[SNMP4J] Setting Local port in DefaultUdpTransport causes null responses.

[Giuseppe Sarno]

Hello,
one of the reason is because I would like agents to reply to this specific port (Firewall etc.)

Thanks.

-----Original Message-----
From: snmp4j-bounces at agentpp.org [mailto:snmp4j-bounces at agentpp.org] On Behalf Of Frank Fock
Sent: 02 March 2011 22:30
To: snmp4j at agentpp.org
Subject: Re: [SNMP4J] Setting Local port in DefaultUdpTransport causes null responses.

Hi,

You need to close the transport in order to be able to bind the port again.
The OS might block a rebind for several
seconds/minutes.

What are you trying to test/show with
the code?

Why do you want to specify a specific
local port? (I do not recommend that
for several reasons)

Best regards,
Frank

On 02.03.2011 23:21, Giuseppe Sarno wrote:
> Hello,
> new to SNMP and to this API.
> I am trying to use code snippet from http://www.snmp4j.org/doc/org/snmp4j/Snmp.html to build a SNMP manager that sends a SET between 2 nodes (SNMP4J 1.11.2).
> I use Java executors to invoke the task that will actually perform the work. I noticed that this works ok if I don't set the LocalPort in the UDP transport.
> I actually would like to fix the port to a specific value so I set it in the transport constructor. Unfortunately after this change the PDU response is always "null".
> Messages are correctly sent and replied back (checked with wireshark). I am not too sure whether there is any threading issue as the transport is bound to a specific port or simply my code is not correct.
>
> Can anybody please let me know if there is any problem with this approach and what the problme could be ?
>
> Thanks.
>
>
> The task will:
>
> 1)  Creates DefaultUdpTransportMapping (note I need to set the local 
> port and I to add to set the option "reuse" to true as I was getting 
> bind exception)
>
> 	DefaultUdpTransportMapping(new 
> UdpAddress(InetAddress.getLocalHost(),localport),true);
>
> 2)  Creates community target.
>
>      	CommunityTarget comtarget = new CommunityTarget();
>      	comtarget.setCommunity(new OctetString(community));
>      	comtarget.setVersion(snmpVersion);
>     	comtarget.setAddress(new UdpAddress(ip + "/" + port));
>      	comtarget.setRetries(0);
>     	 comtarget.setTimeout(100);
>
> 3)  Creates a PDU
>
>        PDU pdu = new PDU();
>
> 4) Creates SNMP with the UDP transport (above)
>
> 	Snmp snmp = new Snmp(this.getUDPTransport());
>
> 5) Sends and wait for the resposne:
>
> 	ResponseEvent response = snmp.set(pdu, comtarget);
> 	// Process Agent Response
> 	if (response != null)
> 	{
>     		>>  do work<<
> 	}
>
> Excecutor that wraps the code above:
>
> ExecutorService threadExecutor = Executors.newFixedThreadPool( 
> Data.POOL ); for ( int i=1;i<=100000;i++) {
>   RunnableTask t = new RunnableTask(Integer.toString(i));
>   threadExecutor.execute(t);
> }
>   threadExecutor.shutdown(); // shutdown worker threads } 
> _______________________________________________
> SNMP4J mailing list
> SNMP4J at agentpp.org
> http://lists.agentpp.org/mailman/listinfo/snmp4j

-- 
AGENT++
http://www.agentpp.com
http://www.snmp4j.com
http://www.mibexplorer.com
http://www.mibdesigner.com

_______________________________________________
SNMP4J mailing list
SNMP4J at agentpp.org
http://lists.agentpp.org/mailman/listinfo/snmp4j