MIB walking operations#
Walk Agent MIB (SNMPv1)#
Perform SNMP GETNEXT operation with the following options:
with SNMPv1, community ‘public’
over IPv4/UDP
to an Agent at demo.pysnmp.com:161
for OID in tuple form
This script performs similar to the following Net-SNMP command:
$ snmpwalk -v1 -c public -ObentU demo.pysnmp.com 1.3.6
from pysnmp.carrier.asyncio.dispatch import AsyncioDispatcher
from pysnmp.carrier.asyncio.dgram import udp
from pyasn1.codec.ber import encoder, decoder
from pysnmp.proto import api
# Protocol version to use
pMod = api.PROTOCOL_MODULES[api.SNMP_VERSION_1]
# pMod = api.PROTOCOL_MODULES[api.SNMP_VERSION_2C]
# SNMP table header
headVars = [pMod.ObjectIdentifier((1, 3, 6))]
# Build PDU
reqPDU = pMod.GetNextRequestPDU()
pMod.apiPDU.setDefaults(reqPDU)
pMod.apiPDU.setVarBinds(reqPDU, [(x, pMod.null) for x in headVars])
# Build message
reqMsg = pMod.Message()
pMod.apiMessage.setDefaults(reqMsg)
pMod.apiMessage.setCommunity(reqMsg, "public")
pMod.apiMessage.setPDU(reqMsg, reqPDU)
# noinspection PyUnusedLocal
def cbRecvFun(
transportDispatcher,
transportDomain,
transportAddress,
wholeMsg,
reqPDU=reqPDU,
headVars=headVars,
):
while wholeMsg:
rspMsg, wholeMsg = decoder.decode(wholeMsg, asn1Spec=pMod.Message())
rspPDU = pMod.apiMessage.getPDU(rspMsg)
# Match response to request
if pMod.apiPDU.getRequestID(reqPDU) == pMod.apiPDU.getRequestID(rspPDU):
# Check for SNMP errors reported
errorStatus = pMod.apiPDU.getErrorStatus(rspPDU)
if errorStatus and errorStatus != 2:
raise Exception(errorStatus)
# Format var-binds table
varBindTable = pMod.apiPDU.getVarBindTable(reqPDU, rspPDU)
# Report SNMP table
for tableRow in varBindTable:
for name, val in tableRow:
print(
"from: {}, {} = {}".format(
transportAddress, name.prettyPrint(), val.prettyPrint()
)
)
# Stop on EOM
for oid, val in varBindTable[-1]:
if not isinstance(val, pMod.Null):
break
else:
transportDispatcher.jobFinished(1)
continue
# Generate request for next row
pMod.apiPDU.setVarBinds(
reqPDU, [(x, pMod.null) for x, y in varBindTable[-1]]
)
pMod.apiPDU.setRequestID(reqPDU, pMod.getNextRequestID())
transportDispatcher.sendMessage(
encoder.encode(reqMsg), transportDomain, transportAddress
)
return wholeMsg
transportDispatcher = AsyncioDispatcher()
transportDispatcher.registerRecvCbFun(cbRecvFun)
transportDispatcher.registerTransport(
udp.DOMAIN_NAME, udp.UdpAsyncioTransport().openClientMode()
)
transportDispatcher.sendMessage(
encoder.encode(reqMsg), udp.DOMAIN_NAME, ("demo.pysnmp.com", 161)
)
transportDispatcher.jobStarted(1)
transportDispatcher.runDispatcher(3)
transportDispatcher.closeDispatcher()
Download
script.
Bulk walk Agent MIB (SNMPv2c)#
Perform SNMP GETBULK operation with the following options:
with SNMPv2c, community ‘public’
over IPv4/UDP
to an Agent at demo.pysnmp.com:161
for OID in tuple form
with non-repeaters=0 and max-repeaters=25
This script performs similar to the following Net-SNMP command:
$ snmpbulkwalk -v2c -c public -ObentU -Cn0 -Cr25 demo.pysnmp.com 1.3.6
from pysnmp.carrier.asyncio.dispatch import AsyncioDispatcher
from pysnmp.carrier.asyncio.dgram import udp
from pyasn1.codec.ber import encoder, decoder
from pysnmp.proto.api import v2c
# SNMP table header
headVars = [v2c.ObjectIdentifier((1, 3, 6))]
# Build PDU
reqPDU = v2c.GetBulkRequestPDU()
v2c.apiBulkPDU.setDefaults(reqPDU)
v2c.apiBulkPDU.setNonRepeaters(reqPDU, 0)
v2c.apiBulkPDU.setMaxRepetitions(reqPDU, 25)
v2c.apiBulkPDU.setVarBinds(reqPDU, [(x, v2c.null) for x in headVars])
# Build message
reqMsg = v2c.Message()
v2c.apiMessage.setDefaults(reqMsg)
v2c.apiMessage.setCommunity(reqMsg, "public")
v2c.apiMessage.setPDU(reqMsg, reqPDU)
# noinspection PyUnusedLocal
def cbRecvFun(
transportDispatcher,
transportDomain,
transportAddress,
wholeMsg,
reqPDU=reqPDU,
headVars=headVars,
):
while wholeMsg:
rspMsg, wholeMsg = decoder.decode(wholeMsg, asn1Spec=v2c.Message())
rspPDU = v2c.apiMessage.getPDU(rspMsg)
# Match response to request
if v2c.apiBulkPDU.getRequestID(reqPDU) == v2c.apiBulkPDU.getRequestID(rspPDU):
# Format var-binds table
varBindTable = v2c.apiBulkPDU.getVarBindTable(reqPDU, rspPDU)
# Check for SNMP errors reported
errorStatus = v2c.apiBulkPDU.getErrorStatus(rspPDU)
if errorStatus and errorStatus != 2:
errorIndex = v2c.apiBulkPDU.getErrorIndex(rspPDU)
print(
"{} at {}".format(
errorStatus.prettyPrint(),
errorIndex and varBindTable[int(errorIndex) - 1] or "?",
)
)
transportDispatcher.jobFinished(1)
break
# Report SNMP table
for tableRow in varBindTable:
for name, val in tableRow:
print(
"from: {}, {} = {}".format(
transportAddress, name.prettyPrint(), val.prettyPrint()
)
)
# Stop on EOM
for oid, val in varBindTable[-1]:
if not isinstance(val, v2c.Null):
break
else:
transportDispatcher.jobFinished(1)
continue
# Generate request for next row
v2c.apiBulkPDU.setVarBinds(
reqPDU, [(x, v2c.null) for x, y in varBindTable[-1]]
)
v2c.apiBulkPDU.setRequestID(reqPDU, v2c.getNextRequestID())
transportDispatcher.sendMessage(
encoder.encode(reqMsg), transportDomain, transportAddress
)
return wholeMsg
transportDispatcher = AsyncioDispatcher()
transportDispatcher.registerRecvCbFun(cbRecvFun)
transportDispatcher.registerTransport(
udp.DOMAIN_NAME, udp.UdpAsyncioTransport().openClientMode()
)
transportDispatcher.sendMessage(
encoder.encode(reqMsg), udp.DOMAIN_NAME, ("demo.pysnmp.com", 161)
)
transportDispatcher.jobStarted(1)
# Dispatcher will finish as job#1 counter reaches zero
transportDispatcher.runDispatcher(3)
transportDispatcher.closeDispatcher()
Download
script.
See also: library reference.