Retrieving Table Data

The data in the table can be retrieved with ease. The following steps gives you an insight into how to open the Data Table panel and work on it using the various options.

1. Specify the proper agent host name or IP address in the Host field of MibBrowser.

2. Load the MIB file in MibBrowser. To know more on Loading the MIB file, refer the Loading and Unloading MIBs section.

3. Specify a valid OID or select the OID by traversing through the Mib Tree. The OID should be a valid table OID.

4. Click the View SNMP data table button on the toolbar or choose View-->Snmp Table from the menu. You can also use the shortcut key combination Alt+T.

5. This would invoke the SNMP Table of the specified table OID. The figure below depicts the SNMP Table panel.

Click the Start button at the bottom of the SNMP Table panel. The retrieval of data begins and the columnar objects are obtained and displayed in the table.

7. Click the StartPolling button to start the polling of the table. The polling interval is based on the Polling Interval value set using the Settings option.

8. Click the StopPolling button to stop the polling.

9. When you don't use the polling option, click the Refresh button to refresh the table.

10. The SNMP Table panel might retrieve more data so that the frame depicting the columnar objects would run to pages. When you need to navigate through the pages (rows), use the Next and Prev button.

11. The Page option at the bottom of the panel is used to specify how the table retrieval needs to be done. If the option is origin, the table is retrieved from the origin. If the option is index, the user can set an index value from which the table can be retrieved.

12. The host name as specified in MibBrowser will be displayed in the Host field. The page number and the number of rows in that page are displayed next to it.

13. It is possible to configure the SNMP Table panel. Click the 'Settings' button. This displays a dialog box with various options to configure the Table panel. The image below depicts the SNMP Table Settings panel.

The various options available are listed below.

• PollingInterval - This specifies the time interval between each retrieval of data. The default value is 5 secs.

• Page Size (Rows) - The number of rows to be retrieved is set here. The default value is 50.

• No Of Column View - This specifies the number of columns to be displayed in the SNMP Table panel. The default is 5.

• Split Columns - When the size of the PDU exceeds the limit, the agent sends the error message "Too Big PDU Error". This field serves as an option for splitting the PDU. By default, the PDU is split into half. If the number of varbinds is set by the user, then multiple request with PDU containing number of varbinds set is sent.

• No of Columns/Request - This field is enabled on selecting the Split Columns check box. You can specify the number for splitting of columns.

• Port - This field specifies the port to which the request is made.

• Table - The table OID is specified here.

• Max-Repetitions - This value specifies the number of lexicographic successors to be returned for the remaining variables in the variable-bindings list. The default value is 5. This is enabled only when the Retrieval Mode option is set to GetBulk.

• SnmpVersion - This gives the option to switch to any of the three versions of SNMP-v1, v2c, and v3.

• Graph Type - This gives the option to switch between Line Graph and Bar Graph.

• Retrieval Mode - By default, GETNEXT is enabled. The GETBULK option is enabled only on selecting v2c or v3.

14. If you need to view the graph, click the Graph button. The section on Graphs gives you more details on the MibBrowser Graph component.

15. You can also add and delete rows in the table and a detailed explanation has been given in the next two sections.

16. In a table, if one of the index columns is an external index, i.e., the index value is shared by some other table, then the table is called an Augmented table. Augmented table comes into picture when there is a one-to-one dependency between rows of two tables. This situation might arise when a particular MIB imports another MIB and shares a single table. For example, ifXTable defined in IF-MIB is an augmented table, which has an external index ifIndex augmented from ifTable. Clicking the 'Augmented Table' button shows the columns of the table which augments the index from the original table.

17. Click the Index Editor button to edit the index and view the rows from corresponding index.

18. To make changes to a particular column values, right-click the columns. The various options available are:

• view column node details - This option gives the MibNode Information of the selected column.

• edit the header name for selected column - This invokes a dialog box in which you can change the header for the selected column. The image below is a screen shot of the dialog box.

• view graph for selected cell(s) - This option invokes the graph. It is possible to view the graphical representation for more than one cell by multiple selection of desired cells.

• add a new row to the table - This option is the same as the Add option available in the Table panel. A detailed overview on adding a row is given in the Adding a row section.

• delete the selected rows from - This option is the same as the Delete option available in the Table panel. A detailed overview on deleting a row is given in the Deleting a row section.

• view the not-accessible index - A request cannot be sent to an index that is not accessible. In the table, the not-accessible index is not visible. Selecting this option would enable you to view the not-accessible index values.