff-calculator parameter enables you to change the trap evaluation interval for a trap after a trap fires. After a trap fires and sends data, you might not want it to be evaluated so often. For instance, you might want to know within a minute of when a file system is full, but only want to be notified every hour thereafter that it is still full. The backoff-calculator parameter can take the following values in the value variable field:

step-backoff
exponential-backoff
no-backoff

The default value for the backoff-calculator parameter in the value variable field of the snmp traps command is no-backoff.

The backoff-step parameter

The backoff-step parameter specifies the number of seconds by which the trap evaluation interval is increased. If a trap interval is 10 and its backoff-step is 3590, the trap is evaluated every 10 seconds until it fires the first time and sends data, and once an hour thereafter. The default value for the backoff-step parameter in the value variable field of the snmp traps command is 0.

The backoff-multiplier parameter

The backoff-multiplier parameter specifies the value by which to multiply a trap's evaluation interval each time it fires. If you set backoff-calculator to exponential-backoff and backoff-multiplier to 2, the interval doubles each time the trap fires. The default value for the backoff-multiplier parameter in the value variable field of the snmp traps command is 1.

The priority parameter

The priority parameter sets the priority of a trap. If several traps are scheduled to fire at the same time, you can use the priority parameter to decide which trap is serviced first. The possible values for the priority parameter in the value variable field of the snmp traps command, from highest to lowest, are as follows:

emergency
alert
critical
error
warning
notification
informational
debug

The default value for the priority parameter in the value variable field of the snmp traps command is notification.

The message parameter

The message parameter specifies a message that goes out with a trap. The message can be a string of text or of the form snmp.oid. If an OID is specified, the result of evaluating that OID is sent. If the message parameter is not specified, the default value sent when a trap fires is a string that shows the OID value that triggered the trap. For example, the following string is sent to the network management stations for the trap cpuUpTime if the message parameter is not set:

cpuUpTime == 10562288.priority == notification

Note
If the message is a string that includes spaces, you must enclose the string in quotation marks (" ").