[SNMP4J] FW: Is it possible to create an OID in the agent (server) MIB from the manager (client)?
Frank Fock
fock at agentpp.com
Fri Oct 30 22:43:33 CET 2015
Hi Réda,
Please do not resend messages to the mailing list. Hundreds of people have to read your message once again! If someone could have answered your message, he or she would have done so. Resending probably reduces the change of a (quick) answer.
Regarding your question: You should use the TestAndIncr and the RowStatus textual conventions for your requirements.
Best regards,
Frank
> Am 30.10.2015 um 15:59 schrieb Réda BENKIRANE <reda.benkirane at hotmail.fr>:
>
>
>
> Réda BENKIRANE
>
> From: reda.benkirane at hotmail.fr
> To: fock at agentpp.com
> Subject: RE: [SNMP4J] Is it possible to create an OID in the agent (server) MIB from the manager (client)?
> Date: Thu, 29 Oct 2015 14:55:08 +0000
>
>
>
>
> Hi Frank,
> Thank you very much for your clear answer.
> I tried to gather what you told me and what I understood to continue building my Agent.
> What I want exactly is to create a conceptual table that has zero (or one "test" unuseful row) at the beginning and then, to be able to send a SET from the Manager. I want a structure of columns like that : { IPAddress IPAdd, Integer32 NodeID, Integer32 Counter }.
> => For IP Adresses that already exist in the MIB, I will simply increment the counter by sending a SET. => For IP Addresses that doesn't exist I want to CREATE a NEW row by sending a SET.
> Do you think that this is possible ? Particularly, what do you think is the best way to increment the counter ? I have thought about GET-ting the value and then SET-ting it but I don't know if this operation is safe (If another client thread tries to do the same thing at the same time).
> For what I have done till now, it unfortunately doesn't work. When I run the Agent, everything is okay, the conceptual table is created (Verified with an SNMP Walk on the root OID "1.3.6.1.2.1.3" using Paessler SNMP Tester 5.2.1).
> The problem occurs when I send the SET to the agent FROM the client (manager) (Please see the SET Implementation below).
> I get this error in the Agent Side :
> java.lang.Exception: Error 'Inconsistent naming used' generated at: 1.3.6.1.2.1.3.1 = 192.168.1.12 at org.snmp4j.agent.request.SnmpRequest$SnmpSubRequest.requestStatusChanged(SnmpRequest.java:621) at (...) at java.lang.Thread.run(Thread.java:745)
> I get this error in the Manager (Client) Side :
> java.io.IOException: Unexpected end of input stream at position 82 at org.snmp4j.asn1.BERInputStream.read(BERInputStream.java:58) at (...) at java.lang.Thread.run(Thread.java:745)
> Why it tries to write at "1.3.5.1.2.1.3.1" while I want it to write in a NEW row ? Here it would be "1.3.5.1.2.1.3.1.3"
> When I try to rather write at "1.3.5.1.2.1.3.x.3" (Non Existing Sub-OID) (x = 1, 2 or 3, depends on the column), I get this error (even if I have set ACCESS for the table to ACCESS_READ_CREATE) : Agent Side Error : java.lang.Exception: Error 'Not writable' generated at: 1.3.6.1.2.1.3.1.3 = 192.168.1.12 at org.snmp4j.agent.request.SnmpRequest$SnmpSubRequest.requestStatusChanged(SnmpRequest.java:621) at (...) at java.lang.Thread.run(Thread.java:745)Client Side Error : java.io.IOException: Unexpected end of input stream at position 85 at org.snmp4j.asn1.BERInputStream.read(BERInputStream.java:58) at (...) at java.lang.Thread.run(Thread.java:745)
> Even when I try to write at Existing-Row OID : "1.3.5.1.2.1.3.x.1", I get the same error ('Not Writeable').
> So, regarding all of this, how can I create a new row and increment the counter ? What did I do wrong ?
> Thank you very much for your help,
> Please see below the simplified implementations of my agent's main and addViews, and my client's main
> Reda
> PS : To understand, here are the implementations :
> Here is a simplified "Main" of my Agent :
> public static void main(String[] Args) {final OID customTable = new OID(".1.3.6.1.2.1.3");Agent agent = new Agent("172.24.167.61/161");agent.start();
> /* Here we create the conceptual table with ordered values in the MIB * "1.3.6.1.2.1.3.1.x" => 1st column * "1.3.6.1.2.1.3.2.x" => 2nd column * "1.3.6.1.2.1.3.3.x" => 3rd column*/MOTableBuilder customBuilder = new MOTableBuilder(customTable) .addColumnType(1, SMIConstants.SYNTAX_OCTET_STRING, MOAccessImpl.ACCESS_READ_CREATE) .addColumnType(2, SMIConstants.SYNTAX_INTEGER, MOAccessImpl.ACCESS_READ_CREATE) .addColumnType(3, SMIConstants.SYNTAX_INTEGER, MOAccessImpl.ACCESS_READ_CREATE) .addRowValue(new OctetString("192.168.1.10")) .addRowValue(new Integer32(0)) .addRowValue(new Integer32(100)) .addRowValue(new OctetString("192.168.1.11")) .addRowValue(new Integer32(0)) .addRowValue(new Integer32(200));
> agent.registerManagedObject(customBuilder.build());
> while(true) {
> System.out.println("Agent running...");
> Thread.sleep(5000);
> }}
> Here is the minimal view based Access Control method AddViews(VacmMIB vacm)
> /** * Minimal View based Access Control * * http://www.faqs.org/rfcs/rfc2575.html */ @Override protected void addViews(VacmMIB vacm) {
> vacm.addGroup(SecurityModel.SECURITY_MODEL_SNMPv2c, new OctetString( "cpublic"), new OctetString("v1v2group"), StorageType.nonVolatile);
> vacm.addAccess(new OctetString("v1v2group"), new OctetString("public"), SecurityModel.SECURITY_MODEL_ANY, SecurityLevel.NOAUTH_NOPRIV, MutableVACM.VACM_MATCH_EXACT, new OctetString("fullReadView"), new OctetString("fullWriteView"), new OctetString( "fullNotifyView"), StorageType.nonVolatile);
> vacm.addViewTreeFamily(new OctetString("fullReadView"), new OID("1.3"), new OctetString(), VacmMIB.vacmViewIncluded, StorageType.nonVolatile); vacm.addViewTreeFamily(new OctetString("fullWriteView"), new OID("1.3"), new OctetString(), VacmMIB.vacmViewIncluded, StorageType.nonVolatile); vacm.addViewTreeFamily(new OctetString("fullReadView"), new OID("1.3.6.1.2.1.3"), new OctetString(), VacmMIB.vacmViewIncluded, StorageType.nonVolatile); vacm.addViewTreeFamily(new OctetString("fullWriteView"), new OID("1.3.6.1.2.1.3"), new OctetString(), VacmMIB.vacmViewIncluded, StorageType.nonVolatile); }
> And finally here is the simplified "Main" of my SnmpSet Sample (Client) :
> private static String ipAddress = "172.24.167.61";private static String port = "161";
> /* * Root of the 1st column (OctetString IPAddress) : ".1.3.6.1.2.1.3.1" * Root of the 2nd column (Integer32 NodeID) : ".1.3.6.1.2.1.3.2" * Root of the 3rd column (Integer32 Counter) : ".1.3.6.1.2.1.3.3" */final static OID[] customTable = new OID[]{new OID(".1.3.6.1.2.1.3.1"), new OID(".1.3.6.1.2.1.3.2"), new OID(".1.3.6.1.2.1.3.3")}; private static int snmpVersion = SnmpConstants.version2c; private static String community = "public";
> public static void main(String[] args) throws Exception { TransportMapping transport = new DefaultUdpTransportMapping(); transport.listen(); CommunityTarget comtarget = new CommunityTarget(); comtarget.setCommunity(new OctetString(community)); comtarget.setVersion(snmpVersion); comtarget.setAddress(new UdpAddress(ipAddress + "/" + port)); comtarget.setRetries(2); comtarget.setTimeout(1500);
> /* Here we want to SEND a SET in order to CREATE a new ROW in the TABLE * customTable[0] => corresponds to the OID where to put the IP Address (here simply in OctetString format) * customTable[1] => corresponds to the OID where to put the Node-ID (I need a Node ID for my application) * customTable[2] => corresponds to the OID where to put the Counter (Here it is set to 125 but what I want finally * is to INCREMENT the counter, in order to have a Statistic). */PDU customTablePDU = new PDU(); customTablePDU.addAll(new VariableBinding[]{new VariableBinding(customTable[0],new OctetString("192.168.1.12")), new VariableBinding(customTable[1],new Integer32(0)), new VariableBinding(customTable[2],new Integer32(125))});customTablePDU.setType(PDU.SET);Snmp customSnmp = new Snmp(transport);
> System.out.println("Request:\nSending CustomTable Snmp Set Request to Agent (CREATE a new row)...");ResponseEvent customTableResponse = customSnmp.set(customTablePDU, comtarget);}
>
>
>
> Réda BENKIRANE
>
>> To: snmp4j at agentpp.org
>> From: fock at agentpp.com
>> Date: Thu, 22 Oct 2015 18:33:53 +0200
>> Subject: Re: [SNMP4J] Is it possible to create an OID in the agent (server) MIB from the manager (client)?
>>
>> Hi Réda,
>>
>> If you have the MIB specification, the steps to do are (for a production
>> grade system):
>>
>> 1. Write or generate using AgenPro, the ManagedObject implementations
>> for the MIB specification.
>> 2. Instrument the ManagedObjects (i.e., MOScalars and MOMutableTableRows).
>> 3. Compile the agent and run it
>> 4. Set variable binding you want to change.
>> 5. The agent instrumentation code will be called and can then act upon
>> the new value.
>>
>> As a consequence from the above, you will not be able to create totally
>> new MIB objects in an agent.
>> Means, MIB object instances for MIB object definitions, that the authors
>> of the agent did not implement.
>>
>> However, the SNMP standard allows to define SNMP tables. Tables can
>> contain zero rows. To create
>> a new row, typically using the RowStatus column of that table, you
>> simple SET the RowStatus column
>> of the new row to createAndWait(5). You will have to define/find out a
>> valid row index (the row "name")
>> for the new row. That row index OID is then appended to the OID of the
>> column you SET.
>>
>> With the above approach you are able to create "new" objects in an
>> agent, the agent did not had before.
>> However, the structure of those objectzs must be already known at
>> compile time to the agent.
>>
>> All the above, is true for product grade agents.
>>
>> If you want to simulate an agent and simply provide/put data in an agent
>> without implementing any
>> functionality based on that data, then you can also create totally new
>> object VBs at runtime.
>> The AgenPro built-in simulation agent does that by dynamically load new
>> MIB specifications.
>> You can use the SimMOFactory by implementing the AgentppSimulationMib in
>> your agent, for instance.
>>
>> Hope this helps.
>>
>> Best regards,
>> Frank
>>
>>> Am 22.10.2015 um 17:27 schrieb Réda BENKIRANE:
>>> I am using SNMP4J Framework and it implements and makes possible the standard SET, GET, GET-NEXT, etc. messages.For example, with a SET, I can update the value of the MIB OID "1.3.6.1.2.50.0". This works perfectly for me. I can do that using org.snmp4j.Snmp.set(PDU pdu, Target target)What I want to do now is to CREATE a custom MIB OID (as "1.3.6.1.2.100.0") FROM the client and assign a value to it and not simply update an existing MIB OID value.Is there any standard SNMP way to do that easily ?
>>> Réda BENKIRANE
>>> _______________________________________________
>>> SNMP4J mailing list
>>> SNMP4J at agentpp.org
>>> https://oosnmp.net/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 at agentpp.org
>> https://oosnmp.net/mailman/listinfo/snmp4j
>
> _______________________________________________
> SNMP4J mailing list
> SNMP4J at agentpp.org
> https://oosnmp.net/mailman/listinfo/snmp4j
More information about the SNMP4J
mailing list