Sending SNMP Traps and Informs
There are two types of SNMP notifications: Traps and Inform requests. The main difference between them is reliability. Traps are unacknowledged and thus unreliable because the sender does not know if the trap was received. SNMPv2 fixed this by introducing the Inform notifications, which can be regarded as acknowledged Traps. Inform sender can now wait for an acknowledgement from the receiver. If the acknowledgment did not arrive with a certain time interval, the notification can be resent.
At the same time, Informs put additional overhead on network and computational resources: original Inform notification should be kept in sender's memory until a response is received, it needs additional processing on receiver and increase traffic when is repeated.
 | Traps and Informs allow to find a balance between reliability and resources: for important notifications you can use Informs, while "ordinary" ones can be sent as Traps. |
Iotellect Network Manager can generate both types of SNMP notifications using Send SNMP Trap (sendSnmpTrap) action in Root context.
You can invoke Send SNMP Trap action manually by activating context menu of server node (
) in System Tree, choosing Network Management submenu and selecting Send SNMP Trap. Alternatively, you can configure traps to be sent in response to an alert -- see corrective actions for details.
Input Format
The action can be configured with parameters of the following format:
Name | Type | Description | Details | ||
trapType | String | Notification Type | Notification type: Trap or Inform. | ||
targetAddress | String | IP Address or Host Name | Address of the trap's receiver. | ||
port | Integer | Port | Port the trap will be sent to ( | ||
protocol | String | Protocol | Transport Protocol to be used to deliver trap ( | ||
timeout | Long | Timeout | Timeout before a confirmed request is resent or timed out (5 seconds by default). | ||
enterprise | String | Enterprise or Trap OID | Trap's Enterprise for SNMP version 1, or Trap/Inform's OID for SNMP versions 2(c) and 3. | ||
variableBindings | Data Table | Variable Bindings | Variables bindings to be associated with the trap. Bindings are defined in a table with the following format: | ||
Name | Type | Description | |||
|---|---|---|---|---|---|
variableBindingsOID | String | Variable OID | |||
variableBindingsType | Integer | Variable Type | |||
variableBindingsValue | String | Variable Value | |||
snmpVersion | Integer | SNMP Protocol Version | SNMP version. | ||
community | String | Community | Community string (for notifications of SNMP versions 1 and 2) | ||
userName | String | Username | Username for version 3 notifications. Note, that system tries to find authentication and privacy passwords in SNMP Users Table (using specified Username and Engine ID). Thus, a record for the user must exist in the table. | ||
engineId | Data | Authoritative Engine ID | Binary-encoded engine ID. Required for version 3 notifications, and must be configured on the physical device. | ||
securityLevel | Integer | Security Level | Security level for version 3 notifications. | ||
Output Format
The action returns nothing for Traps. For Informs, the response is returned in the following format:
Name | Type | Description | Details | ||
variableBindings | Data Table | Variable Bindings | Data returned as response to Inform. Bindings are defined in a table with the following format: | ||
Name | Type | Description | |||
|---|---|---|---|---|---|
variable | String | Variable | |||
value | String | Value | |||
errorMessage | String | Error | Textual description of the success/error status. | ||
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