7.0 Testing the Agent

 

7.1 Overview
7.2 Starting MIB Browser
7.3 Using MIB Browser

7.4 Testing the Agent with SNMP Operations

7.5 Using Row Status

 

7.1 Overview

 

This section explains the various kinds of SNMP operations that can be performed on the Agent for Testing purposes. SNMP Operations include SNMP GET, GET-NEXT, SET, WALK, GET-BULK, and so on. Let us see in detail how these have to be used on the Agent. It is assumed that a v2c Agent is created using AGENT-SAMPLE-MIB following the steps given in Creating a Simple Agent using MIB Compiler section.

 

7.2 Starting MIB Browser

 

An SNMP Manager environment is created using the MIB Browser tool.  Please follow the steps given below to start the MIB Browser application and configure the Manager settings.

  1. To start this tool, use MIBBrowser.bat or .sh file in <Agent Toolkit Home>/bin directory.

  2. Load the MIB e.g, AGENT-SAMPLE-MIB for which an SNMP Agent is created.

  3. Click the Settings sub menu in the Edit menu bar.

  4. A wizard opens up with a General Tab open.

  5. Check the version, v2c (for our case).

  6. And click OK.

  7. The Manager's Port can be specified in the field given for Port in the MIB Browser main UI.

7.3 Using MIB Browser

 

The WebNMS MIB Browser can be used for MIB browsing and to view and operate on data available through a SNMP agent. The MIB Browser can be configured in tune with performing the SNMP operations.

In order to configure the MIB Browser,

On performing any of the above action, a dialog box opens which is the MIB Browser settings frame that has three-tabbed panel. The three tabs are

Now, let us have an overview on the configuration of the MIB Browser under various tabs.

This topic also covers Graphs and Debugging and Decoding of Messages.

 

7.3.1 Setting Common Parameters

 

The common parameters are set in the General tab of the MIB Browser Settings frame. The General field. The figure depicted below shows the General Settings in the MIB Browser.

 

             

             

The various protocol-related options to SNMP are listed in the table below.

    Options Default Values Other Options

    Snmp Version

    v1

    v2c or v3

    Time out

    5 sec

    any user defined value

    Retries

    0

    any user defined value

    Encoding

    ISO8859_1

    any encoding scheme that
    supports text format

    Max repetitions

    50

    any user defined value

    Non-repeaters

    0

    any user defined value

     

    Note:

    • Timeout is the time interval that an application waits for a response message from an agent before timing out. Retries is the number of times a request is sent when a timeout occurs. If the retry value is 0, the request is re-transmitted on timeout.

    • The options Max-repetitions and Non-repeaters are enabled only when the SNMP version is set to either v2c or v3. This is because, the GETBULK operation is available only in v2c and v3. A GETBULK request is performed by giving an OID along with two other parameters, Max Repetitions value and Non Repeaters value.

    • Encoding, in general, means, modifying information into the required transmission format. Computers around the world store information using a variety of encoding schemes. Net MIB Browser support the ISO8859_1, which means ISO 8859_1, Latin alphabet No.1. There are various other encoding schemes that support various text formats. You can use the encoding scheme that best suits your requirement while performing SNMP operations. To view the encoding scheme that is supported by Java Development Kit, see: http://java.sun.com/products/jdk/1.1/docs/guide/intl/encoding.doc.html.

     

    The Validate Broadcast Address check box enables you to check the validity of the broadcast address provided. You need to provide the Netmask address to validate the broadcast address. A Netmask is a string of 0's and 1's that hides the network part of the IP address and allows only the host ID to remain.

    In the v3 Options section, Context Name and the ContextID are to be provided as additional parameters for an SNMPv3 request. An SNMP context name is a collection of management information accessible by an SNMP entity. An item of management information may exist in more than one context. An SNMP entity potentially has access to many contexts. In other words, if a management information has been defined under certain context by an SNMPv3 entity, any management application can access that information by giving that context name. The ContextID uniquely identifies an SNMP entity that may recognize an instance of a context with a particular context name within an administrative domain.

    The next section is the v3Settings section. The following are the security-related parameters for accessing the SNMPv3 agents. You can add, modify, and delete users by clicking the Add, Modify, Delete buttons.

     

    Options Default Values Other Options

    User name

    null

    any user-defined value

    Security level

    noAuth noPriv

    Auth noPriv and Auth Priv

    Authentication Protocol

    MD5 (if authentication is
    chosen in security level)

    SHA

    Privacy Protocol

    CBC-DES (if privacy is
    chosen in security level) 

    not available

    Authentication password

    any user defined value

    -

    Privacy password

    any user defined value

    -

    Target host

    localhost

    any host with SNMPV3 agent or proxy agent

    Target port

    161

    any user-defined port

If the security level is "NoAuthNoPriv", no additional parameters are required. If the security level is "AuthNoPriv", the parameters AuthProtocol and AuthPassword are be set. If the user security level is "AuthPriv", the privacy password needs to be set in addition to the other parameters.

The v3Settings section has an option for storing the v3 table entries. The v3 table entries can be stored in:

Storing table entries in a serialized file

 

To enable serialization of v3 table entries, select the Save v3 Settings to File option. If this option is selected, the user information is stored in the serialized files namely UserEntry.ser and EngineEntry.ser. When MIB Browser is invoked the next time, the serialized files are de-serialized and the v3 table is updated. The advantage of storing table entries in serialized files is that the operation is faster.

 

Storing table entries in a database

 

To store v3 table entries in a database, select the Save v3 Settings to Database option. To use this, the database connection has to be established. Clicking the "Database Settings" button displays the Database Parameters dialog box. The image of the dialog box that appears is given below.

Enter the necessary database parameters in this dialog box, and click the OK button. If the database connection is established successfully, all the user information entered is saved in the database. When the MIB Browser is invoked the next time, v3 details are restored and the v3 table is updated.

The advantages of storing v3 table entries in a database are:

The last section is the field entry section in which the corresponding fields in the v3 table are displayed for data entry. The various buttons available in the field entry section are the Add, Modify, and Delete buttons.

To add an entry, enter the required parameters in the respective fields and click the Add Entry button. Based on the parameters and the security level, Discovery and Time Synchronization are done and USM Table is updated and listed in the v3 table. 

To modify an entry, select the entry in the v3 table, modify the required fields, and click the Modify button. Time Synchronization is done and the USM table is updated and listed in the v3 table.

    Note: The NoAuthNoPriv entry cannot be modified. Only the password fields in the AuthNoPriv entry and AuthPriv entry can be modified.

To delete an entry in the v3 table, select the entry in the v3 table and click the Delete button. The entry is removed from the USM table.

    Note: The settings are saved only on exiting the MIB Browser application and not every time the settings are modified. The 'Save v3 Settings to File' option is enabled only in the MIB Browser application and not in the MIB Browser applet because of certain security restrictions in applets.

7.3.2 Setting MIB Parameters

 

The Mib Settings tab is focused on the loading of MIBs in MIB Browser. The image below displays the Mib Settings tab.

 

 

The first section gives the MIB loading options. The next section displays the various parsing levels.

 

7.3.2.1 MIB Loading Options

 

The various Options available for Loading the MIB are:

    Note: "Load MIBs From Compiled File" is by default selected when a MIB Browser is used as an Application. In case of MIB Browser used as an Applet, the default option selected is "Load MIBs directly".

7.3.2.1.1 Load MIBs directly

 

The MIB file is usually read and parsed into MIB modules and displayed in the MIB tree. In this case, when you load a MIB file, it is parsed and then loaded. This is time consuming because parsing is done every time a MIB file is loaded.

 

7.3.2.1.2  Load MIBs From Compiled Files

 

The next option is loading of the MIB files as compiled files. The main advantage here is that the loading time is reduced. This ultimately leads to the improvement in performance. To store the MIB information in a formatted structure, the following two new file types are made available.

When the option Load MIBs from Compiled File is selected, the MIB Browser loads the MIB from the cmi and cds files. If these files are not present, MIB Browser parses the MIB file, writes the output in the cmi and cds files, and loads the MIB file. For example, if we load the RFC1213-MIB, the MIB file is parsed and stored in the compiled MIB files as RFC1213-MIB.cmi and RFC1213-MIB.cds provided RFC1213-MIB is the module name of the RFC1213-MIB file.

When this MIB file is loaded again, the MIB is loaded from the cmi and cds files and no parsing is done. The advantage of using this option is, we need not parse the MIB each time we load, thus optimizing the load time and improving the performance. While loading the compiled MIBs, we need to only load the cmi file. The cmi file has a reference to the cds files. Therefore, the cds file need not be loaded directly.

    Note: Any changes made to the MIB file after it has been loaded as a compiled MIB file, are not reflected when it is loaded again. You have to remove the existing cmi and cds files and load the MIB again to get the latest changes shown. To overcome this, select the option" Overwrite existing Compiled MIB Files" can be selected. If this option is set to true, the cmi and cds files are created each time the MIB is loaded. However, enabling this option is recommended only if you have changed the contents of the MIB file. Otherwise, this serves as a redundant option and increase the load time of the MIBs.

7.3.2.1.3 Loading MIB's from database

 

The third option is loading of the MIB files from a database. The MIB files can be stored in any RDBMS such as MySql or Oracle. Applications can load these MIB files directly from the database. This feature is particularly useful when the number of MIB files to be loaded is high in number.

The MIB Browser uses JDBC (Java Database Connectivity) for the database support. Applications should use a valid JDBC driver of the respective databases to enable the database support. 

Selecting the option Load MIBs from Database enables the text fields in the JDBCParams section. On initializing the necessary database parameters in this section, the database support can be provided for loading MIBs. The various JDBCParams required are:

After selecting this loading option, select the required MIB file to be loaded from the Open tab of the Load a MIB File dialog box. If the selected MIB file is already present in the database, the MIB file is read, parsed, and loaded from the database. If the MIB file does not exist in the database, MIB Browser parses the MIB file, writes the output to the database and then loads the MIB file.

 

7.3.2.2 Parsing MIBs

 

MIB Browser enables you to parse the given MIB file and check for the macro constructs. It allows different levels of parsing and the parsing is done as per the standard definition of the macros. The parsing levels can be set in the MIB Browser Settings dialog box. The following tables describes the different levels of parsing that can be set and their corresponding checks.

Applications, while loading MIB files, perform the following operations.

While performing the parsing and validation of the MIB files, if the MIB modules fail to conform to the SMI standards the loading will not be not done. However, the application requirements might mandate the loading of the non-standard files. On the other hand, some applications might require a stricter check on the compliance to the standards.

The parsing and validating the syntax of the MIB file can be made configurable to suit the application requirements. MIB Browser handles this by providing parsing levels which facilitate to select the level of parsing required by the applications.

In addition to the above four parsing levels, MIB Browser supports another level, which is user-defined. In case of user-defined level, you can define your own parsing level with the required checks at runtime

    Note: It is recommended to use the higher parsing level (SERIOUS, CRITICAL) for validating the MIB file and not for loading the MIB file in the application. It affects the performance of the application while loading the MIB files, because it takes considerable amount of time and resources, such as memory, CPU usage, etc.

User Defined Parsing Levels

 

In addition to the four parsing levels, you also have another level, which is user-defined to define your own parsing levels at runtime. To add a user-defined parsing level, select the User-Defined option and click the Add button in the User-Defined Levels section. This displays the Customized Level dialog box.

By default, all the checks are included. Provide a name for the level in the Level Name text field. To add or remove checks from the level, select or deselect the checks and click OK. Note that if you select (deselect) a parent check, all its child checks are also selected (or deselected). Click OK to add this level to the user-defined level list.

The level of the parser has to be set in the MibParser before loading a MIB. This level, once set, is used for subsequent MIBs loaded. If the level needs to be modified for the next set of MIBs loaded, it has to be set again in the MIB Parser. In the Mib Settings tab of the MIB Browser Settings dialog box, select the required Parsing level, and click Apply.

The MIB file can contain one or more MIB modules. MIB Browser loads all the dependency files to resolve the MIB module. If the dependency file is not present, the IMPORTS failed error is thrown.

The parsing level can be set for the dependency file by selecting the Import File option and choosing Parsing Levels.

 

7.3.3 Graphs

 

One of the vital feature of the Net MIB Browser is the Graphs. The graphs depict the real-time plotting of the SNMP data. Currently two types of graphs are supported - line graph and bar graph. The SNMP data to be polled should be of integer or unsigned integer data type. Typically the values that are plotted will be of type Counter, Gauge or Timeticks.

Although the steps followed in invoking a graph and working on it is similar to the line graph and bar graph, let us understand it better under the following two sections:

Line Graph

The line graph depicts the real-time plotting of the SNMP data. Follow the steps below to invoke a line graph from the MIB Browser.

    1. Specify the proper agent hostname or IP address in the host field of the MIB Browser.

    2. Load the MIB in the MIB Browser. 

    3. Specify a valid variable. The variable must be an integer or unsigned integer (Counter, Gauge, Timeticks). This variable can be entered directly in the variable field or it can be chosen by browsing through the MIB in the Mib Tree.

    4. Click on the 'View real-time graph' button in the toolbar (or) choose View-->Line Graph menu item from the Menu Bar (or) use a shortcut Alt+L. By default, the Line graph option is selected in the MIB Browser settings panel, hence the line graph would be invoked when you do any of these operations. 

    5. This would invoke the updated Line graph showing the results of periodically polling the specified agent for the specified OID.

The various options available in the line graph is tabulated below:

    Options Description

    Polling Interval (sec's.)

    This specifies the polling interval time. The default value is 5 secs. You can change the interval time as desired.

    Average over Interval?

    Generally the actual values are plotted, selecting this option would take the average of the values.

    X-axis Scale (>300)

    This specifies the X-Axis scale. The default value is 300 secs and this is the minimum seconds. Changing this would alter the X-axis scale of the table. By default it is disabled, only on clicking 'Show polled values?' option the x-axis scale option is enabled.

    Show Absolute Time?

    By default the time is depicted in the graphs as only seconds. Selecting this option would give you the time in hours:Secs.

    Max Poll Duration (sec's)

    In order to see all the polled values in a particular time period, this option is used. This option by default it is disabled. Only on clicking 'Show polled values?' option this is enabled. the default value is 3600 secs.

    Show Polled Values?

    By default this option is disabled. When selected, all the polled values in a particular period of time is shown. Only on selecting this option the Max Poll Duration and Log FileName options are enabled.

    Log FileName

    The file name for the log file can be set here. By default the log file name is graph.txt. If the adjacent "Log Polled Values" is selected all the polled values are logged in this file. This option is not enabled when the MIB Browser is run as an applet, this is because of the security restrictions in case of applets.

    Log Polled Values?

    Selecting this option would log the polled values. This would enable the option Log FileName for the log file name to be set.

    Show Absolute Counters

    By default the graph plots only the difference between the two values. On selecting this the plotting of the absolute value is performed. 

    Restart

    The restart button is used to restart the polling

    Stop

    The stop button is used to stop the polling

    Close

    The close button is used to close the graph window.

Yet another way of invoking a graph is through the Table options. The MIB Browser can plot multiple graphs showing values for different variables from different hosts.

Bar Graph

The bar graph depicts the real-time plotting of the SNMP data. Follow the steps below to invoke a bar graph from the MIB Browser which is similar to invoking a line graph.

The various options available in the bar graph is tabulated below:

    Options Description

    Polling Interval (Sec.)

    This specifies the polling interval time. The default value is 5 secs. You can change the interval time as desired.

    Average over Interval?

    By default, the actual values are plotted, selecting this option would take the average of the values.

    Range

    Altering the range would change the X-axis scale of the table. The default
    value is 300 secs in the drop-down list box. The other options available in it are 600 secs and 1000 secs. 

    Show Absolute Time?

    By default the time is depicted in the graphs as only seconds. Selecting this option would give you the time in hours:Secs.

    Restart

    The restart button is used to restart the polling.

    Stop

    The Stop button is used to stop the polling

    Close

    The close button is used to close the bar graph window.

7.3.4 Debugging and Decoding

 

The MIB Browser application provides facility to view the debug output of the SNMP operations.

 

Invoking the Debugging window

    1. Click on the Debug icon  in the toolbar (or) choose View-->Debug from the menu bar (or) use a shortcut of Alt+D. This would invoke the debug window.

    2. As long as this window is opened, debugging is turned on, and debugging output is displayed in the debug window. When this window is closed the debugging is turned off. The image below depicts a Debug window.

    1. The three icons in the debug window provide the following function:

Invoking the Decoder Window

    1. To switch from the Debug window to the Decoder window, click on the Decoder icon. To switch from Decoder window to the Debug window click on the Debug icon.

    2. The three icons in the debug window provide the following function:

    Note: The Save and Print options are available only when the MIB Browser is invoked as an application and not in an applet. This is because of security restrictions in case of applets.

Performing the Decoding operation

 

The Snmp Decoder is used to decode the SNMP debug messages . The decoding can be done by two ways by using the

The figure below depicts the Snmp Decoder.

 

 

Copy-Paste option (This method is applicable for both MIB Browser application and applet).

 

This option can be used for frequent debugging.

The decoded message will be displayed in the bottom panel of the decoder window.

 

File option (This method is applicable only for MIB Browser application because the saving and loading of debug information files is done only in applications and not in applets). This option can be used if the debug message was stored in a file and decoding has to be done.

This will display the decoded message in the bottom panel of the decoder window.

 

Important: You can select the entire PDU debug message displayed in the debugger window with all the strings and paste it in the Hex PDU text area or load it in the decoder. The decoder will decode all the PDU dumps leaving the informative strings. The limitation in this is that the two continuous PDUs should have a string delimiter as a new line in between them. A sample PDU is depicted below

 

30 26 02 01 00 04 06 70 75 62 6c 69 63 a0 19 02 01 04 02 01

00 02 01 00 30 0e 30 0c 06 08 2b 06 01 02 01 01 05 00 05 00

Packet from: 192.168.1.215 : 161

DATA:

30 2e 02 01 00 04 06 70 75 62 6c 69 63 a2 21 02 01 04 02 01

00 02 01 00 30 16 30 14 06 08 2b 06 01 02 01 01 05 00 04 08

4b 41 4e 4e 41 4e 4b 41

 

The highlighted strings will be the delimiter between the two continuous PDU dumps. In case there is no string delimiter as above, only the first PDU will be decoded properly and the remaining PDUs will not be decoded.

Invoking the Decoder Window

7.4 Testing the Agent With SNMP Operations

 

7.4.1 SNMP GET

 

An SNMP GET Request can be sent to the Agent to get the values of the variable. Requests can be sent either from MIB Browser UI or from Command line. To perform the testing,

 

From MIB Browser UI

From Commandline

 

To send a GET Request from Command line, go to <Agent Toolkit Home>/examples/snmp/low_level_udpapps directory from the command prompt and use the following options.

where,

Similar steps have to be followed for testing a Table in the Agent.

 

7.4.2 SNMP GET-NEXT

 

An SNMP GET-NEXT request can be sent to the Agent to acquire the next OID of the selected variable. To perform the testing on a scalar variable,

 

From MIB Browser UI

From Commandline

 

To send a GET NEXT Request from Commandline, use the following options.

Please refer to SNMP GET for explanation of the Options used. Similar steps have to be followed for testing a Table in the Agent. Please specify the exact instance before sending a request to the Table. .0 instance is used only for Scalars.

 

7.4.3 SNMP SET

 

An SNMP SET request can be sent to the Agent to SET a new value to the selected variable. To perform the testing on a Scalar variable,

 

From MIB Browser UI

To perform the testing on a Table,

Please note that the instance value .1 has to be given in the Object ID field toward the end of the adiskName ID. Since the Index type of adiskTable is Integer32 , .1 has been given as the instance value. It can be any integer value.

 

From Commandline

 

To send a SET Request to the scalar variable agentDescr from Commandline, use the following options.

where,

To send a SET Request to the adiskName of adiskTable from Commandline, use the following options,

Here, .1.3.6.1.4.1.2162.4.2.1.1.2.1 refers to the OID of adiskName, .1 refers to the instance OID of the table, STRING refers to the Syntax type of the column, and 25 refers to the new value to be set for the column.

 

7.4.4 SNMP WALK

 

The SNMP walk operation does a continuous get-next operation. It takes the oid of the starting node, performs a get-next and if there is no error in response, repeats the get-next operation for all the nodes right from the starting node specified until it encounters any error in response i.e., an End-of-MIB view error or a change in the starting node OID.

 

This operation is supported through command line and is similar to GET-NEXT operations. To perform the testing on a Scalar variable, follow the steps given below :

 

From Commandline

 

To send a WALK Request to a scalar group from Command line, use the following options.

where,

To send a WALK Request to a Tabular group from Commandline, use the following options,

where,

7.4.5 SNMP GET-BULK

 

Get Bulk operation is performed on the Agent to get the values from a group of variables. This operation is supported only on v2c and v3 Agents.

 

To perform the testing on a Scalar variable,

 

From MIB Browser UI

Please note that Maximum Repetitions and Non-Repeaters values need to be specified for a GET BULK operation. Based on this count, the query is done on the group. You can find these text-fields in Edit -> Settings menu -> General Tab of MIB Browser UI. GET BULK operation will not be successful if the Max-Repetitions and Time Out value do not synchronize with each other. To know more about these terms refer to the FAQs - > General section.

 

To perform the testing on a Table,

From Command line

 

To send a GET BULK Request to a scalar group from Command line, use the following options.

where,

To send a GET BULK Request to a Tabular variable (adiskTable) from Commandline, use the following options,

7.4.6 MultiVarbind Requests

 

Multi-varbind operation sends many requests containing varbinds in the same PDU, i.e. the manager can query the agent with more than one request at a time. The functioning of the operation is such that when multiple requests are sent by the manager, the agent will not process each request one after another, but groups all the varbinds under a parent OID as a single request before calling the instrumentation layer. This minimizes the number of requests processed by the agent and also increases the performance of the agent as the response time is minimal.

 

For example, add the nodes of scalar group and nodes of tabular group in AGENT-SAMPLE-MIB to the multi-varbind text field as shown below:

 

.iso.org.dod.internet.private.enterprises.adventnet.demo.agentSystem.agentDescr.0:

.iso.org.dod.internet.private.enterprises.adventnet.demo.agentSystem.agentLocation.0:

.iso.org.dod.internet.private.enterprises.adventnet.demo.agentSystem.agentAvailMemory.0:

.iso.org.dod.internet.private.enterprises.adventnet.demo.agentDisk.adiskTable.adiskEntry.adiskName.1:

.iso.org.dod.internet.private.enterprises.adventnet.demo.agentDisk.adiskTable.adiskEntry.adiskUsed.1:

 

Here the agent processes two requests for five varbinds send from the manager by grouping the scalar nodes of agentSystem as a request and tabular nodes of agentDisk as another.

 

To enable Multivarbind operation in MIB Browser UI, 

If there is a read-only variable, the SET operation will not be successful. Similarly GET-BULK will not be successful if the Max-Repetitions and Time Out value do not synchronize with each other.

 

7.4.6.1 Atomicity or MultiVarbind SET Requests

 

While processing a Multivarbind SET request, if the SET fails for any subsequent varbind, the previous successful SETs in the multivarbindare rolled back to the original values. This concept is known as Atomicity (Roll Back). This feature is handled within the "processSetRequest" of the XXXRequestHandler class and the Agent API.

 

Enabling Rollback Method

 

By default, Roll Back method is enabled in an Agent. When a Multivarbind SET request arrives from the Manager the processes carried out in an Agent are,

Disabling Rollback Method

 

This Rollback functionality method can also be disabled using the following piece of code in the "initSnmpExtensionNodes" method of the Generated Main File of the Agent,

7.5 Using Row Status

 

SNMP Operations also include Adding a Row and Deleting a Row from a Table using Row Status Textual Convention (v2c). To define Row Status, please refer to Defining a MIB section.

 

Different Levels in Row Status

 

The different levels supported by Row Status are: -

Adding a Row

 

To add a new row to a Table from the Manager that particular Table should be an SNMPv2 Table having RowStatus column i.e., the MIB should be a V2 MIB supporting Row Status . A new row can be added to the Table using any of these three ways.

CreateAndWait

 

In this method, the RowStatus column should be first SET with the value 5 (CreateAndWait). Then, the other column values should be added. Finally, the RowStatus column should be made "Active".

  1. For example, in the aaplicationTable of Agent-Sample-MIB, the aaplicationTablestatus is the Row Status Column. To add a row (with index value 3) in this table,

  2. Select aaplicationTablestatus and in the Object ID field add the table instance ".3" to the OID as follows .iso.org.dod.internet.private.enterprises.adventnet.demo.aapplications.aaplicationTable.aaplicationEntry.aaplicationTablestatus.3

  3. and set the value with "5" (CreateandWait) in the Set value field.

  4. Similarly, select aaplicationName and set the value for .3 instance as "MIB Editor".

  5. Select aaplicationVersion and set the value for .3 instance as "5.0" in the Set value field.

  6. Select aaplicationInstallDate and set the value for .3 instance as "2002" in the Set value field.

  7. Select aaplicationTablestatus and set the value for .3 instance as "1" (Active) in the Set value field.

  8. Thus, a new row is created in the aaplication table with the aaplicationID (index) value as 3.

CreateAndGo Using MultivarbindSet

 

Instead of sending multiple SET requests to the Agent, a new row can be created in a Table in a single SET method. For this, add some relevant values to the columns of a Table with the RowStatus column as "4" (CreateAndGo) using MultivarbindSET option. Check Multivarbind option available in Edit -> Settings menu of MIB Browser UI.

 

To explain it with an Example, take the aaplicationTable of Agent-Sample-MIB. The aaplicationTablestatus is the Row Status Column. To add a row (with index value 4) in this table,

  1. Select aaplicationTablestatus. In the Object ID field add the instance for the Table OID as ".4". Then, set the value for .4 instance as "4" in the Set Value field.

  2. In the right side bottom most part frame of MIB Browser UI, you can find the Multivar check box (after enabling it in MIB Browser settings). Check the MultiVar option and Add to list. This will add the RowStatus column with its value in the list.

  3. Similarly, add the following columns to the list.

  4. Select aaplicationName and in the Object ID field add the table instance ".4" to the OID. Then set the value for .4 instance as "MIB Browser". Later add it to the Multivarbind list.

  5. Select aaplicationVersion and in the Object ID field add the table instance ".4" to the OID. Then set the value for .4 instance as "1.0". Later add it to the Multivarbind list.

  6. Select aaplicationInstallDate and in the Object ID field add the table instance ".4" to the OID. Then set the value for .4 instance as "2002". Later add it to the Multivarbind list.

  7. Now, do a single SET operation by which all the values are added to the Table. Thus a new row is created in the aaplication table with the aaplicationID (index) value as 4.

CreateAndGo using SNMP Table

 

A new row for a table can also be created using SNMP table User Interface (UI). On enabling the SNMP Table icon after selecting the appropriate table from the left side MIB tree a dialog box opens.

Deleting a Row

 

By changing the Row Status value to 6 (Destroy) a row can be deleted from the MIB Browser UI itself. You can also delete an entry using the SNMP Table. By selecting the entry to be removed, changing the row status value to 6 and refreshing the table, the entry gets removed.


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