NX License File Basics
NX License File Basics
This article highlights the essential components of an NX license file and a quick overview of what needs to be done once a license file is received from Siemens.
Overview
Enabling an NX license is a very comprehensive precursor to accessing and using the NX software. Without a license file or borrowing a license from a server that has an active license, NX cannot run. The basis of understanding why and how the license file is necessary to run NX includes the prevention of piracy and also the management of the user base within a customer site or network. Although the management of license service processes can be somewhat extensive, it’s really a simple concept, fundamentally.
Siemens licensing is actually an outsourced application that is developed by Flexera Software, LLC. It is used in many of the Siemens PLM products and includes configuration and control programming contained in a single “tools” type dialog. More on this later.
I will add a bit of a disclaimer here in that there are parts of the licensing and proprietary code that I’m not sure I fully understand. But for the average user/administrator, that’s not really necessary as long as the installation and configuration is successfully completed.
How It Starts
A customer can download the NX software either from Siemens website or from our portal (please note you must be a current Swoosh customer to access).
However, downloading the compressed installation file and unzipping the file is insufficient to run the software. It’s the license file that enables the software to run.
When a customer purchases NX, in addition to the administrative channels and financial work flow processes, Siemens will email a 7-day temporary license file to the customer that will show two things:
- The customer’s Webkey account number, an access code needed to access proprietary information on the Siemens website, such as GTAC help, the data upload/download site, etc.
- The customer’s Sold-To, or Install ID, a 7-digit number assigned by Siemens to the customer’s purchase order for that NX software bundle. A single customer can have more than one Sold to number. Often, there will be different Sold-To’s for the different locations/facilities. And there will be different Sold-To’s if the customer switches providers, such as going from one partner to another.
The 7-day temp license file is very similar in content to the permanent or annualized license file, which I’ll show in detail shortly, but it contains less information. This 7-day temp license file is generic and allows the software to run on any qualified device or computer and this is often used by salespeople to allow a customer to try out the software before purchasing. There are also temporary licenses for longer trial periods such as 30-days and longer. These temporary licenses contain an advisement that explains the limited enabling and that specific computer information needs to be registered with Siemens…

Once this initial email with the temporary license file has been sent, then Siemens must be given additional information about the environment and device(s) that the software is to be used on, in accordance with the specific type of licensing purchased. There are several different types of licenses that provide a wide diversity of options that can suit customer requirements and affordability:
- Fixed node – license file contains dedicated data content that only allows the software to run on one specific computer or device and is based on that computer’s identifier information (clarified later)
- Floating – a server type license that can be installed on any computer or device and is accessed by other devices on which NX is intended to run.
- Combinations of both of the above options that will enable the software to run on specific devices, enable only certain applications or modules of the software to run on certain devices or for certain user groups, or other managed user/device/application-based scenarios. These kinds of licenses can even be coded to allow users from different departments, locations, facilities, even countries and continents to run the software via the internet.
- Dongle enabled – the license authorization code actually resides on a plug-n-play device, somewhat like a thumb or external drive, enabling NX to be run on any machine on which the software is installed but only while the dongle is connected to the device.
In whichever above scenario is purchased, the Siemens license administrator will need to be provided five things:
- The customer’s “Sold to ID”, available in the original, temporary license file.
- Adequate proof that the customer’s maintenance contract is active. (Trust me, they’ll know.)
- The host name of the computer on which NX will be used or that will used as a server to other computers that have NX installed on them. This host name can be accessed by pressing MB3 (right-click) on “This PC” or “My Computer” (based on operating system) and choosing “Properties”:

- The MAC address, sometimes called Physical address of that computer, a string of 12 characters. Often you will see these strings separated into pairs of characters by dashes, e.g. A4-34-87-C2-BE-9G
- The Composite ID (CID), a 12-character string that is assigned by a computer’s operating system to devices installed in a computer, generally for the purposes of communications, such as the Ethernet card, wifi card, etc.
The MAC address and the CID can be accessed along with the next bit of information using the NX “Licensing Tool” which is installed when NX is installed. This icon is easily accessed in Windows 10 by pressing the Windows key on the keyboard.

When selected, the MAC address and CID are listed in the Composite ID group…

It is usually best to use the CID of the Ethernet card because sometimes, wifi is not enabled or, if wifi is not available at the location, it may not be active. The Ethernet card is almost always enabled and tends to work the best.
Fixed node license files
To keep it simple, let’s review a fixed node license file that is intended to limit available applications (modules within the software) to specific computers (that meet the hardware certification specifications (available on the GTAC website).
Once the above information is sent to Siemens, they will send an email to the customer containing the NX license file and, depending on the products purchased, other licenses for Teamcenter, etc. The file will be initially named “License_Ugslmd.txt” when emailed.
Due to firewalls and other anti-malware and protective software security programs, the file extension is defined as “,txt” in order to pass through those email filters successfully. The customer should rename the file with the more common format that indicates it is a Siemens license file, such as “splm12.lic”, where “12” indicates the version of the license file and the “.lic” is necessary for the NX software to recognize and read it. A sample of the content of the fixed node license file follows. Note the version of the license file inside the header at the top surrounded with # symbols.

- The first section of the file lists the “packages” as product numbers (bundles) and specific application modules that are licensed by the file.
- The “options” listing is a collection of proprietary coded strings of hexadecimal characters in groups of 4. This is an example of the customized data that is generated from the MAC address and CID of a particular computer.
- This is then followed by individual “feature” sections that will include specific NX license server version (Parasolid), expiration date (or “permanent” if so licensed), fixed node host id references (MAC address), options information, and finally, more hexadecimal code that enables that specific functionality for that specific
Floating “Server” license files
A floating license file is similar to the fixed node license explained above with some minor differences in content but major differences in capability and how it is applied.
When a customer needs to provide more than one computer (user) with NX licensing simultaneously, then a floating license server can be employed, allowing an unlimited number of users to run NX using that one license file that resides on the server. However, the number of simultaneous users is limited to the total number of licenses authorized by the license file. In other words, the license server stores the total number of licenses in a pool that can be accessed by individual users at any time until the available licenses have all been “taken out”. Any subsequent users who request a license from the server by starting an NX application for which all licenses are currently being used will receive a popup alert indicating that the particular module they wish to use is not available.
One of the main differences is that directly underneath the header of the file will be a “server line”. This will actually start with the word “SERVER”, followed by the computer host name where the license file will reside, the CID of that computer, and the port # that is to be used.
- Sometimes, Siemens will send floating license files with server lines containing “YourHostname” instead of the actual customer’s computer host name. This will need to be edited by the customer – the actual host name must replace “YourHostname”.
- This must then be followed by the host computer’s CID. In temporary license files, that will often just say “ANY”, meaning any computer can be used. For all other license file types, the CID will need to be entered. This and the host name are the only edits that are required, generally.
- Lastly, the port number will be listed and by default, the port number “28000” is used. This can be any port number that is available on the computer but is best left as is. Sometimes 27000 is used in environments with multiple licenses or more complicated configurations.
- The next line below the server line will be the “vendor” line. This identifies which specific software product is being licensed and reflects the actual server process that needs to be running on the computer for this license file to enable the software to run. When changes are made to the configuration, this service usually needs to be stopped, restarted, and the license file be reread.
- After that, the same “package” section follows that lists the license bundles which is then followed by sections similar to the above “features” definitions but are identified as “increments”.

At the bottom of either the fixed node or floating license files will be a “Software License to Feature Name Cross Reference” listing. This summarizes the actual functionality in groups, listing the specific “license features” under the bundles that are enabled by the license file.

Summary
The Flexera “Flexnet” software that enables NX and other Siemens PLM Software products to run can be as complicated as necessary to prevent unauthorized use but, when properly installed and configured, is virtually transparent to the user of the application. As a CAD or CAM user, all of this information is nonessential unless there are problems with the licensing or network. Then it is helpful to understand how it is supposed to work or at the very least, what is failing when NX fails to start successfully.
I hope this article provides you with some insight into what else is actually processing when you are creating your models, assemblies, drawings, toolpaths, and analyses and perhaps it even takes a little of the mystery out of understanding an installation of NX licensing.
