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"""
Multiple SNMP Engines
+++++++++++++++++++++
Run multiple SNMP Engines each with a complete Command Responder.
Bind each SNMP Engine to a dedicated network transport endpoint:
* IPv4/UDP, listening at 127.0.0.1:161
* IPv4/UDP, listening at 127.0.0.2:161
Each Command Responder will respond to SNMP GET/SET/GETNEXT/GETBULK
queries with the following options:
* SNMPv3
* with USM user 'usr-md5-des', auth: MD5, priv DES
* allow read access to SNMPv2-MIB objects (1.3.6)
* allow write access to SNMPv2-MIB objects (1.3.6.1.2.1)
The following Net-SNMP commands will walk the first and the second
Agent respectively:
| $ snmpwalk -Ob -v3 -u usr-md5-des -l authPriv -A authkey1 -X privkey1 127.0.0.1 usmUserEntry
| $ snmpwalk -Ob -v3 -u usr-md5-des -l authPriv -A authkey1 -X privkey1 127.0.0.2 usmUserEntry
Notice differently configured snmpEngineId's in usmUserEntry columns.
"""#
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdrsp, context
from pysnmp.proto import rfc1902
from pysnmp.carrier.asyncore.dispatch import AsyncoreDispatcher
from pysnmp.carrier.asyncore.dgram import udp
# Configuration parameters for each of SNMP Engines
snmpEngineInfo = (
('0102030405060708', udp.domainName + (0,), ('127.0.0.1', 161)),
('0807060504030201', udp.domainName + (1,), ('127.0.0.2', 161))
)
# Instantiate the single transport dispatcher object
transportDispatcher = AsyncoreDispatcher()
# Setup a custom data routing function to select snmpEngine by transportDomain
transportDispatcher.registerRoutingCbFun(lambda td, t, d: td)
# Instantiate and configure SNMP Engines
for snmpEngineId, transportDomain, transportAddress in snmpEngineInfo:
# Create SNMP engine with specific engineID
snmpEngine = engine.SnmpEngine(rfc1902.OctetString(hexValue=snmpEngineId))
# Register SNMP Engine object with transport dispatcher. Request incoming
# data from specific transport endpoint to be funneled to this SNMP Engine.
snmpEngine.registerTransportDispatcher(transportDispatcher, transportDomain)
# Transport setup
# UDP over IPv4
config.addTransport(
snmpEngine,
transportDomain,
udp.UdpTransport().openServerMode(transportAddress)
)
# SNMPv3/USM setup
# user: usr-md5-des, auth: MD5, priv DES
config.addV3User(
snmpEngine, 'usr-md5-des',
config.usmHMACMD5AuthProtocol, 'authkey1',
config.usmDESPrivProtocol, 'privkey1'
)
# Allow full MIB access for this user / securityModels at VACM
config.addVacmUser(snmpEngine, 3, 'usr-md5-des', 'authPriv', (1, 3, 6), (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)
# Register an imaginary never-ending job to keep I/O dispatcher running forever
transportDispatcher.jobStarted(1)
# Run I/O dispatcher which would receive queries and send responses
try:
transportDispatcher.runDispatcher()
except:
transportDispatcher.closeDispatcher()
raise
|
