Pysnmp can't resolve OID's from snmp trap

Question

I'm trying to resolve the OIDs that are received on an SNMP Trap from an HP switch stack but they only resolve down to a certain level and stop. It's like the HP MIBs are not being loaded. It's unclear from all the documentation I can find on pysnmp if this is the appropriate way to add custom MIBs and resolve OIDs from a trap. MIBs can be downloaded here .

from pysnmp.entity import engine, config
from pysnmp.carrier.asyncore.dgram import udp
from pysnmp.smi import view, builder, rfc1902
from pysnmp.entity.rfc3413 import ntfrcv, mibvar

# Create SNMP engine with autogenernated engineID and pre-bound
# to socket transport dispatcher
snmpEngine = engine.SnmpEngine()
build = snmpEngine.getMibBuilder()
build.addMibSources(builder.DirMibSource("C:/Users/t/Documents/mibs"))
viewer = view.MibViewController(build)

# Transport setup

# UDP over IPv4, first listening interface/port
config.addTransport(
    snmpEngine,
    udp.domainName + (1,),
    udp.UdpTransport().openServerMode(('0.0.0.0', 162))
)

# SNMPv1/2c setup

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


# Callback function for receiving notifications
# noinspection PyUnusedLocal,PyUnusedLocal,PyUnusedLocal
def cbFun(snmpEngine, stateReference, contextEngineId, contextName, varBinds, cbCtx):
    print('Notification from ContextEngineId "%s", ContextName "%s"' % (contextEngineId.prettyPrint(),
                                                                        contextName.prettyPrint()))
    for name, val in varBinds:
        print(name)
        symbol = rfc1902.ObjectIdentity(name).resolveWithMib(viewer).getMibSymbol()
        print(symbol[1])



# Register SNMP Application at the SNMP engine
ntfrcv.NotificationReceiver(snmpEngine, cbFun)

snmpEngine.transportDispatcher.jobStarted(1)  # this job would never finish

# Run I/O dispatcher which would receive queries and send confirmations
try:
    snmpEngine.transportDispatcher.runDispatcher()
except:
    snmpEngine.transportDispatcher.closeDispatcher()
    raise

Output upon receiving a trap:

Notification from ContextEngineId "0x80004fb8056ed891e8", ContextName ""
1.3.6.1.2.1.1.3.0
sysUpTime
1.3.6.1.6.3.1.1.4.1.0
snmpTrapOID
1.3.6.1.6.3.18.1.3.0
snmpTrapAddress
1.3.6.1.6.3.18.1.4.0
snmpTrapCommunity
1.3.6.1.6.3.1.1.4.3.0
snmpTrapEnterprise
1.3.6.1.4.1.11.2.14.11.5.1.7.1.29.1.9
enterprises
1.3.6.1.4.1.11.2.14.11.5.1.7.1.29.1.0.1
enterprises
1.3.6.1.4.1.11.2.14.11.5.1.7.1.29.1.0.2
enterprises
1.3.6.1.4.1.11.2.14.11.5.1.7.1.29.1.0.3
enterprises
1.3.6.1.4.1.11.2.14.11.5.1.7.1.29.1.0.4
enterprises
1.3.6.1.4.1.11.2.14.11.5.1.7.1.29.1.0.5
enterprises

As you can see many distinct OIDs just resolve to "enterprises". I am using pysnmp 4.4.4.

Answer 1

Yes, it seems that only the core MIBs are loaded.

If you want to follow this quite low-level path, then you need to pre-compile all your ASN.1 MIBs (those you pulled from HPE site) with the mibdump tool into pysnmp format. Then put those *.py files into some directory and point pysnmp to it through build.addMibSources(builder.DirMibSource()) call.

Also, make sure to pre-load up all those MIBs at once on startup by invoking build.loadModules() (w/o arguments).