TRAP/INFORM notification

pysnmp.hlapi.v1arch.asyncore.sendNotification(snmpDispatcher, authData, transportTarget, notifyType, *varBinds, **options)

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.

  • snmpDispatcher (SnmpDispatcher) – Class instance representing asyncore-based asynchronous event loop and associated state information.

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

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

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

  • *varBinds (tuple of OID-value pairs or ObjectType or NotificationType) – One or more objects representing MIB variables to place into SNMP notification. It could be tuples of OID-values or ObjectType class instances of NotificationType objects.

    Besides user variable-bindings, SNMP Notification PDU requires at least two variable-bindings to be present:

    1. SNMPv2-MIB::sysUpTime.0 = <agent uptime>
    2. SNMPv2-SMI::snmpTrapOID.0 = <notification ID>

    When sending SNMPv1 TRAP, more variable-bindings could be present:

    1. SNMP-COMMUNITY-MIB::snmpTrapAddress.0 = <agent-IP>
    2. SNMP-COMMUNITY-MIB::snmpTrapCommunity.0 = <snmp-community-name>
    3. SNMP-COMMUNITY-MIB::snmpTrapEnterprise.0 = <enterprise-OID>

    If user does not supply some or any of the above variable-bindings or if they are at the wrong positions, the system will add/reorder the missing ones automatically.

    On top of that, some notification types imply including some additional variable-bindings providing additional details on the event being reported. Therefore it is generally easier to use NotificationType object which will help adding relevant variable-bindings.

Other Parameters:

**options – Request options:

  • lookupMib - load MIB and resolve response MIB variables at the cost of slightly reduced performance. Default is False.
  • cbFun (callable) - user-supplied callable that is invoked to pass SNMP response data or error to user at a later point of time. Default is None.
  • cbCtx (object) - user-supplied object passing additional parameters to/from cbFun. Default is None.


The SnmpDispatcher object may be expensive to create, therefore it is advised to maintain it for the lifecycle of the application/thread for as long as possible.

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.


>>> from pysnmp.hlapi.v1arch.asyncore import *
>>> snmpDispatcher = SnmpDispatcher()
>>> sendNotification(
>>>     snmpDispatcher,
>>>     CommunityData('public'),
>>>     UdpTransportTarget(('', 162)),
>>>     'trap',
>>>     NotificationType(ObjectIdentity('SNMPv2-MIB', 'coldStart')),
>>>     lookupMib=True
>>> )
>>> snmpDispatcher.transportDispatcher.runDispatcher()