[SNMP4J] UnknowHost Exception while sending the snmp trap
Hallur,Parashuram
hallur.p.t at gmail.com
Thu Mar 7 12:45:07 CET 2013
Thanks much Frank.
Here is the behavior with the jar snm4j-2.0.jar
I changed the parsing code as you suggested -
Address targetAddress =
GenericAddress.parse("udp:<HostName>/<TrapReceiverPort>");
Good news is now this works fine if the trap sending application is bind to
dual stack addresses. However it does not work if the application is bind
only to IPv6 address. No exception/error message is generated and there is
no trap received at the receiver side. Is there a modification required for
IPv6 only address application to be able to send the trap?
Also, just out of the curiosity, with the snm4j-1.0.jar, the following code
to parse the address use to work perfect for IPv4 & IPv6
Address targetAddress =
GenericAddress.parse("udp:<HostName>:<TrapReceiverPort>/162");
Does this mean, there is a changing in the parsing logic from now and then?
Thanks again,
Parash
On Thu, Mar 7, 2013 at 1:10 PM, Frank Fock <fock at agentpp.com> wrote:
> 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
>>>>>>>> ______________________________**_________________
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>>>>>>>> SNMP4J at agentpp.org
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>>>>>>>>
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>>>>>>> 73257 Koengen, Germany
>>>>>>> https://agentpp.com
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>>>>>>> Fax: +49 7024 8688231
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>>>>>>>
>>>>>>
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