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

  • using Asyncio framework for network transport

  • 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

Requires Python 3.4 and later!

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

# Get the event loop for this thread
loop = asyncio.get_event_loop()

# 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.domainName + (1,),
    udp.UdpTransport().openServerMode(("127.0.0.1", 162)),
)

# UDP over IPv4, second listening interface/port
config.addTransport(
    snmpEngine,
    udp.domainName + (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
def cbFun(snmpEngine, stateReference, contextEngineId, contextName, varBinds, cbCtx):
    transportDomain, transportAddress = snmpEngine.msgAndPduDsp.getTransportInfo(
        stateReference
    )
    print(
        "Notification from {}, SNMP Engine {}, Context {}".format(
            transportAddress, 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)

# Run asyncio main loop
loop.run_forever()

Download script.

See also: library reference.