Transport tweaks

Listen on multiple network interfaces

Listen and respond to SNMP GET/SET/GETNEXT/GETBULK queries with the following options:

  • SNMPv2c
  • with SNMP community “public”
  • allow access to SNMPv2-MIB objects (1.3.6.1.2.1)
  • over IPv4/UDP, listening at 127.0.0.1:161 and 127.0.0.2:161 interfaces
  • using Twisted framework for network transport

Either of the following Net-SNMP commands will walk this Agent:

$ snmpwalk -v2c -c public 127.0.0.1 .1.3.6
$ snmpwalk -v2c -c public 127.0.0.2 .1.3.6
from twisted.internet import reactor
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdrsp, context
from pysnmp.carrier.twisted.dgram import udp

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

# Transport setup

# UDP over IPv4 at 127.0.0.1:161
config.addTransport(
    snmpEngine,
    udp.domainName + (1,),
    udp.UdpTwistedTransport().openServerMode(('127.0.0.1', 161))
)

# UDP over IPv4 at 127.0.0.2:161
config.addTransport(
    snmpEngine,
    udp.domainName + (2,),
    udp.UdpTwistedTransport().openServerMode(('127.0.0.2', 161))
)

# SNMPv2c setup

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

# Allow full MIB access for this user / securityModels at VACM
config.addVacmUser(snmpEngine, 2, 'my-area', 'noAuthNoPriv', (1, 3, 6, 1, 2, 1), (1, 3, 6, 1, 2, 1))

# Get default SNMP context this SNMP engine serves
snmpContext = context.SnmpContext(snmpEngine)

# Register SNMP Applications at the SNMP engine for particular SNMP context
cmdrsp.GetCommandResponder(snmpEngine, snmpContext)
cmdrsp.SetCommandResponder(snmpEngine, snmpContext)
cmdrsp.NextCommandResponder(snmpEngine, snmpContext)
cmdrsp.BulkCommandResponder(snmpEngine, snmpContext)

# Run Twisted main loop
reactor.run()

Download script.

See also: library reference.