Transport tweaks#

Serving multiple network interfaces#

Receive SNMP TRAP/INFORM messages with the following options:

SNMPv1/SNMPv2c
with SNMP community “public”
over IPv4/UDP, listening at 127.0.0.1:162 over IPv4/UDP, listening at 127.0.0.1:2162
print received data on stdout

Either of the following Net-SNMP commands will send notifications to this receiver:

$ snmptrap -v2c -c public 127.0.0.1:162 123 1.3.6.1.6.3.1.1.5.1 1.3.6.1.2.1.1.5.0 s test

$ snmpinform -v2c -c public 127.0.0.1:2162 123 1.3.6.1.6.3.1.1.5.1

from pysnmp.entity import engine, config
from pysnmp.carrier.asyncio.dgram import udp
from pysnmp.entity.rfc3413 import ntfrcv

# Create SNMP engine with autogenernated engineID and pre-bound
# to socket transport dispatcher
snmpEngine = engine.SnmpEngine()

# Transport setup

# UDP over IPv4, first listening interface/port
config.addTransport(
    snmpEngine,
    udp.DOMAIN_NAME + (1,),
    udp.UdpTransport().openServerMode(("127.0.0.1", 162)),
)

# UDP over IPv4, second listening interface/port
config.addTransport(
    snmpEngine,
    udp.DOMAIN_NAME + (2,),
    udp.UdpTransport().openServerMode(("127.0.0.1", 2162)),
)

# SNMPv1/2c setup

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


# Callback function for receiving notifications
# noinspection PyUnusedLocal,PyUnusedLocal,PyUnusedLocal
def cbFun(snmpEngine, stateReference, contextEngineId, contextName, varBinds, cbCtx):
    print(
        'Notification from ContextEngineId "{}", ContextName "{}"'.format(
            contextEngineId.prettyPrint(), contextName.prettyPrint()
        )
    )
    for name, val in varBinds:
        print(f"{name.prettyPrint()} = {val.prettyPrint()}")


# 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.openDispatcher()
except:
    snmpEngine.closeDispatcher()
    raise

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