Python PYSNMP avoid sending DISMAN-EVENT-MIB event as part of traps

We are trying to send a custom SNMP notification using PYSNMP module using custom MIB's but when it send the notification we get an DISMAN-EVENT-MIB::sysUpTimeInstance event also as part of the notification. We want to avoid the same. Below is the sample script

from pysnmp.entity.rfc3413.oneliner import ntforg

ntfOrg = ntforg.NotificationOriginator()

errorIndication, errorStatus, errorIndex, varBinds = ntfOrg.sendNotification(
    ntforg.CommunityData('public'),
    ntforg.UdpTransportTarget(('localhost', 162)),
    'inform',
    ntforg.MibVariable('SNMPv2-MIB', 'sysDescr'),
    ( ntforg.MibVariable('SNMPv2-MIB', 'sysDescr', 0), 'Hello' ),
    lookupNames=True, lookupValues=True
)

if errorIndication:
    print('Notification not sent: %s' % errorIndication)
elif errorStatus:
    print('Notification Receiver returned error: %s @%s' %
          (errorStatus, errorIndex))
else:
    for name, val in varBinds:
        print('%s = %s' % (name.prettyPrint(), val.prettyPrint()))

Below is the out I get in /var/log/messages

Jun  1 18:56:14 localhost snmptrapd[1194]: 2015-06-01 18:56:14 localhost [UDP: [127.0.0.1]:56469->[127.0.0.1]:162]:
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (0) 0:00:00.00 SNMPv2-MIB::snmpTrapOID.0 = OID: SNMPv2-MIB::sysDescr   SNMPv2-MIB::sysDescr.0 = STRING: Hello

So how we can avoid not sending DISMAN-Event as part of it.

Solution

A well-formed SNMP v2c/v3 Notification must contain two specific OIDs at the beginning of its var-bindings list. Those OIDs are sysUpTime and snmpTrapOID. If you leave them out, that would be a violation of the protocol. So pysnmp adds those OIDs for you into PDU.

If that's OK to send malformed packet, you have two options:

If all SNMP versions support is required, use the latest (CVS) version of pysnmp library along with its Standard SNMP Applications API. The pysnmp.entity.rfc3413.ntforg.NotificationOriginator.sendPdu() method accepts a user-supplied PDU object.
If performance is important and SNMPv3 is not required, use packet-level trap sender.

Both APIs will let you sending your own PDU with whatever variable-bindings you consider appropriate in your situation.