Transport tweaks
****************


Serving multiple network interfaces
===================================

Receive SNMP TRAP/INFORM messages with the following options:

* SNMPv1/SNMPv2c

* with SNMP community "public"

* listen on two local network interfaces:
     * IPv4/UDP, listening at 127.0.0.1:162

     * IPv4/UDP, listening at 127.0.0.1:2162

* using Twisted 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

   from twisted.internet import reactor
   from pysnmp.entity import engine, config
   from pysnmp.carrier.twisted.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.domainName + (1,),
       udp.UdpTwistedTransport().openServerMode(('127.0.0.1', 162))
   )

   # UDP over IPv4, second listening interface/port
   config.addTransport(
       snmpEngine,
       udp.domainName + (2,),
       udp.UdpTwistedTransport().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 "%s", Context "%s"' % (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 Twisted main loop
   reactor.run()

"Download" script.

See also: library reference.
