# TRAP/INFORM notification

`pysnmp.hlapi.twisted.``sendNotification`(snmpEngine, authData, transportTarget, contextData, notifyType, varBinds, **options)

  Sends SNMP notification.

  Based on passed parameters, prepares SNMP TRAP or INFORM message (RFC 1905#section-4.2.6) and schedules its transmission by `twisted` I/O framework at a later point of time.

  Parameters

    - snmpEngine (`SnmpEngine`) – Class instance representing SNMP engine.

    - authData (`CommunityData` or `UsmUserData`) – Class instance representing SNMP credentials.

    - transportTarget (`UdpTransportTarget` or `Udp6TransportTarget`) – Class instance representing transport type along with SNMP peer address.

    - contextData (`ContextData`) – Class instance representing SNMP ContextEngineId and ContextName values.

    - notifyType (str) – Indicates type of notification to be sent. Recognized literal values are trap or inform.

    - varBinds (tuple) – Single `NotificationType` class instance representing a minimum sequence of MIB variables required for particular notification type. Alternatively, a sequence of `ObjectType` objects could be passed instead. In the latter case it is up to the user to ensure proper Notification PDU contents.

  Other Parameters

    **options –

    Request options:

    > - lookupMib - load MIB and resolve response MIB variables at the cost of slightly reduced performance. Default is True.

  Returns

    deferred (`Deferred`) – Twisted Deferred object representing work-in-progress. User is expected to attach his own success and error callback functions to the Deferred object though `addCallbacks()` method.

  Raises

    PySnmpError – Or its derivative indicating that an error occurred while performing SNMP operation.

  Notes

  User success callback is called with the following tuple as its first argument:

  - errorStatus (str) : True value indicates SNMP PDU error.

  - errorIndex (int) : Non-zero value refers to varBinds[errorIndex-1]

  - varBinds (tuple) : A sequence of `ObjectType` class instances representing MIB variables returned in SNMP response.

  User error callback is called with errorIndication object wrapped in `Failure` object.

  Examples

      >>> from twisted.internet.task import react
      >>> from pysnmp.hlapi.twisted import *
      >>>
      >>> def success(args):
      ...     (errorStatus, errorIndex, varBinds) = args
      ...     print(errorStatus, errorIndex, varBind)
      ...
      >>> def failure(errorIndication):
      ...     print(errorIndication)
      ...
      >>> def run(reactor):
      ...     d = sendNotification(SnmpEngine(),
      ...                          CommunityData('public'),
      ...                          UdpTransportTarget(('demo.snmplabs.com', 162)),
      ...                          ContextData(),
      ...                          'trap',
      ...                          NotificationType(ObjectIdentity('IF-MIB', 'linkDown')))
      ...     d.addCallback(success).addErrback(failure)
      ...     return d
      ...
      >>> react(run)
      (0, 0, [])
      >>>