# TRAP/INFORM notification

`pysnmp.hlapi.asyncore.``sendNotification`(snmpEngine, authData, transportTarget, contextData, notifyType, varBinds, cbFun=None, cbCtx=None, lookupMib=False)

  Send SNMP notification.

  Based on passed parameters, prepares SNMP TRAP or INFORM notification (RFC 1905#section-4.2.6) and schedules its transmission by 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

    - cbFun (callable) – user-supplied callable that is invoked to pass SNMP response to INFORM notification or error to user at a later point of time. The cbFun callable is never invoked for TRAP notifications.

    - cbCtx (object) – user-supplied object passing additional parameters to/from cbFun.

    - lookupMib (bool) – lookupMib - load MIB and resolve response MIB variables at the cost of slightly reduced performance. Default is True.

  Notes

  User-supplied cbFun callable must have the following call signature:

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

  - sendRequestHandle (int): Unique request identifier. Can be used for matching multiple ongoing INFORM notifications with received responses.

  - errorIndication (str): True value indicates SNMP engine error.

  - 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 in exactly the same order as varBinds in request.

  - cbCtx : Original user-supplied object.

  Returns

    sendRequestHandle (int) – Unique request identifier. Can be used for matching received responses with ongoing INFORM requests. Returns None for TRAP notifications.

  Raises

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

  Examples

      >>> from pysnmp.hlapi.asyncore import *
      >>>
      >>> snmpEngine = SnmpEngine()
      >>> sendNotification(
      ...     snmpEngine,
      ...     CommunityData('public'),
      ...     UdpTransportTarget(('demo.snmplabs.com', 162)),
      ...     ContextData(),
      ...     'trap',
      ...     NotificationType(ObjectIdentity('SNMPv2-MIB', 'coldStart')),
      ... )
      >>> snmpEngine.transportDispatcher.runDispatcher()
      >>>