> Frank, > > Thank you for the response. I tried a few more experiments this > morning. I ruled out problem #1 (access rights) as I was able to do > gets and sets with a MIB browser application using the same > credentials. That pointed me to problem #2. > > I found that if I read, then write things work every time. I'm > attaching (does this work?) Wireshark captures of a scenario where GET, > then SET, then GET again. This results in four message pairs being > sent, namely: > > 1a. Generic GET message > 1b. Unknown engine response (1.3.6.1.6.3.15.1.1.4) > > 2a. First GET message. I noted that neither authoritative engine > boots nor authoritative engine time are set on this outbound message. > 2b. First GET response. > > 3a. SET message. Here, the engine boots and engine time are set > properly. > 3b. SET response. > > 4a. Second GET message. Here, again, the engine boots and engine time > are set properly. > 4b. Second GET response. > > My working theory is that in my original example, the first message was > a SET without the time set properly. In this latest experiment, I > think I worked around it by doing a GET first. > > Thanks for the pointers, > > Peter > > -----Original Message----- > From: snmp4j-boun...@agentpp.org [mailto:snmp4j-boun...@agentpp.org] On > Behalf Of Frank Fock > Sent: Wednesday, September 04, 2013 17:51 > To: snmp4j@agentpp.org > Subject: Re: [SNMP4J] Difficulty with SNMP v3 Set > > Hello Peter, > > There could be two different reasons for your observation: > > 1. The agent uses different access rights for SET and GET PDUs which > the user you are using does not equally have on the device. > 2. The engine time synchronization fails for some reason. > > For the second case, using the latest SNMP4J version could help if the > device (or the sender) has a very weak internal clock. > > The engine time can only be put in the sending request, if there was > already some communication with the agent. > If you create a new Snmp instance for each request then this happens > all the time. Thus, you should reuse a single Snmp instance for all the > communication. > > Best regards, > Frank > > > Am 04.09.2013 19:46, schrieb McCarthy, Peter CIV NAWCTSD, 4.6.2.3: > > Hello all, > > > > I'm having difficulty with sending SNMP v3 sets to a secured (MD5/DES > > such as it is) power strip. Code (largely taken from the get example > > in the documentation) is at the bottom: > > > > If I uncomment the GET STUFF section and comment out the SET STUFF > > section, everything works and all the correct data is returned. > > > > If I uncomment the SET STUFF section and comment out the GET STUFF > > section, no errors are returned. However, the setting is not placed > > on the device (verified through the device's web interface). > > > > When I used Wireshark, I noticed on when a set message is sent, > > neither the authoritative time nor boot count is placed in the > > outgoing set request. > > > > Message flow, per Wireshark, looks like > > > > (1) Outbound, generic set or get message > > (2) Inbound, 1.3.6.1.6.3.15.1.1.4 (unknown engine) > > (3) Outbound, some encrypted PDU > > (4) Inbound, response PDU > > > > Occasionally (rarely), there is another pair of messages between (2) > > and (3), namely: > > > > (2a) Outbound, some encrypted PDU > > (2b) Inbound, 1.3.6.1.6.3.15.1.1.2 (not in time window) > > > > If the "not in time window" appears, message (3) above will have > > authoritative time and boot count populated. > > > > Am I doing something wrong here? > > > > Thanks, > > > > Peter... > > > > Address targetAddress = > > GenericAddress.parse("udp:192.168.1.107/161"); > > TransportMapping transport = new > DefaultUdpTransportMapping(); > > Snmp snmp = new Snmp(transport); > > MPv3 mpv3 = > > (MPv3) > > snmp.getMessageProcessingModel(MessageProcessingModel.MPv3); > > USM usm = new USM(SecurityProtocols.getInstance(), > > new OctetString(mpv3.createLocalEngineID()), 0); > > System.err.println("Enabled? " + > > usm.isEngineDiscoveryEnabled()); > > SecurityModels.getInstance().addSecurityModel(usm); > > transport.listen(); > > > > // add user to the USM > > snmp.getUSM().addUser(new OctetString("usernamehere"), > > new UsmUser(new OctetString("usernamehere"), > > AuthMD5.ID, > > new OctetString("passwordhere"), > > PrivDES.ID, > > new OctetString("passwordhere"))); > > // create the target > > UserTarget target = new UserTarget(); > > target.setAddress(targetAddress); > > target.setRetries(1); > > target.setTimeout(5000); > > target.setVersion(SnmpConstants.version3); > > target.setSecurityLevel(SecurityLevel.AUTH_PRIV); > > target.setSecurityName(new OctetString("usernamehere ")); > > > > > > // GET STUFF > > // PDU pdu = new ScopedPDU(); > > // pdu.add(new VariableBinding(new > > OID("1.3.6.1.4.1.318.1.1.12.1.2.0"))); > > // pdu.add(new VariableBinding(new > > OID("1.3.6.1.4.1.318.1.1.12.1.3.0"))); > > // pdu.add(new VariableBinding(new > > OID("1.3.6.1.4.1.318.1.1.12.1.5.0"))); > > // pdu.add(new VariableBinding(new > > OID("1.3.6.1.4.1.318.1.1.12.1.1.0"))); > > // pdu.add(new VariableBinding(new > > OID("1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.2"))); > > // pdu.add(new VariableBinding(new > > OID("1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.3"))); > > // pdu.add(new VariableBinding(new > > OID("1.3.6.1.4.1.318.1.1.12.3.4.1.1.4.2"))); > > // pdu.setType(PDU.GET); > > > > // SET STUFF > > PDU pdu = new ScopedPDU(); > > OID o1 = new OID("1.3.6.1.4.1.318.1.1.12.3.4.1.1.4.2"); > > Integer32 i32 = new Integer32(32); > > pdu.add(new VariableBinding(o1, i32)); > > pdu.setType(PDU.SET); > > > > // send the PDU > > ResponseEvent response = snmp.send(pdu, target); > > // extract the response PDU (could be null if timed out) > > PDU responsePDU = response.getResponse(); > > System.err.println("Error status: " + > > responsePDU.getErrorStatus()); > > if(responsePDU != null) { > > for (VariableBinding b : > > responsePDU.getVariableBindings()) > > { > > System.err.println(b.toString()); > > > > } > > } > > _______________________________________________ > > SNMP4J mailing list > > SNMP4J@agentpp.org > > http://lists.agentpp.org/mailman/listinfo/snmp4j > > -- > --- > AGENT++ > Maximilian-Kolbe-Str. 10 > 73257 Koengen, Germany > https://agentpp.com > Phone: +49 7024 8688230 > Fax: +49 7024 8688231 > > _______________________________________________ > SNMP4J mailing list > SNMP4J@agentpp.org > http://lists.agentpp.org/mailman/listinfo/snmp4j
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