# Advanced topic

## Send crafted TRAP PDU

Initialize TRAP PDU and pass it over to unified SNMPv3 message processing framework for further treatment.

- SNMPv2c

- with community name ‘public’

- over IPv4/UDP

- send TRAP notification

- initialize TRAP PDU with the following var-binds: 1.3.6.1.2.1.1.3.0 = 123 1.3.6.1.6.3.1.1.4.1.0 = 1.3.6.1.6.3.1.1.5.1

Functionally similar to:

$ snmptrap -v2c -c public demo.snmplabs.com 0 1.3.6.1.6.3.1.1.5.1

    from pysnmp.entity import engine, config
    from pysnmp.carrier.asyncore.dgram import udp
    from pysnmp.entity.rfc3413 import ntforg
    from pysnmp.proto.api import v2c

    # Create SNMP engine instance
    snmpEngine = engine.SnmpEngine()

    # SecurityName <-> CommunityName mapping
    config.addV1System(snmpEngine, 'my-area', 'public')

    # Specify security settings per SecurityName (SNMPv2c -> 1)
    config.addTargetParams(snmpEngine, 'my-creds', 'my-area', 'noAuthNoPriv', 1)

    # Setup transport endpoint and bind it with security settings yielding
    # a target name
    config.addTransport(
        snmpEngine,
        udp.domainName,
        udp.UdpSocketTransport().openClientMode()
    )

    # Create named target
    config.addTargetAddr(
        snmpEngine, 'my-nms',
        udp.domainName, ('104.236.166.95', 162),
        'my-creds'
    )

    # *** SNMP engine configuration is complete by this line ***

    # Create SNMP v2c TRAP PDU with defaults
    trapPDU = v2c.TrapPDU()
    v2c.apiTrapPDU.setDefaults(trapPDU)

    # Set custom var-binds to TRAP PDU
    v2c.apiTrapPDU.setVarBinds(
        trapPDU, [
            # sysUpTime
            (v2c.ObjectIdentifier('1.3.6.1.2.1.1.3.0'), v2c.TimeTicks(123)),
            # snmpTrapPDU
            ((1, 3, 6, 1, 6, 3, 1, 1, 4, 1, 0), v2c.ObjectIdentifier((1, 3, 6, 1, 6, 3, 1, 1, 5, 1)))
        ]
    )

    # Create Notification Originator App instance.
    ntfOrg = ntforg.NotificationOriginator()

    # Error/confirmation receiver
    # noinspection PyUnusedLocal,PyUnusedLocal,PyUnusedLocal,PyUnusedLocal,PyUnusedLocal
    def cbFun(snmpEngine, sendRequestHandle, errorIndication,
              errorStatus, errorIndex, varBinds, cbCtx):
        print('Notification %s, status - %s' % (
            sendRequestHandle, errorIndication and errorIndication or 'delivered'
        )
              )

    # Build and submit notification message to dispatcher
    ntfOrg.sendPdu(
        snmpEngine,
        # Notification targets
        'my-nms',  # target address
        None, '',  # contextEngineId, contextName
        trapPDU,
        cbFun
    )

    print('Notification is scheduled to be sent')

    # Run I/O dispatcher which would send pending message and process response
    snmpEngine.transportDispatcher.runDispatcher()

`Download` script.

See also: library reference.