Knowledge Base

• SNMP Related
• JDK Related

SNMP Related

1. SnmpSession.open has been known to hang with JIT in jdk1.1.7 on Windows systems and in jdk1.1.6 and 1.1.7 of Solaris. This is due to problem with the JIT. Either upgrade the JVM to a later release or please use older versions. This is because of the native threads problem in Solaris 2.5.1. Please take a look at the following URLs from Sun Microsystems for more information.
   http://java.sun.com/products/jdk/1.2/install-solaris-patches.html
   http://splash.javasoft.com/products/jdk/1.1/packs/native-threads/README

2. Even after killing rmipoller in rmiAppletDemo the polling thread in rmiserver is not cleaned up.

3. CORBA examples cause a segmentation fault on the SNMP server side on Solaris 2.6 with JDK 1.2.

4. While adding multiple clients to the SnmpSession the debugPrint() method of all the clients are invoked with the debug messages. This causes irrelevant debug messages sent to other clients.

5. In the MibBrowser, BarGraph will not plot multiple values at a time.

6. While using the EJB examples available in the ejbclient directory, the client applications must set the classpath to AdventNet EJB classes and AdventNetSnmp.jar before setting it to the Application Servers classes.

7. The help icon in the MibBrowser bean will launch a web browser and try to load the help files from the installed directory of the package. If the MibBrowser bean is tested outside the package the help icon will not invoke the help files. Method setHelpURL() of the MibBrowser bean can be made use of for specifying the proper location.

8. If the session used by the MibBrowser is used by some other bean, then the MibBrowser debug window will display PDU dumps of requests sent by other beans.

9. Database support (for SNMPv3 user information) is not provided for async_create_v3_tables() in the high level API.

10. In RMI after receiving the TrapEvent instance if the client invokes the getTrapDefinition() method then the return value will always be null.

11. Features like database support for loading MIBs, storing v3 security parameters etc., are not available with the HTTPMibBrowser.

12. RMI requests will be slow in Windows NT and Windows 2000 machines. This is because, the RMI Registry does a DNS lookup for the hostname specified.

13. There are some incompatibility issues in WebLogic 6.0 Application Server with respect to standard stubs and skeletons. The WebLogic 6.0 does not support the standard stub and skeleton classes i.e. it looks for weblogic specific stub and skeleton classes. The weblogic specific stub and skeleton classes have SomeClass_WLStub.class and SomeClass_WLSkel.class format. Therefore, if we run the startup class 'SnmpStarter' inside the WebLogic Server it may not succeed.

14. When the same SnmpPDU is sent continuously say after changing some fields like remote host or remote port, the user has to take care of the requestID that needs to be set on the SnmpPDU. Otherwise, every request will be sent with the requestID generated first.

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JDK Issues

Policy files are one way of specifying permissions for RMI in the new security model. To do this create a file containing the following.

grant permission java.net.SocketPermission "*:1024-65535", 
permission java.net.SocketPermission "*:80","connect";

For example if you name this file as SnmpRmi.policy, then you have to run snmp_rmiserver as given below.

java -Djava.security.policy=SnmpRmi.policy
com.adventnet.snmp.rmi.SnmpFactoryImpl

The other issue is related to applets. The appletviewer no longer takes the classpath setting into consideration. So, for some of the applets such as the requestServerDemo the command to be given is 

appletviewer -J-Xbootclasspath:.;..\..\classes;
c:\jdk1.2\jre\lib\rt.jar requestServerDemo.html

Applets could instead be packaged into jar files for easy use in browsers. Also with JDK1.2 you can specify dependencies on other jars through extensions. Therefore, if you create an applet that uses AdventNet beans and the target platform is the JDK1.2-plugin, then just add a line including the CLASSPATH. The manifest for your jar will look something like the following.

Manifest-Version: 1.0 Class-Path: AdventNetSnmp.jar

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