我有一个基于 pysnmp 的自定义 snmp 代理，我在端口 1161 上启动它，而且我还有自定义 MIB 文件。 我想检查它是否适用于 get 命令，但收到错误“超时：无响应”
my_snmp-agent.py
from pysnmp.hlapi import *
from pysnmp.entity import engine, config
from pysnmp.entity.rfc3413 import cmdrsp, context
from pysnmp import debug
from pysnmp.carrier.asyncore.dgram import udp
from pysnmp.smi import instrum, builder
from pysnmp.proto.api import v2c
import psutil
from pysnmp.smi import exval
# Create SNMP engine
snmpEngine = engine.SnmpEngine()
# Custom OIDs from MY-MIB
CPU_OID = '1.3.6.1.4.1.9999.2' # MY-MIB::cpuUtil
MEMORY_OID = '1.3.6.1.4.1.9999.1' # MY-MIB::memoryUtil
DISK_OID = '1.3.6.1.4.1.9999.3' # MY-MIB::diskUtil
def get_cpu_usage():
""" CPU usage percentage """
return int(psutil.cpu_percent(interval=1))
def get_memory_usage():
""" Memory usage percentage """
memory = psutil.virtual_memory()
return int(memory.used * 100 / memory.total)
def get_disk_usage():
""" Disk usage percentage: main partition """
disk = psutil.disk_usage('/')
return int(disk.used * 100 / disk.total)
def create_variable_binds(oid, value):
return [ObjectType(ObjectIdentity(oid), Integer32(value))]
def create_snmp_agent():
""" an SNMP agent listening for GET requests """
def process_snmp_request(snmpEngine, stateReference, contextEngineId, contextName, varBinds, cbCtx):
""" Processing SNMP GET requests """
oid, = [x[0] for x in varBinds]
oid_str = str(oid)
print("Received request for OID:", oid_str)
# Using appropriate response based on the OID
if oid_str.startswith(CPU_OID):
value = get_cpu_usage()
elif oid_str.startswith(MEMORY_OID):
value = get_memory_usage()
elif oid_str.startswith(DISK_OID):
value = get_disk_usage()
else:
value = 0 # Default response for unrecognized OIDs
# Creating and sending the response
varBinds = create_variable_binds(oid, value)
cmdrsp.sendVarBinds(snmpEngine, stateReference, contextEngineId, contextName, varBinds, cbCtx)
# Registering SNMP application
cmdrsp.GetCommandResponder(snmpEngine, CommunityData('public', mpModel=1))
# Processing SNMP GET requests
snmpContext = context.SnmpContext(snmpEngine)
snmpContext.registerContextName(v2c.OctetString('public'), process_snmp_request)
# Transport (UDP over IPv4)
config.addTransport(snmpEngine, udp.domainName, udp.UdpTransport().openServerMode(('127.0.0.1', 1161)))
print("SNMP Agent is running...")
snmpEngine.transportDispatcher.jobStarted(1)
try:
# Start dispatcher for receiving queries and sending responses
snmpEngine.transportDispatcher.runDispatcher()
except:
snmpEngine.transportDispatcher.closeDispatcher()
raise
if __name__ == "__main__":
create_snmp_agent()
我的MIB.txt
MY-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, Integer32
FROM SNMPv2-SMI;
myMIB MODULE-IDENTITY
LAST-UPDATED "202401260000Z"
ORGANIZATION "MyOrganization"
CONTACT-INFO "[email protected]"
DESCRIPTION "MIB for custom SNMP agent"
REVISION "202401260000Z"
DESCRIPTION "This custom version MIB"
::= { enterprises 9999 }
enterprises OBJECT IDENTIFIER ::= { iso(1) org(3) dod(6) internet(1) private(4) enterprises(1) }
memoryUtil OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION "Memory Utilization in percentage"
::= { myMIB 1 }
cpuUtil OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION "CPU Utilization in percentage"
::= { myMIB 2 }
diskUtil OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION "Disk Utilization in percentage"
::= { myMIB 3 }
END
编译成功。
smidump -k -f python -o my-mib.py MY-MIB.txt
在第一个航站楼启动我的代理：
python3 my_snmp-agent.py
SNMP Agent is running...
在第二个终端中使用 Net-SNMP 进行测试：
snmpget -v2c -c public 127.0.0.1:1161 1.3.6.1.4.1.9999.1
Timeout: No Response from 127.0.0.1:1161.
snmpwalk -v2c -c public 127.0.0.1:1161 1.3.6.1.4.1.9999
Timeout: No Response from 127.0.0.1:1161
snmpbulkget -v2c -c public 127.0.0.1:1161 1.3.6.1.4.1.9999.1 1.3.6.1.4.1.9999.2 1.3.6.1.4.1.9999.3
Timeout: No Response from 127.0.0.1:1161
在第二个终端中使用调试（-d）选项：
snmpget -v2c -c public -d 127.0.0.1:1161 1.3.6.1.4.1.9999.1
No log handling enabled - using stderr logging
Sending 43 bytes to UDP: [127.0.0.1]:1161->[0.0.0.0]:0
0000: 30 29 02 01 01 04 06 70 75 62 6C 69 63 A0 1C 02 0).....public?..
0016: 04 19 1E B4 74 02 01 00 02 01 00 30 0E 30 0C 06 ...?t......0.0..
0032: 08 2B 06 01 04 01 CE 0F 01 05 00 .+....?....
在第三个终端中启动 tcpdump：
tcpdump -i any port 1161 -vv
tcpdump: data link type PKTAP
tcpdump: listening on any, link-type PKTAP (Apple DLT_PKTAP), capture size 262144 bytes
19:20:30.761706 IP (tos 0x0, ttl 64, id 13838, offset 0, flags [none], proto UDP (17), length 71, bad cksum 0 (->4696)!)
localhost.49661 > localhost.health-polling: [bad udp cksum 0xfe46 -> 0x1ad6!] UDP, length 43
19:20:30.761729 IP (tos 0x0, ttl 64, id 13838, offset 0, flags [none], proto UDP (17), length 71, bad cksum 0 (->4696)!)
localhost.49661 > localhost.health-polling: [bad udp cksum 0xfe46 -> 0x1ad6!] UDP, length 43
19:20:31.766991 IP (tos 0x0, ttl 64, id 17114, offset 0, flags [none], proto UDP (17), length 71, bad cksum 0 (->39ca)!)