AdventNet MibBrowser Overview

Introduction

SNMP MibBrowsers allow the user to view and operate on data available through an SNMP agent on a managed device, e.g. a router. In order to enable a better view of the data available on the SNMP agent a MIB file is usually provided with the managed device. This MIB file contains a description of the object hierarchy on the managed device, as well as the syntax and access privileges for each variable in the MIB.

The AdventNet MibBrowser provides the capability to load and view multiple MIB modules, and traverse the MIB tree to look at the definitions for each node in the MIB tree. It allows "GET", "GETNEXT", "GETBULK" and "SET" SNMP requests to a particular variable in the MIB of an SNMP managed device. In case of Snmp Version V1, GETBULK is not available. It also provides the capability to view multiple real-time graphs of data on the managed device as it changes over time. It also enables viewing SNMP tables.

The AdventNet MibBrowser can be used either as an application or as an applet. In both of them there are certain operations available.

MibBrowser Primary Display

The primary window of the MibBrowser includes a MIB tree to select the nodes , fields for SNMP agent name or address (Host), community, writeCommunity, value used for a set request and the current Node OID that's being operated upon the current MIB module ,a text area to view query results, checkboxes to select multiple request, a list to add and delete the varbinds and the buttons to add and delete the varbinds from the list. User can show/hide the Toolbar, Mib Description panel, Muti varbind panel and Result display panel.

The operations allowed with the MibBrowser are available through the series of buttons at the top of the MibBrowser's main window. Click the buttons to peform the operations.User can hide the Toolbar by deselecting the ToolBar item in the view menu. Menu Bar is also available for doing all the operations.

ToolBar
ToolBar can be customized. User can add and remove the buttons from the Toolbar. You need to add a little bit of code to the MibBrowserApplication.java or MibBrowserApplet.java. An Exit button is added to MibBrowser application example to show how to add a button to the ToolBar. Similarly you can add your own buttons and actions to them.

Loading MIBs and Unloading the MIBs

The MibBrowser has a LOAD MIB image button or select Load menu item. This brings up a dialog which prompts you for the URL of the MIB module file you wish to load .

For MibBrowser used as an applet, the relative URL has to be specified but for the MibBrowser used as an application you can specify the absolute or relative URL. For MibBrowser applet this may not work if you're trying to read a MIB module on some host that's not the applet host because of browser security.

You can load multiple modules and choose any one of them as the current module at any time. When any MIB module is selected, the root node for that module becomes the current OID.

The loading of MIB modules is via URLs. A few MIB modules are provided with the AdventNet MibBrowser , i.e. RFC1213-MIB, RFC1271-RMON, RFC1155-SMI, RMON2-MIB, TOKEN-RING-RMON-MIB and RFC1315-FRAME. But you can choose to load any other MIB modules. It may be convenient to copy your MIB module files to be loaded into the "mibs" directory.

To unload the loaded MIB select the node of the MIB Tree then click on the UNLOAD MIB image button or select UnLoad menu item. This will remove the MIB Tree of the MIB unloaded. To unload all the MIBs select UnLoadAllMIBS menu item or click on the UNLOAD MIB image button without selecting any node of the MIB Tree.

To view the description of a node select a mib tree node and click on the DESCRIBE image button or select Describe menu item. . This will pop up a window showing the description of that node.

Getting and Setting SNMP Variables

To fully specify an object to an SNMP agent, both the Object ID (which defines the type of object) and the instance (the specific object of the given type) need to be provided. From the MIB you get the Object ID, to which an instance needs to be added to completely identify the object of interest. For non-tabular (or scalar) objects this is simply an instance of 0 (e.g. sysDescr.0)(this need not be specified). For tabular objects the instance is defined by the MIB, and is a sequence of one or more variables (e.g. ifInOctets.2 or tcpConnState.179.74.15.126.1192.225.226.126.197.80).

In order to graph and set SNMP variables, you will need to completely specify the Object ID plus instance. However, you can use getnext, and specify just the Object ID from the MIB (e.g. sysDescr), and get the first instance of that type from the SNMP agent. This works for all types of objects.

Select a MIB node of interest to you, and either select getnext, or add the instance you're interested in at the end of the OID and use get. Once you have the correct instance, you can graph it and use set as well. You will also need to specify the hostname and community string of the SNMP agent you're talking to in the appropriate field.

If you want to talk to a V3 agent, then you have to choose the Version3 from the choice box in the Settings dialog and also make sure that the v3 parameters are set in V3 Settings Dialog .

Multi-Varbind Request

Select the Multi-Varbind menu item from the View menu to view the Multi varbind panel. To do a multiple varbind request select the leaf node and append the instance and click on the Add button. It will add the OID given in the Object Identifier field and theValue given in the SetValue field both seperated with a colon to the list. If value is not given in the SetValue field then NULL value is appended. You can add multiple number of OIDs and Values like this. Make sure you have enabled the Multi-var check-box before doing a SNMP operation for multiple varbind SNMP request. Otherwise it will do a request for the OID in the Object Identifer field. To do multiple variable SNMP SET ensure the OID and the proper value is given in the textfield before adding to the list. Enable the Multi-Var check-box before doing the multiple variable SET.

To delete the varbind(s) from the list select the varbind(s) from the list and click on the Delete button to delete the varbind(s) from the list.

To Edit the varbinds added in the list select a varbind and click on the Edit button. It will show an OID and the Value of the varbind in the TextFields of the ObjectID and the SetValue. Edit it and press OK button to modify the OID and Value or press the Cancel button to restore the old values .

To do a GET operation click on the GET image button or select Get menu item. This will get all objects under the selected MIB object, or the specific object if the MIB node and instance are specified.

To do a GETNEXT operation click on the GETNEXT image button or select GetNext menu item. This will get the next object after the specified object, or the specific object instance if a MIB node is specified.

To do a GETBULK operation click on the GETBULK image button or select GetBulk menu item. This will get a sequence of Next Objects immediately after the specified object. The number of Object instances returned is equal to the Max-Repetitions field.

To do a SET operation click on the SET image button or select Set menu item.This enables setting the value of the specified object, based on the value in the Set Value field. To do a SET for Octet String Type in hex format enter the bytes in hex format with each bytes seperated by a colon and the entire string within single quotes. For example to give 0xff0a3212 enter 'ff:0a:32:12' in the SetValue field.

MibBrowser Settings

To set the values for port, version, timeout and retries click on the SETTINGS image button or select Settings menu item. This will bring up a dialog where the Snmp Port, Trap Port, Snmp Version, Timeout, Retries etc. are to be specified. The default values for port, version, timeout and retries are 161, v1, 5 sec and 0 respectively.

There is an option provided to enable serialization of V3Tables, UserEntry and EngineEntry. If this is choosen, then the users added will be serialized in the files UserEntry.ser and EngineEntry.ser. The next time the mibBrowser is started, v3 tables will be deserialized if the serialize V3Tables is true. Also there is an option to serialize the MibModule and load the mibs from the serialized file. The load time is reduced by 40% if mibs is loaded from a serialized file. If the serialize MibModule is choosen and the Save as option is enabled,the user can specify the file name for serialization. If no file name is specified in the SaveAs option, then the file name for serialization will be the Mib name + "ser". For e.g. If the Mib file is RFC1213-MIB then the defalut file name for serialization is RFC1213-MIB.ser. In case of applets the serialize MibModule option is disabled. If the Load mibs from serialized file is choosen, then the serialized mibs can be loaded from the load mibs option. If a mib to be serialized imports other mibs, then all the mibs are serialized in a single file.

To set the v3 parameters click on the v3Settings TAB. This has the v3 parameters UserName, AuthProtocol, AuthPassword and PrivPassword. Options are provided to add, delete and select users.

Trap Browser

TrapBrowser is newly added to the MibBrowser. Using this you can view the incoming traps to the specified port. TrapPort
field is provided to set the port to listen for traps in the MibBrowser settings or in the TrapBrowser. TrapBrowser creates a file
called new_trap_parser.parser when you start. By default it will receive all the traps. You can edit/add properties to this file to
filter the incoming traps.

Viewing Real-time Graphs

Before using the Graph button, the agent hostname or IP address and a valid OID need to be specified. The OID needs to be an integer or unsigned integer (Counter, Gauge or Timeticks) and include the instance being graphed. If you're browsing the MIB tree, ensure you get the required instance by using the GET NEXT button, before clicking on graph. You can bring up multiple graphs showing different variables from different hosts.

To view the graph click on the GRAPH image button or select the menu item Line Graph or Bar Graph from the View menu. This brings up an automatically updated graph showing the results of periodically polling the specified agent for the specified OID. The polling for the graph is done every 5 seconds. Options like Average over Interval, Show Absolute Time, Polling Interval, Range etc. are added to the Graph.

Snmp Table

To view the SNMP Table click on the SNMP TABLE image button . This brings up an SnmpTable if the selected OID is a table. In the SnmpTable, clicking on the "Start" button will start getting the columnar objects.

Help and Debugging Output

To see the debug output click on the DEBUG image button or select Debug menu item. It will brings up a window. As long as this window is opened, debugging is turned on, and debugging output is generated. When you close this window debugging is turned off.

To clear the TextArea click on the CLEAR image button or select Clear menu item. It clears the QUERY RESULTS , which sometimes overflows it's capacity and needs to be cleared.

To stop the polling click on the STOP image button or select Stop menu item. It is used to stop an SNMP walk initiated with a GET.

To see the on-line help of AdventNet MibBrowser click on the HELP button or select Help menu item. This will bring up this help window.

Starting the MibBrowser

To fully use the AdventNet MibBrowser V1/V2c/V3 , you will need the Java Development Kit (JDK) from Sun Microsystems or a Java enabled browser like Netscape, and run in one of the following configurations.

All needed class files local to your machine which means downloading the AdventNet SNMPV1/V2c/V3 Package and MibBrowser V1/V2c/V3 (you could use any Java enabled browser or the JDK appletviewer you need to be setup properly). The CLASSPATH should include your Java classes.zip (either the JDK or your browser version) and ...\adventSnmpVxxx\classes (not ...\adventSnmpVxxx\classes\Snmp). Do one of the following:

Copy the directories in the AdventNet supplied classes dir into your web browsers java classes directory, e.g. \windows\java\classes for Explorer 3.0.

Set your CLASSPATH to include the AdventNet supplied classes dir in a shell window (or DOS window), and start appletviewer or your browser from that same shell window.

This gives you the best performance, particularly with the JDK appletviewer.

Network loading the classes from your web server. Needs JDK on your web server and a Java enabled browser like Netscape. You would need to run a Java application provided by us (SAS) on your web server to provide a passthrough for the MibBrowser V1/V2c/V3 applet to talk to your managed device. The only other way is to disable security, which can be done for appletviewer for example. See the setup section of the tutorial for details.

Run as an Application.

Problems?

We'd like to get reports on any problems you're having using the browser. We'd suggest you to check the FAQ and other documentation first, and then send in a problem report to us at snmp-support@adventnet.com if you do not find a solution in the documentation. Please include as much information as you have on the problem. We will endeavor to get back to you with an answer. The java-nm mailing list would be another good resource for getting any problems resolved.

Common Problems :

Netscape / IE reports:

# Error Sending PDUSecurity Exception connecting to remote host.

Cause :

Applets are not allowed to talk to any host apart from the web server from which they were downloaded. The alternative is to use the SAServer while running the browser.