Pysnmp Trap Receiver.for SNMPv3問題

Question

PSNMP Socket實際上正在接收陷阱，但回調函數沒有被調用。我已啓用調試日誌記錄。使用Pysnmp 4.3.3

from pysnmp.entity import engine, config 
from pysnmp.carrier.asyncore.dgram import udp 
from pysnmp.entity.rfc3413 import ntfrcv 
from pysnmp.proto.api import v2c 
from pysnmp.smi import builder, view, compiler, rfc1902, error 
from pysnmp import debug 

debug.setLogger(debug.Debug('all')) 
snmpEngine = engine.SnmpEngine() 

config.addTransport(
    snmpEngine, 
    udp.domainName, 
    udp.UdpTransport().openServerMode(('0.0.0.0', 1036)) 
) 

config.addV3User(
    snmpEngine, 'user_snmp1234' 
) 

def cbFun(snmpEngine, stateReference, contextEngineId, contextName, 
      varBinds, cbCtx): 
    print "#######################Recived Notification from {} #######################".format(snmpEngine.msgAndPduDsp.getTransportInfo(stateReference)[-1][0]) 
    for oid, val in varBinds: 
     output = rfc1902.ObjectType(rfc1902.ObjectIdentity(oid), 
             val).resolveWithMib(mibViewController).prettyPrint() 
     print output 

ntfrcv.NotificationReceiver(snmpEngine, cbFun) 
snmpEngine.transportDispatcher.jobStarted(1) 
try: 
    snmpEngine.transportDispatcher.runDispatcher() 
except: 
    snmpEngine.transportDispatcher.closeDispatcher() 
    raise 

我可以看到它的reciving v3的陷阱：

2017-02-24 00:46:02,853 pysnmp: prepareDataElements: SNMPv3Message: 
msgVersion=3 
msgGlobalData=HeaderData: 
    msgID=16259 
    msgMaxSize=65535 
    msgFlags=0x00 
    msgSecurityModel=3 

msgSecurityParameters=0x3027040c80000f150000000000000000020100020100040d757365725f736e6d703132333404000400 
msgData=ScopedPduData: 
    plaintext=ScopedPDU: 
    contextEngineId=0x80000f150000000000000000 
    contextName= 
    data=PDUs: 
    snmpV2-trap=SNMPv2TrapPDU: 
    request-id=775985686 
    error-status='noError' 
    error-index=0 
    variable-bindings=VarBindList: 
     VarBind: 
     name=1.3.6.1.2.1.1.3.0 
     =_BindValue: 
     value=ObjectSyntax: 
     application-wide=ApplicationSyntax: 
      timeticks-value=10000 

但最後我選通的一些錯誤是這樣的：

2017-02-24 00:46:02,853 pysnmp: prepareDataElements: msg data msgVersion 3 msgID 16259 securityModel 3 
2017-02-24 00:46:02,854 pysnmp: processIncomingMsg: securityParameters 
00000: 30 27 04 0C 80 00 0F 15 00 00 00 00 00 00 00 00 
00016: 02 01 00 02 01 00 04 0D 75 73 65 72 5F 73 6E 6D 
00032: 70 31 32 33 34 04 00 04 00 
2017-02-24 00:46:02,854 pysnmp: processIncomingMsg: UsmSecurityParameters: 
msgAuthoritativeEngineId=0x80000f150000000000000000 
msgAuthoritativeEngineBoots=0 
msgAuthoritativeEngineTime=0 
msgUserName=user_snmp1234 
msgAuthenticationParameters= 
msgPrivacyParameters= 

2017-02-24 00:46:02,855 pysnmp: processIncomingMsg: cache write securityStateReference 6156330 by msgUserName user_snmp1234 
2017-02-24 00:46:02,855 pysnmp: processIncomingMsg: unsynchronized securityEngineID OctetString(hexValue='80000f150000000000000000') 
2017-02-24 00:46:02,855 pysnmp: processIncomingMsg: read from securityParams msgAuthoritativeEngineId OctetString(hexValue='80000f150000000000000000') msgUserName OctetString('user_snmp1234', subtypeSpec=ConstraintsIntersection(ConstraintsIntersection(), ValueSizeConstraint(0, 32))) 
2017-02-24 00:46:02,855 pysnmp: processIncomingMsg: unknown securityEngineID OctetString(hexValue='80000f150000000000000000') msgUserName OctetString('user_snmp1234', subtypeSpec=ConstraintsIntersection(ConstraintsIntersection(), ValueSizeConstraint(0, 32))) 
2017-02-24 00:46:02,855 pysnmp: StatusInformation: {'securityLevel': 1, 'contextName': '', 'val': Counter32(3), 'contextEngineId': SnmpEngineID(), 'oid': (1, 3, 6, 1, 6, 3, 15, 1, 1, 3, 0), 'maxSizeResponseScopedPDU': 65446, 'securityStateReference': 6156330, 'errorIndication': <pysnmp.proto.errind.UnknownSecurityName object at 0x7f1c3d7cf910>} 
2017-02-24 00:46:02,855 pysnmp: prepareDataElements: SM failed, statusInformation {'securityLevel': 1, 'contextName': '', 'val': Counter32(3), 'contextEngineId': SnmpEngineID(), 'oid': (1, 3, 6, 1, 6, 3, 15, 1, 1, 3, 0), 'maxSizeResponseScopedPDU': 65446, 'securityStateReference': 6156330, 'errorIndication': <pysnmp.proto.errind.UnknownSecurityName object at 0x7f1c3d7cf910>} 
2017-02-24 00:46:02,855 pysnmp: returnResponsePdu: PDU <empty> 
2017-02-24 00:46:02,855 pysnmp: prepareResponseMessage: stateReference 9434948 
2017-02-24 00:46:02,856 pysnmp: StatusInformation: {'errorIndication': <pysnmp.proto.errind.LoopTerminated object at 0x7f1c3d7cf290>} 
2017-02-24 00:46:02,856 pysnmp: prepareDataElements: error reported 

Answer 1

SNMPv3 TRAP mandate您將TRAP發送應用程序的SNMP引擎ID配置爲TRAP接收用於每個USM用戶應用：

config.addV3User(
    snmpEngine, 'user_snmp1234', 
    securityEngineId=v2c.OctetString(hexValue='8000000001020304') 
) 

所以，你應該要麼配置（或在設備配置弄清楚）你的TRAP發送的應用或設備的權威SNMP引擎ID，然後將它們配置到您的TRAP接收機。

如果您正在努力確定設備的SNMP引擎ID，請嘗試this tool - 它會與您的設備通信並報告其SNMP引擎ID。

這是怎麼了，你可以發送帶有的Net-SNMP SNMPTRAP工具TRAP其SNMP引擎ID設置爲特定值：

$ snmptrap -v3 -u user_snmp1234 -l noAuthNoPriv -e 8000000001020304 127.0.0.1 123 1.3.6.1.6.3.1.1.5.1 

隨着第一環節，所有的併發症是由於這樣的事實解釋（否則自動）SNMP引擎ID發現不會超過單向消息，如TRAP。