Discovery and Inventory Group

SNMP Data Mapping Tables

The heart of Agentless Inventory (sometimes known as Inventory for Network Devices) is custom values available via SNMP. By setting up new tables and columns, these values can be collected and stored, available in reporting and filtering on Network Devices. Setting up these tables and columns is important, and there are several gotchas to be aware of to ensure success. The following process walks through setting up a customer table to be captured by SNMP devices.

1. In the Symantec Management Console, browse under Settings > All Settings > and in the left-hand pane browse under Discovery and Inventory > SNMP Settings > and select SNMP Data Mapping Tables.
2. Click the New icon to create a new table.
3. Provide a Name. This name will become the table name is the following format:
   Name provided: SNMP Cisco 8540 Switch
   Resulting SQL table name: Inv_SNMP_Cisco_8540_Switch
4. Click OK to move to the configuration step.
5. Click New under Table columns.
6. Provide the values as applicable, following the guidelines below:
   • Name: This will become the column name. Note that while spaces are supported, it will require the underlining reporting or filtering SQL to bracket the column name.
   • Type: This will be the data type for the column in SQL. An appropriate value for what is being captured should be selected. The common selecting (and default) is “string”.
   • Length: This should be long enough to contain any expected values. Adding extra typically does not hurt anything.
   • Key: Only select this option if the value captured will be specifically unique for each device reporting it. If it is not, two devices with the same value cannot reside in the table at the same time. Data can be overwritten and/or rejected. If in doubt, do not select this option.
   • Object ID: This will open up the MIB browser, allowing a user to select the value they wish to capture. The select must be accurate as this is the OID the engine will used when fetching data for this column from SNMP devices.
     
7. When selecting the MIB value for a column, use the following guidelines:
   • Double-click on the folders in the UI to expand them.
   • Select a value to populate the properties fields below.
   • Review the properties field to ensure you have selected the value you require.
     
8. Click OK to save the column.
9. Repeat the process of creating columns until you have the columns you desire. Note that the ID column and Resource GUID of the device will be created but not shown in this section of the user interface.
10. NOTE! When going through this process, the ASPX session may timeout, so be ready to save changes as you go. Alternatively you can refresh the console and start again once you’ve identified what values and MIB selects to use.
11. Click Save changes to save the current progress.
12. Click on the Device mappings tab. (NOTE! This step is often forgotten, ensure that it is followed or no device will collect inventory for the new table)
13. These are the same Device mappings used when working in Network Discovery. Any device you wish to run the new SNMP calls against, and thus capture the custom data, must be checked in this list.
14. If you sort by Manufacturer it can make it easier to select the devices you need.
15. Once you’ve checked all applicable devices, click Save changes again.
16. NOTE the message that appears:
    
    Saving this table will delete all information and recreate the table, are you sure you want to do this?
17. This will happen any time the table mapping is saved, whether merely adding a device mapping or adjusting, modifying the columns. This means all previously captured data WILL BE ERASED. In this way it is highly recommended to have all device mappings and intended columns configured. If you do need to adjust it, run an Agentless Inventory again to repopulate the table.
18. The process is now done!

NOTE: The Test on Device button has defects which render its effectiveness null. Please use a 3rd Party tool that queries SNMP for alternative ways to test.

Repeat the above steps for any data class (table) you wish to create. Be sure to follow all the steps so that mistakes don’t cause failure to gather the data, or the need to adjust the configuration and thus delete and recreate the table.

Next Article:

Network Discovery and Inventory for Network Devices Tips and Tricks Article 10