How to Add a User Defined Collector in Entuity Network Analytics (ENA)?

How to add a User Defined Polling Collector in Entuity Network Analytics (ENA)

An Introduction

This article is going to show you the basic concepts of the User Defined Polling functionality and how to add a User Defined Collector in Entuity Network Analytics to have better control of your network management as you navigate around your network.

What you’ll Learn

  • User Defined Polling
  • User Defined Polling Collector
  • Entuity Network Analytics
  • Network Management


7 min

User Defined Polling Capability

Entuity uses a set of attributes to hold normalized data samples that can be obtained from a wide range of devices of different models from different vendors, while some of the SNMP MIBs from which this data obtained are industry standard and supported by all vendors. There are many items that can usually only be gathered from vendor proprietary MIBs which naturally differ between vendors. Some examples of components for which polling of proprietary MIBs is often required are the device model, serial number, processors, memory and fans.

Learn more about ENA User Defined Polling from our blog.

Adding User Defined Collectors

Under these circumstances, the Entuity device certification team are usually able given a mib-dump of the device in question to prepare and supply additional configuration files to achieve the desired functionality. However, even though the turnaround for such requests are often as rapid as a day or two, the user-defined poling capability can be used to achieve the same result if the data is available in the device MIBs. The way to access it is understood. Under these circumstances, you’ll need to define a new collector for an object attribute and there’s a tutorial video available to cover the procedure.

Adding User Defined Attributes

If there’s a need to add one or more additional attributes to an existing object such as a compression ratio for a one data compression device, this would require new attributes with their corresponding collectors to be defined. There’s a UI wizard provided for this purpose and the dedicated tutorial video to cover the procedure.

The specification of the attributes on objects and streams defines the meaning of the data whereas the actual polling of the SNMP data to populate each attribute is performed under the control of a collector. In order that different SNMP requests can be issued to different makes and models of devices. To obtain the same type of information, Entuity allows multiple collectors to be associated with each attribute. On the initial attempt to populate an attribute that has multiple collectors. Here are some basic rules:

  • The collector with the highest priority setting is considered first.
  • If filter setting is checked in the context of the object on which the attribute is located and returns a boolean true, the collector method is executed to obtain the attribute contents.
  • If either the filter returns false or the method returns a null, this collector is skipped and the collector with the next lower priority setting is examined. This sequence continues until either a collector successfully returns a value or the list of available collectors is exhausted.
  • The successful collector is recorded. When the attribute needs to be polled afterward, the same collector can be reused without having to reattempt the whole sequence again.

The sequence will be reassessed from time to time under the control of the StormWords discovery mechanism, so changes to the devices that affect the way in which they should be polled will be accommodated.

On occasions, you may encounter an example of a managed device where some of its attributes such as the model or serial number or sub-components such as fans, power supplies, processors or memory pools are not being populated despite they’re being suitable data available from the MIDs supported by that device.

The Entuity device certification team can usually provide an additional configuration file to address such an issue provided they’ve sent an SMP dump of the device and have access to the vendors’ mid definition files. However, the user defined polling system allows such changes to be made without the assistance of Entuity engineers. I’m going to show you an example of how this can be done.

I have a wireless access point under management that was manufactured by Aerohive. There’s no CPU or Memory Utilization statistics being displayed and the Serial Number is blank. I know that all three of these items were available from one of the vendor MIBs so this is an example of where an additional collector can address the shortfall. I’m going to focus on the serial number for this tutorial.

User Defined Polling Collectors

I’ve selected the user-defined polling page from the administration menu and chosen the Collectors tab.

Category and Object Type

The attribute that I am going to update is the serial number, which is an object attribute. I have selected that option from the category menu. There are no existing user defined collectors for object attributes on this system. It’s a good idea to specify what type of object the new attribute is to be defined for at this point. I will select the autonomous wireless access point.

Adding a New Collector

1. Search for an example device

Now it’s time to bring up a dialogue to add a new collector. An existing device that needs new collector needs to be selected, you can either simply click the search button to display all your managed devices or enter a substring from its name to limit the search before clicking the button. This is the device will be used in this example.

2. Rename with “ud_”

You will able to see that the object type has already been correctly defined, so the next step is to select the appropriate attribute which is the serial number. Also, it is a good point to enter a suitable name for this collector which needs to be unique, and it’s wise to make it obvious what its intended to achieve. The name should begin with “ud_” and in this case I will add “aerohive_serial_number”. It is necessary to enter a description to help others who may need to make changes at a later date. Then click the Browse button to find the SNMP ID.

3. Import MID

The vendor proprietary or Enterprise MIPS are located under the Private MID branch. You can see from the image that it is currently empty and I am going to load a MID from the vendor which is Aerohive in this case.

To make the MID available to be loaded, firstly import it into the list by using the managed MIPS function. I already have a copy of the MID and this allows it to be uploaded from my desktop to the Entuity server. This is the MID file that I’m looking for. It can then be selected and parsed by clicking the load button.

In this case, the pausing failed for complaining the absence of another MIT file. So I am going to import that one as well. Only the primary MID should be selected before clicking the load button. This time the load was successful and I can close this dialogue to continue.

Under the enterprise branch, you can now see the new Aerohive MID and select it. I’ll use the find feature to search this MID for the first entry containing serial in its name. The description confirms that as the file I want.

This is a scalar which means there’s only one entry, while a table of values would be indicated with an icon like this.20-15table icon 

Then use the Get function to read its value from the selected device. This looks like a possible serial number.


  • As this is a scalar, I will leave the index set to “None”.
  • If some manipulation of the result needed to be performed to format it properly, that could be achieved by modifying the method statement.
  • The filter statement has been automatically configured to limit the scope of this collector to only apply to this vendor’s devices. If that’s not what you want, then it can be modified.
  • The priority setting is only relevant when multiple user-defined collectors are applied to the same attributes as the one with the highest priority setting will be evaluated first. In my case, I only have one collector to this attribute on this type of device, so I don’t need to adjust it.
  • The last item is the transform setting, which allows different enumeration schemes to be normalized but as this is not an enumerated OID, it can be ignored.

Clicking okay and adding the newly defined collector to the list. It will take effect as soon as that attribute is next polled.

Here’s the end result and you can see that the serial number is now being properly populated with the newly obtained value.

ENA Tips:

The idea of combining multiple sub-reports into a higher-level report can be taken to yet another level if you build sub-reports by combining other sub-reports together. The main point to remember would be that when placing sub-reports side-by-side, their combined widths which are defined. So when you build a sub-report, pay attention to not exceed the width allocated in the final report. Another point you should remember when you build a report and you’re considered to be its owner, which allows you to modify its configuration at a later date via this icon.

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