[SNMP4J] Problem with SNMP Receiver

[Adam Brons]

I realized my last paragraph was a but difficult to understand so I'll 
state what's going on a bit better here (I hope).

I'm using the snmp4j command-line tool to send snmp messages to my SNMP 
Trap receiver.  I'm doing all of this on a local box. During this process 
I'm running tcpdump for port 16200 (above 1024 for testing).  I see the 
tcp 3-way handshake and some data being pushed to the SNMP Trap receiver, 
but what I don't see is any indication that my 
CommandResponder.processPdu() was called.

Here's the CommandLine I'm using to send SNMP Packets:
        ./SNMP4J-linux -p TRAP -v 1 tcp:127.0.0.1/16200

Also while my SNMP Trap receiver is running I see see listening ports for 
16200 for both tcp and udp via a "netstat -an" command.  I'm event able to 
telnet to the tcp port 16200 and get connected.

I've looked a numerous examples on the mailing list, the SnmpRequest, and 
the Snmp class itself for using the addNotificationListener and still seem 
to be running up against a brick wall.
Oh and to point out the obvious... Yes my logging does work.  All log 
messages are reported except for the ones in "processPdu()".

Any help would be most appreciated.





Adam Brons/Atlanta/IBM at IBMUS 
Sent by: snmp4j-bounces at agentpp.org
03/28/07 08:22 PM

To
snmp4j at agentpp.org
cc

Subject
[SNMP4J] Problem  with SNMP Receiver






Hey Everyone, I'm trying to put together a SNMP Trap receiver and I am 
having some trouble with the CommandResponder.  I'm hoping you guys can 
point out what I'm doing wrong.

Thanks - in advance:

public class SNMPListener {
        // Number of SNMP Dispatcher Threads
        private static final int DISPATHER_THREAD_NUMBER = 2;
        private static Logger logger = 
Logger.getLogger(SNMPListener.class);
        private Snmp snmp = null;
        private USM usm = null;
 
        private InetAddress bindAddress;
        private Integer port;
        private Collection users;
 
        protected SNMPListener() throws UnknownHostException {
                this("0.0.0.0", 162, null);
        }
 
        protected SNMPListener(String bindAddress, Integer port, 
Collection users) throws UnknownHostException {
                this.bindAddress = InetAddress.getByName(bindAddress);
                this.port = port;
                this.users = users;
 
                // Create a thread pool to handle inbound SNMP events
                ThreadPool threadPool = ThreadPool.create("SNMPTrap", 
DISPATHER_THREAD_NUMBER);
                MessageDispatcher mtDispatcher = 
                        new MultiThreadedMessageDispatcher(threadPool, new 

MessageDispatcherImpl());
 
                // Add the SNMP versions we wish to monitor for
                mtDispatcher.addMessageProcessingModel(new MPv1());
                mtDispatcher.addMessageProcessingModel(new MPv2c());
                mtDispatcher.addMessageProcessingModel(new MPv3());
 
                snmp = new Snmp(mtDispatcher);
 
                // Setup Authentication and Encryption protocols for 
SNMPv3
                SecurityProtocols.getInstance().addDefaultProtocols();
 
            usm = new USM(SecurityProtocols.getInstance(),
                new OctetString(MPv3.createLocalEngineID()), 0);
            SecurityModels.getInstance().addSecurityModel(usm);
        }
 
        public synchronized void listen() throws IOException {
                // Make a tcp and udp based address for listening
                UdpAddress udpAddr = new UdpAddress(bindAddress,port);
                TcpAddress tcpAddr = new TcpAddress(bindAddress,port);
                SNMPEventDispatcher dispatcher = new 
SNMPEventDispatcher();
 
                // Add transport mapping and command handler to Snmp 
Engine
                if (snmp.addNotificationListener(udpAddr, dispatcher) &&
                        snmp.addNotificationListener(tcpAddr, dispatcher)) 

{
 
                        // Start listening
                        snmp.listen();
                        logger.info("Listening on 
UDP:"+udpAddr.toString()+"...");
                        logger.info("Listening on 
TCP:"+tcpAddr.toString()+"...");
 
                        // Just wait for something to happen.
                        try { this.wait(); }
                    catch (InterruptedException ex) { } 
                } else {
                        logger.error("Unable to bind 
address("+udpAddr.toString()+") to snmp listener");
                }
        }
 
        public static void main(String[] args) throws Exception {
                SNMPListener listener = new SNMPListener();
                listener.listen();
        }
}

public class SNMPEventDispatcher implements CommandResponder, 
AuthenticationFailureListener {
        private static Logger logger = 
Logger.getLogger(SNMPEventDispatcher.class);
 
        public SNMPEventDispatcher() {
                logger.debug("Instaniated SNMPEventDispatcher");
        }
        public synchronized void processPdu(CommandResponderEvent event) {
                logger.debug("ProcessPdu called for event 
["+event.toString()+"]");
                if (event.isProcessed()) {
                        logger.debug("Snmp Event ["+event.toString()+"] 
processed.");
                        return;
                }
 
                PDU pdu = event.getPDU();
                logger.debug("Received PDU: "+ pdu.toString());
 
                // This must be set when an CommandResponderEvent has been 

processed.
                event.setProcessed(true);
        }
 
        public void authenticationFailure(AuthenticationFailureEvent 
event) {
                logger.warn("Inbound SNMP event failed authentication");
        }
}


What's not happening is even with tcpdump traces and using tcp to show two 

way communication I never see logging from 
SNMPEventDispather.processPdu(CommandResponderEvent event).
As an added tidbit I'm running this in a JUNIT test in Eclipse so I don't 
know if that has anything to do with it.

Adam
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