ILMT & BigFix:

How to Install, Configure and Maintain for Sub-Capacity Licensing

ILMT & BigFix: How to Install, Configure and Maintain for Sub-capacity Licensing

  • 25 March 2021
  • Randy Bal
  • 4.33 minutes to read

In today's world, applications can be hosted on different platforms. It’s not uncommon that applications shift between virtual, containerized and cloud platforms. From a licensing perspective, a change of platform will most likely result into a change in the available capacity on which the software is installed and/or running and as such have an impact on the required number of licenses. A situation software asset managers and/or software license manager would typically need to watch out for.

This article provides an overview of the installation and configuration of BigFix and IBM License Metric Tool (ILMT).

Who is Required to Make use of ILMT?

Almost any organization that is making use of IBM software programs is required to use ILMT, if and when an end user would like to make use of the possibility to license only the sub-capacity of a server. The only situations which would not require you to use ILMT are if:

  • You decided to license the full capacity of your server(s) (instead of the sub-capacity)
  • You have a contractual agreement with IBM which allows you to use another SAM tool (e.g. Flexera) for your sub-capacity licensing
  • You have less than 1.000 PVU licenses measured in full capacity and less than 1.000 Employees

ILMT does not yet provide support for the Eligible Virtualization Environment or Eligible Sub-Capacity Product

How to Install ILMT?

You may be surprised that, before installing ILMT, you first need to install BigFix. Both the BigFix platform and ILMT are free for IBM’s customers. BigFix is a scalable and versatile product with many different applications (capabilities).

In order to be eligible for sub-capacity licensing, at a minimum you need the BigFix Platform and the ILMT application to be installed. A single server with BigFix and ILMT (4 CPUs 16GB memory) can manage up to 1000 endpoints (agents) and can easily be scaled up or down managing up to 100.000 endpoints.

The IBM Knowledge Center provides guides for planning, installation, configuration and use of BigFix and ILMT.

  • BigFix Knowledge Center
  • IBM License Metric Tool Knowledge Center


In our experience, the biggest concerns with regards to the installation of ILMT and BigFix are usually raised by the security teams. Most of the BigFix/ILMT installations and implementations have technical requirements, but for some, workarounds can be implemented. For instance, a workaround can be implemented to overcome the #1 concern for the need to allow UDP traffic through your routers or firewalls.

To make sure you don’t face issues when it comes to the BigFix/ILMT installation, prepare beforehand by validating the following steps:

  • Network connectivity (TCP/UDP) between agents, virtual infrastructure and BigFix is in place
  • You have internet access. BigFix requires access to the internet.
  • You have permissions on the virtual infrastructure
  • You addressed concerns regarding system management functions of BigFix
  • You have permissions to install agents on systems containing IBM Software
  • You know where IBM software has been deployed
  • You address concerns regarding possible impact the software scans might have
  • You schedule regular management of BigFix and ILMT

How to Install BigFix?

When all requirements are met (an operating system and database are prepared), installing and configuring BigFix and ILMT will usually take 8 hours. This includes installing BigFix server, retrieving License Metric Tool content and deploying BigFix agents. The installation of BigFix might not be too complex, however without experience, BigFix can be confusing.

In BigFix, fixlets, tasks, relevancy, sites, domains are common terms. It is recommended to review the Console Operators Guide section in the BigFix Knowledge center link.

BigFix Fixlets

After BigFix is installed, continue the configuration of BigFix and ILMT using the BigFix console. BigFix retrieves fixlets via the internet from the BigFix-content-servers. Fixlets are scripts which can be executed on single or groups of devices. An example of such a fixlet is a Microsoft Security Patch. A fixlet is only visible for devices for which it is relevant for; in other words: that Microsoft Security patch is only visible (relevant) for Microsoft systems, but is invisible for Linux devices.

The ILMT installer is also provided by IBM in a fixlet. To install or upgrade ILMT, simply search for the fixlet “Download IBM License Metric Tool” and execute (take action) it to start the installation. Once the fixlet is completed, perform the initial configuration as explained in the ILMT knowledge center. Next step is to deploy the fixlets to install the hardware and software scanners, IBM software catalogs and the VM Managers.

New versions of BigFix and ILMT are provided and can be upgraded through a fixlet.


The installation, configuration and proper management of IBM’s License Metric Tool (ILMT) and its associated BigFix platform are not as simple as you may think. End users typically underestimate all the different steps and actions that are required to be followed, in order to be eligible for sub-capacity licensing. It’s very often that end users struggle with the installation, configuration and proper management of their ILMT/BigFix platform. This, since the in-depth knowledge and expertise and required time to do this in a complete and accurate manner is quite often not available within an end user organization itself.

We developed specific ILMT services for those who acknowledge the complexity around the installation, configuration and continuous management of their ILMT environment and that do not have the expertise in house themselves. Would you like to understand more about our ILMT Health Check Service or ILMT Managed Service and how this would fit your business needs? Don’t hesitate to reach out to us.

Get to Know Our ILMT Services

Would you like to understand more about our ILMT Health Check Service or ILMT Managed Service and how this would fit your business needs? Don’t hesitate to reach out to us.

Meet the IBM Advisory Team

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Randy Bal, Solution Consultant IBM Software

Randy Bal

Solution Consultant for IBM Software

Specialist for IBM Software Licensing and IBM License Metric Tool

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