[SNMP4J] V3 traps failing when multiple senders exist.

[david jones]

I was trying to test code that receives traps from 2 different senders
using the same security name, but different passwords.  One senders PDUs
are parsed correctly, the others are not (mostly  1.3.6.1.6.3.15.1.1.5.0 =
0 (wrong digest)).   I assume i have to do an addUser() for each different
password, what else is needed? do i also need to set the engineID for each
addUser?

I tried some scaffolding code that created a UserTarget for each sender's
IP and then did " discoverAuthoritativeEngineID(userTarget.getAddress(),
5000)", with intent of adding the found engineID to the addUser but the
results were empty, but is that on the right track? Or is there something
(unique engineIDs?) senders aren't generating correctly?

I then tried getting rid of the multiple users and try it with just one
addUser and all senders using the same password: Still only one of the
senders PDUs are successfully read, the others are rejected, now
with 1.3.6.1.6.3.15.1.1.5.2.0 = 0 (not in time window). Is this still the
same underlying cause, or do i need to reboot the receivers and senders to
resynch or ??

I also noticed the warnings messages that indicate errors all have *oid = *0.
Isn't the = n value supposed to be incrementing, not always 0?

Below is a code snipet:

transport = new DefaultUdpTransportMapping(new
UdpAddress(ServerProperties.getSnmpTrapPort()));  // using private port,
not 161/162
 MessageDispatcher mtDispatcher = new MessageDispatcherImpl();
 // add message processing models
 mtDispatcher.addMessageProcessingModel(new MPv1());
 mtDispatcher.addMessageProcessingModel(new MPv2c());
 mtDispatcher.addMessageProcessingModel(new MPv3());
 // add all security protocols
 SecurityProtocols.getInstance().addDefaultProtocols();

 snmp = new Snmp(mtDispatcher, transport);


 if (version == SnmpConstants.version3) {
     usm = new USM(SecurityProtocols.getInstance(), engineID, 0);
     SecurityModels.getInstance().addSecurityModel(usm);


     snmp.setLocalEngine(engineID.getValue(), 0, 0);

     // Add some predefined users

     snmp.getUSM ().addUser (
new OctetString ("mytrap"),
new UsmUser (
new OctetString ("mytrap"), AuthMD5.ID,
        new OctetString ("AAAAAAAA"),null,null);

     snmp.getUSM ().addUser (
new OctetString ("mytrap"),
   new UsmUser (
new OctetString ("mytrap"), AuthMD5.ID,
new OctetString ("BBBBBBBB"),null,null);

 }
snmp.addCommandResponder(this);
transport.listen();

-- 
David
jonesda24 at gmail.com