[SNMP4J] UnknowHost Exception while sending the snmp trap
Frank Fock
fock at agentpp.com
Thu Mar 7 08:40:05 CET 2013
The format is probably wrong:
Address targetAddress =
GenericAddress.parse("udp:<HostName>:<TrapReceiverPort>/162");
Correct would be:
Address targetAddress =
GenericAddress.parse("udp:<HostName>/<TrapReceiverPort>");
Frank
Am 07.03.2013 01:18, schrieb Hallur,Parashuram:
> Frank:
> Could you please answer my follow up questions?
>
> I may attempt test program today my day time.
>
> Thanks,
> Parash
>
>
> On Wed, Mar 6, 2013 at 6:50 PM, Hallur,Parashuram <hallur.p.t at gmail.com>wrote:
>
>> Frank:
>> Thanks again for your response. I'm sorry if I was unclear.
>>
>> Let me add little more elaboration.
>>
>> 1. With snmp4j-1.0.jar : Application is bind to IPv6 socket address.
>> In this case trying to send the trap fails with the
>> java.nio.BufferOverFlowException is thrown.
>>
>> 2. With snmp4j-2.0.jar : Application is bind to all machine IP addresses.
>> Here the application is running/listening on dual stack mode.
>> In this case I get the "UnknownHostException" while parsing the target
>> address.
>>
>> 3. With snmp4j-2.0.jar : Application is bind to only IPv6 socket address.
>> The application is running/listening on IPv6 only address
>> In this case also, I get the "UnknownHostException" while parsing the
>> target address
>>
>> A question about the address parsing
>> This piece of code works for the application running on Ipv6 only, which
>> tries to send the trap?
>>
>> Address targetAddress =
>> GenericAddress.parse("udp:<HostName>:<TrapReceiverPort>/162");
>>
>>
>> I will make an attempt to write test program and let you know how it goes.
>>
>> Thanks,
>> Parash
>>
>>
>>
>> On Wed, Mar 6, 2013 at 6:35 PM, Frank Fock <frank.fock at t-online.de> wrote:
>>
>>> Hi Parash,
>>>
>>> The scenario with the three cases you described below does not make any
>>> sense to me.
>>> With "the application is bind to an address" you probably mean, the
>>> SNMP4J listen
>>> address. If so, this could not relate to the exception of case 1.
>>> Regarding case 2 and 3, seems to be simply a wrong target address and is
>>> unrelated to
>>> the local address SNMP4J is bound too.
>>>
>>> I think you should investigate this further and write a small - only
>>> SNMP4J based application
>>> that reproduces the error. I do not think that we can get any progress
>>> otherwise.
>>>
>>> Best regards,
>>> Frank
>>>
>>> Am 06.03.2013 09:27, schrieb Hallur,Parashuram:
>>>
>>> Reposting the complete thread with currect subject
>>> -------------------------------------------------------------------------
>>>
>>> Hi Frank:
>>>
>>> As I mentioned in my original email, the host is not getting recognized,
>>> it throws the "UnknownHostException" at the
>>> InetAddress.getByName("HostName"). The reason is the host name will be sent
>>> by snmp4j as "localhost:1622" to this underneath api, ideally it should not
>>> be sent with the trap receiver port. I tried this both for IPv4 and IPv6
>>> address application, in both cases I see the same issue with snmp4j-2.0.jar.
>>>
>>> My application is configurable to bind to particular address, it can be
>>> configured to bind to single socket address or multiple socket addresses.
>>>
>>> Following are the cases I tried
>>> 1. With snmp4j-1.0.jar : Application is bind to IPv6 socket address, the
>>> java.nio.BufferOverFlowException is thrown.
>>> 2. With snmp4j-2.0.jar : Application is bind to all machine IP addresses.
>>> "UnknownHostException" while parsing the target address
>>> 3. With snmp4j-2.0.jar : Application is bind to only IPv6 socket address.
>>> "UnknownHostException" while parsing the target address
>>>
>>> The code used to parse the address is -
>>>
>>> Address targetAddress =
>>> GenericAddress.parse("udp:<HostName>:<TrapReceiverPort>/162");
>>>
>>> Am I missing something here? Appreciate your help very much. Please let
>>> me know if you need more details.
>>>
>>> Thanks,
>>> Parash
>>>
>>> --------
>>>
>>> OK, that'a no problem. So then why do you get an exception?
>>>
>>> Am 06.03.2013 01:15, schrieb Hallur,Parashuram:
>>>
>>> --------
>>>
>>> Thank you so much for the response Frank.
>>>
>>> What do you exactly mean by "trap is bound to IPv6 address"?
>>>
>>> This means, the application which is running on IPv6 address is trying to
>>> send a notification to the trap receiver running on a dual stack IP ( both
>>> Ipv4 & IPv6 )mode machine.
>>>
>>> Thanks,
>>> Parash
>>>
>>> ----------
>>>
>>> Hi Parash,
>>>
>>> What do you exactly mean by "trap is bound to IPv6 address"?
>>>
>>> (If you tried to set the agentAddress field in a trap/notification with a
>>> IPv6 address
>>> you will fail, as SNMP supports IPv4 addresses only for this field.
>>>
>>> Best regards,
>>> Frank
>>>
>>> Am 06.03.2013 01:05, schrieb Hallur,Parashuram:
>>>
>>>
>>>
>>> On Wed, Mar 6, 2013 at 5:39 AM, Hallur,Parashuram <hallur.p.t at gmail.com>wrote:
>>>
>>>> Frank or any body else on the forum:
>>>>
>>>> Would you please help me with pointers on how to fix this issue? What
>>>> needs to be done to be able to send the traps from IPv6 application?
>>>> Thanks for any pointers.
>>>>
>>>> Parash
>>>>
>>>>
>>>> On Tue, Mar 5, 2013 at 7:24 AM, Hallur,Parashuram <hallur.p.t at gmail.com>wrote:
>>>>
>>>>> Thanks Frank for the response. Yes the application which is trying
>>>>> to send the trap is bound to IPv6 address, would you please help me with
>>>>> how to fix this issue?
>>>>>
>>>>> Thanks,
>>>>> Parash
>>>>>
>>>>>
>>>>> On Mon, Mar 4, 2013 at 11:44 PM, Frank Fock <fock at agentpp.com> wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I think you are trying to sent an IPv6 address as IpAddress BER encoded
>>>>>> on the wire. This is not possible, because the SNMP standard defines
>>>>>> IpAddress as IPv4 address and nothing else.
>>>>>> If this worked with 1.0 then this was an error in 1.0.
>>>>>>
>>>>>> Best regards,
>>>>>> Frank
>>>>>>
>>>>>> Am 04.03.2013 12:24, schrieb Hallur,Parashuram:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> I'm using the following code to create the target address.
>>>>>>>
>>>>>>> Address targetAddress =
>>>>>>> GenericAddress.parse("udp:<HostName>:<TrapReceiverPort>/162");
>>>>>>>
>>>>>>> This goes through fine when I use the snmp4j1.0.jar. However, this
>>>>>>> particular version seems does not support the IPv6 addresses. For IPv6
>>>>>>> requests it throws the java.nio.BufferOverFlowException.
>>>>>>> java.nio.BufferOverflowException
>>>>>>> at java.nio.Buffer.nextPutIndex(Unknown Source)
>>>>>>> at java.nio.HeapByteBuffer.put(Unknown Source)
>>>>>>> at org.snmp4j.asn1.BEROutputStream.write(BEROutputStream.java:65)
>>>>>>> at org.snmp4j.asn1.BER.encodeOID(BER.java:437)
>>>>>>> at org.snmp4j.smi.OID.encodeBER(OID.java:205)
>>>>>>> at
>>>>>>> org.snmp4j.smi.VariableBinding.encodeBER(VariableBinding.java:176)
>>>>>>> at org.snmp4j.PDUv1.encodeBER(PDUv1.java:207)
>>>>>>> at org.snmp4j.mp.MPv1.prepareOutgoingMessage(MPv1.java:108)
>>>>>>> at
>>>>>>>
>>>>>>> org.snmp4j.MessageDispatcherImpl.sendPdu(MessageDispatcherImpl.java:376)
>>>>>>> at org.snmp4j.Snmp.sendMessage(Snmp.java:900)
>>>>>>> at org.snmp4j.Snmp.send(Snmp.java:779)
>>>>>>> at org.snmp4j.Snmp.send(Snmp.java:771)
>>>>>>>
>>>>>>> To fix the above issue, I picked up the latest jars snmp4j2.1.0.jar,
>>>>>>> snmp4j1.11.3.jar, and snmp4j1.10.jar. All of these throw the unknown
>>>>>>> host
>>>>>>> exception. What I notice is that snm4j sends hostname as
>>>>>>> "hostname:trapreceiverport" to underneath java api to resolve the
>>>>>>> address,
>>>>>>> hence the issue unknownhostexception. The same code works with 1.0
>>>>>>> version
>>>>>>> of jar. Are there any difference from now and then? Any help is very
>>>>>>> much
>>>>>>> appreciated.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Parash
>>>>>>> _______________________________________________
>>>>>>> SNMP4J mailing list
>>>>>>> SNMP4J at 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 at agentpp.org
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>>>>>>
>>>>>
>>>
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