Agent-Side MIB Implementations#
import sys
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdrsp, context
from pysnmp.carrier.asyncio.dgram import udp
from pysnmp.proto.api import v2c
# Create SNMP engine
snmpEngine = engine.SnmpEngine()
# Transport setup
# UDP over IPv4
config.addTransport(
snmpEngine, udp.DOMAIN_NAME, udp.UdpTransport().openServerMode(("127.0.0.1", 161))
)
# SNMPv2c setup
# SecurityName <-> CommunityName mapping.
config.addV1System(snmpEngine, "my-area", "public")
# Allow read MIB access for this user / securityModels at VACM
config.addVacmUser(snmpEngine, 2, "my-area", "noAuthNoPriv", (1, 3, 6, 5))
# Create an SNMP context
snmpContext = context.SnmpContext(snmpEngine)
# --- create custom Managed Object Instance ---
mibBuilder = snmpContext.getMibInstrum().getMibBuilder()
MibScalar, MibScalarInstance = mibBuilder.importSymbols(
"SNMPv2-SMI", "MibScalar", "MibScalarInstance"
)
class MyStaticMibScalarInstance(MibScalarInstance):
# noinspection PyUnusedLocal,PyUnusedLocal
def getValue(self, name, idx):
return self.getSyntax().clone(
f"Python {sys.version} running on a {sys.platform} platform"
)
mibBuilder.exportSymbols(
"__MY_MIB",
MibScalar((1, 3, 6, 5, 1), v2c.OctetString()),
MyStaticMibScalarInstance((1, 3, 6, 5, 1), (0,), v2c.OctetString()),
)
# --- end of Managed Object Instance initialization ----
# Register SNMP Applications at the SNMP engine for particular SNMP context
cmdrsp.GetCommandResponder(snmpEngine, snmpContext)
cmdrsp.NextCommandResponder(snmpEngine, snmpContext)
cmdrsp.BulkCommandResponder(snmpEngine, snmpContext)
# Register an imaginary never-ending job to keep I/O dispatcher running forever
snmpEngine.transportDispatcher.jobStarted(1)
# Run I/O dispatcher which would receive queries and send responses
try:
snmpEngine.openDispatcher()
except:
snmpEngine.closeDispatcher()
raise
Download
script.
Implementing conceptual table#
Listen and respond to SNMP GET/SET/GETNEXT/GETBULK queries with the following options:
SNMPv2c
with SNMP community “public”
define a simple SNMP Table within a newly created EXAMPLE-MIB
pre-populate SNMP Table with a single row of values
allow read access only to the subtree where example SNMP Table resides
over IPv4/UDP, listening at 127.0.0.1:161
The following Net-SNMP commands will populate and walk a table:
…while the following command will destroy the same row
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdrsp, context
from pysnmp.carrier.asyncio.dgram import udp
from pysnmp.proto.api import v2c
# Create SNMP engine
snmpEngine = engine.SnmpEngine()
# Transport setup
# UDP over IPv4
config.addTransport(
snmpEngine, udp.DOMAIN_NAME, udp.UdpTransport().openServerMode(("127.0.0.1", 161))
)
# SNMPv2c setup
# SecurityName <-> CommunityName mapping.
config.addV1System(snmpEngine, "my-area", "public")
# Allow read MIB access for this user / securityModels at VACM
config.addVacmUser(snmpEngine, 2, "my-area", "noAuthNoPriv", (1, 3, 6, 6), (1, 3, 6, 6))
# Create an SNMP context
snmpContext = context.SnmpContext(snmpEngine)
# --- define custom SNMP Table within a newly defined EXAMPLE-MIB ---
mibBuilder = snmpContext.getMibInstrum().getMibBuilder()
(MibTable, MibTableRow, MibTableColumn, MibScalarInstance) = mibBuilder.importSymbols(
"SNMPv2-SMI", "MibTable", "MibTableRow", "MibTableColumn", "MibScalarInstance"
)
(RowStatus,) = mibBuilder.importSymbols("SNMPv2-TC", "RowStatus")
mibBuilder.exportSymbols(
"__EXAMPLE-MIB",
# table object
exampleTable=MibTable((1, 3, 6, 6, 1)).setMaxAccess("read-create"),
# table row object, also carries references to table indices
exampleTableEntry=MibTableRow((1, 3, 6, 6, 1, 5))
.setMaxAccess("read-create")
.setIndexNames((0, "__EXAMPLE-MIB", "exampleTableColumn1")),
# table column: string index
exampleTableColumn1=MibTableColumn(
(1, 3, 6, 6, 1, 5, 1), v2c.OctetString()
).setMaxAccess("read-create"),
# table column: string value
exampleTableColumn2=MibTableColumn(
(1, 3, 6, 6, 1, 5, 2), v2c.OctetString()
).setMaxAccess("read-create"),
# table column: integer value with default
exampleTableColumn3=MibTableColumn(
(1, 3, 6, 6, 1, 5, 3), v2c.Integer32(123)
).setMaxAccess("read-create"),
# table column: row status
exampleTableStatus=MibTableColumn(
(1, 3, 6, 6, 1, 5, 4), RowStatus("notExists")
).setMaxAccess("read-create"),
)
# --- end of custom SNMP table definition, empty table now exists ---
# --- populate custom SNMP table with one row ---
(
exampleTableEntry,
exampleTableColumn2,
exampleTableColumn3,
exampleTableStatus,
) = mibBuilder.importSymbols(
"__EXAMPLE-MIB",
"exampleTableEntry",
"exampleTableColumn2",
"exampleTableColumn3",
"exampleTableStatus",
)
rowInstanceId = exampleTableEntry.getInstIdFromIndices("example record one")
mibInstrumentation = snmpContext.getMibInstrum()
mibInstrumentation.writeVars(
(exampleTableColumn2.name + rowInstanceId, "my string value"),
(exampleTableColumn3.name + rowInstanceId, 123456),
(exampleTableStatus.name + rowInstanceId, "createAndGo"),
)
# --- end of SNMP table population ---
# 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
snmpEngine.transportDispatcher.jobStarted(1)
# Run I/O dispatcher which would receive queries and send responses
try:
snmpEngine.openDispatcher()
except:
snmpEngine.closeDispatcher()
raise
Download
script.
Serve non-default MIB tree#
Listen and respond to SNMP GET/SET/GETNEXT/GETBULK queries with the following options:
SNMPv3
with USM username usr-md5-none
using alternative set of Managed Objects addressed by contextEngineId: 8000000001020304, contextName: my-context
allow access to SNMPv2-MIB objects (1.3.6.1.2.1)
over IPv4/UDP, listening at 127.0.0.1:161
Either of the following Net-SNMP commands will walk this Agent:
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdrsp, context
from pysnmp.carrier.asyncio.dgram import udp
from pysnmp.smi import instrum, builder
from pysnmp.proto.api import v2c
# Create SNMP engine
snmpEngine = engine.SnmpEngine()
# Transport setup
# UDP over IPv4
config.addTransport(
snmpEngine, udp.DOMAIN_NAME, udp.UdpTransport().openServerMode(("127.0.0.1", 161))
)
# SNMPv3/USM setup
# user: usr-md5-none, auth: MD5, priv NONE
config.addV3User(snmpEngine, "usr-md5-none", config.USM_AUTH_HMAC96_MD5, "authkey1")
# Allow full MIB access for each user at VACM
config.addVacmUser(
snmpEngine, 3, "usr-md5-none", "authNoPriv", (1, 3, 6, 1, 2, 1), (1, 3, 6, 1, 2, 1)
)
# Create an SNMP context with ContextEngineId = 8000000001020304
snmpContext = context.SnmpContext(
snmpEngine, contextEngineId=v2c.OctetString(hexValue="8000000001020304")
)
# Create an [empty] set of Managed Objects (MibBuilder), pass it to
# Management Instrumentation Controller and register at SNMP Context
# under ContextName 'my-context'
snmpContext.registerContextName(
v2c.OctetString("my-context"), # Context Name
instrum.MibInstrumController(builder.MibBuilder()), # Managed Objects
)
# 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
snmpEngine.transportDispatcher.jobStarted(1)
# Run I/O dispatcher which would receive queries and send responses
try:
snmpEngine.openDispatcher()
except:
snmpEngine.closeDispatcher()
raise
Download
script.
Multiple MIB trees under distinct context names#
Listen and respond to SNMP GET/SET/GETNEXT/GETBULK queries with the following options:
SNMPv3
with USM username usr-md5-none
using two independent (empty) sets of Managed Objects addressed by SNMP context name context-a and context-b
allow access to SNMPv2-MIB objects (1.3.6.1.2.1)
over IPv4/UDP, listening at 127.0.0.1:161
Either of the following Net-SNMP commands will walk this Agent:
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdrsp, context
from pysnmp.carrier.asyncio.dgram import udp
from pysnmp.smi import instrum, builder
from pysnmp.proto.api import v2c
# Create SNMP engine
snmpEngine = engine.SnmpEngine()
# Transport setup
# UDP over IPv4
config.addTransport(
snmpEngine, udp.domainName, udp.UdpTransport().openServerMode(("127.0.0.1", 161))
)
# SNMPv3/USM setup
# user: usr-md5-none, auth: MD5, priv NONE
config.addV3User(snmpEngine, "usr-md5-none", config.USM_AUTH_HMAC96_MD5, "authkey1")
# Allow full MIB access for each user at VACM
config.addVacmUser(
snmpEngine, 3, "usr-md5-none", "authNoPriv", (1, 3, 6, 1, 2, 1), (1, 3, 6, 1, 2, 1)
)
# Create an SNMP context with default ContextEngineId (same as SNMP engine ID)
snmpContext = context.SnmpContext(snmpEngine)
# Create multiple independent trees of MIB managed objects (empty so far)
mibTreeA = instrum.MibInstrumController(builder.MibBuilder())
mibTreeB = instrum.MibInstrumController(builder.MibBuilder())
# Register MIB trees at distinct SNMP Context names
snmpContext.registerContextName(v2c.OctetString("context-a"), mibTreeA)
snmpContext.registerContextName(v2c.OctetString("context-b"), mibTreeB)
# 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
snmpEngine.transportDispatcher.jobStarted(1)
# Run I/O dispatcher which would receive queries and send responses
try:
snmpEngine.openDispatcher()
except:
snmpEngine.closeDispatcher()
raise
Download
script.
Custom MIB Controller#
Listen and respond to SNMP GET/SET/GETNEXT/GETBULK queries with the following options:
SNMPv3
with USM username usr-none-none
using alternative set of Managed Objects addressed by contextName: my-context
allow access to SNMPv2-MIB objects (1.3.6.1.2.1)
over IPv4/UDP, listening at 127.0.0.1:161
The following Net-SNMP command will send GET request to this Agent:
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdrsp, context
from pysnmp.carrier.asyncio.dgram import udp
from pysnmp.smi import instrum
from pysnmp.proto.api import v2c
# Create SNMP engine
snmpEngine = engine.SnmpEngine()
# Transport setup
# UDP over IPv4
config.addTransport(
snmpEngine, udp.DOMAIN_NAME, udp.UdpTransport().openServerMode(("127.0.0.1", 161))
)
# SNMPv3/USM setup
# user: usr-none-none, auth: NONE, priv NONE
config.addV3User(snmpEngine, "usr-none-none")
# Allow full MIB access for each user at VACM
config.addVacmUser(
snmpEngine,
3,
"usr-none-none",
"noAuthNoPriv",
(1, 3, 6, 1, 2, 1),
(1, 3, 6, 1, 2, 1),
)
# Create an SNMP context
snmpContext = context.SnmpContext(snmpEngine)
# Very basic Management Instrumentation Controller without
# any Managed Objects attached. It supports only GET's and
# always echos request var-binds in response.
class EchoMibInstrumController(instrum.AbstractMibInstrumController):
def readVars(self, *varBinds, **context):
return [
(ov[0], v2c.OctetString("You queried OID %s" % ov[0])) for ov in varBinds
]
# Create a custom Management Instrumentation Controller and register at
# SNMP Context under ContextName 'my-context'
snmpContext.registerContextName(
v2c.OctetString("my-context"), # Context Name
EchoMibInstrumController(), # Management Instrumentation
)
# Register GET&SET Applications at the SNMP engine for a custom SNMP context
cmdrsp.GetCommandResponder(snmpEngine, snmpContext)
cmdrsp.SetCommandResponder(snmpEngine, snmpContext)
# Register an imaginary never-ending job to keep I/O dispatcher running forever
snmpEngine.transportDispatcher.jobStarted(1)
# Run I/O dispatcher which would receive queries and send responses
try:
snmpEngine.openDispatcher()
except:
snmpEngine.closeDispatcher()
raise
Download
script.
See also: library reference.