Restricting access to an Ansys license on a license server



Access to the license can be controlled by the ANSYS License Manager on your license server. There can also be a timeout set for license asage. These access rules can be defined in the 'ansyslmd.opt' options file.

Important note

This article only applies to those using Ansys FlexLM licenses. Those using legacy Sentinel LDK licenses (starting with license number L or T such as L100000) should see this article. Those with black USB network licenses (from 22000-40999) should see this article
Authored By Don Dickinson (credit to Lumerical for most examples)


  • Ansys License Manager.
  • Access to the license server directly or via remote access. 
  • Root or administrator privilege. 

Examples of access control

  • Reserve a set of licenses for a particular group of users or a single user.
    e.g. if one user always needs access to MODE, a license can be permanently reserved for this user.
  • Reserve a set of licenses for a cluster.
    e.g. 10 FDTD engine licenses can be permanently reserved for use on a local on-premise cluster.

See this article for the full list of license features by product. 

Location of the 'ansyslmd.opt' file

Note: Create the 'ansyslmd.opt' (text) file, if this is not found in your installation folder (default location shown below). Sample 'ansyslmd.opt' file can be downloaded here


"C:\Program Files\ANSYS Inc\Shared files\Licensing\license_files\"



Keywords to use


  • Defining a user that for use with an option. This option is case-sensitive.
     USER username
  • Example: Reserve FDTD full license (GUI+Solve) to USER bill.
    RESERVE 1 lum_fdtd_gui USER bill
    RESERVE 1 lum_fdtd_solve USER bill


  • Define a group of users for use with any options. This option is case-sensitive.
    GROUP group_name user_list
  • Example: Define the GROUP 'Researchers' consisting of users tom, jim, and bill and Reserve 1 'lum_fdtd_gui' license to the GROUP. 
    GROUP Researchers tom jim bill 
    RESERVE 1 lum_fdtd_gui GROUP Researchers
    RESERVE 1 lum_fdtd_solve GROUP Researchers

NoteEnsure that a USER only belongs to one (1) user GROUP.


  • Define a group of hosts (computers) for use with any options. This option is case-sensitive.
    HOST_GROUP group_name host_list
  • Example: Define the HOST_GROUP HPCcluster consisting of nodeOne, nodeTwo, and nodeThree.
    HOST_GROUP HPCcluster nodeOne nodeTwo nodeThree

Note: Ensure that each HostName only belongs to one 1 HOST_GROUP.


  • Allow a user or predefined group of users/hosts to use the license for this feature. Anyone not in an INCLUDE statement is not allowed to use that feature. EXCLUDE supersedes INCLUDE; conflicts between the EXCLUDE list and the INCLUDE list are resolved by the EXCLUDE taking precedence.
    INCLUDE feature type {name | group_name}
  • Example: Allow the GROUP 'researchers' to use 'lum_fdtd_gui' license.
    INCLUDE lum_fdtd_gui GROUP researchers

Notes: INCLUDE is required for USER_BASED or HOST_BASED features. The system administrator specifies which users are allowed to use the product, via INCLUDE, and the license limits the number of users that are included.


  • Allow a user or predefined group of users/hosts to use all license features served by the vendor daemon on the license manager. Anyone not in an INCLUDEALL statement is not allowed to use these features.
    INCLUDEALL type {name | group_name}
  • Example: Allow USER 'jane' to use all licenses for the vendor daemon on the license manager.


  • Limits usage for a group or user.
    MAX 2 feature type {name | group_name}
  • Example: Limit the group 'lum_users' to 2 licenses for 'lum_fdtd_gui' feature.
    MAX 2 lum_fdtd_gui GROUP lum_users


  • Deny a user or predefined group of users/hosts access to a license.
    EXCLUDE feature type {name | group_name}
  • Example: EXCLUDE the group HPCclusters to use 'lum_fdtd_gui' feature.
    EXCLUDE lum_fdtd_gui GROUP HPCclusters


  • Deny a user or predefined group of users/hosts access to All licenses on the current FlexLM. If the type is not defined it will exclude all license features for all types (USERS, GROUPS, and HOST).
    EXCLUDEALL type {name | group_name}
  • Example: EXCLUDEALL the machine with HostName 'sky' from checking out any license features on the vendor daemon on the current license manager.


  • Reserve licenses for a USER, HOST or GROUP of users or hosts.
    RESERVE number feature type {name | group_name}
  • Example: RESERVE 1 license of 'lum_fdtd_gui' for USER 'jill'.   
    RESERVE 1 lum_fdtd_gui USER jill


  • Specify the expiration date of the license to be reserved to a predefined user/host or group of users/hosts.
  • Example: RESERVE 1 license of 'lum_fdtd_gui' with expiry date 31-jan-2022 to GROUP 'grp1'.  
    RESERVE 1 lum_fdtd_gui:EXPDATE=31-jan-2022 GROUP grp1

Note: Ensure that the 'FEATURE' and 'EXPIRY DATE' are identical to that in the license file.


  • Specify the account name of the license as shown on the license details. (use quotes to define feature and account)
  • Example: RESERVE 1 license of 'lum_fdtd_gui' to customer numer 8888888, for GROUP 'lab1'
    RESERVE 1 "lum_fdtd_gui:VENDOR_STRING=customer:8888888" GROUP lab1

Note: Ensure that the 'FEATURE' and 'VENDOR_STRING' are identical to that in the license file.


  • Sets the time after which an inactive license is freed and reclaimed by the vendor daemon.
  • Minimum timeout is 7200 secs (2 hours)
    TIMEOUT feature{:keyword=value} seconds


  • Same as TIMEOUT, but applies to all features. 


User reservations

The following will reserve one FDTD GUI and two FDTD solve licenses for the USER named 'bill'.

RESERVE 1 lum_fdtd_gui USER bill
RESERVE 2 lum_fdtd_solve USER bill

Group reservations

The following option file code will reserve 2 FDTD full licenses (GUI and solve licenses) for a group called, 'ResearchLab' that includes 'bob', 'john', and 'tim'.

# Define the members of each group
GROUP ResearchLab bob john tim 

# Define the restrictions/reservations 
RESERVE 2 lum_fdtd_gui GROUP ResearchLab
RESERVE 2 lum_fdtd_solve GROUP ResearchLab

Multiple licenses

Reservations for different licenses

Suppose Group A has a license of FDTD that will expire on January 31, 2022, and Group B has a license of FDTD that will expire on March 31, 2022. The two groups don't want to share licenses, especially after Group A's license expires.

The duplicate product means that there will be duplicate features of 'lum_fdtd_gui' and 'lum_fdtd_solve'. Therefore you have to specify your features using a different keyword-value pair. The following syntax is used.


There are many possible keyword combinations that could be used. In this example, we are using the EXPDATE keyword (the expiry date of the license).  The final options file would look something like this:

# Define the members of each group
GROUP GroupA bob john tim

GROUP GroupB anna suzanne

# Define the restrictions/reservations 
RESERVE 1 lum_fdtd_gui:EXPDATE=31-jan-2022 GROUP GroupA
RESERVE 1 lum_fdtd_solve:EXPDATE=31-jan-2022 GROUP GroupA
RESERVE 1 lum_fdtd_gui:EXPDATE=31-mar-2022 GROUP GroupB
RESERVE 1 lum_fdtd_solve:EXPDATE=31-mar-2022 GROUP GroupB

A different keyword-value pair can be used. Like, ISSUEDSTART or SIGN. These keyword-value pairs can be found in the license file.

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