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 %s, SNMP Engine %s, Context %s' % (transportAddress,
                                                                   contextEngineId.prettyPrint(),
                                                                   contextName.prettyPrint()))
       for name, val in varBinds:
           print('%s = %s' % (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.
