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How to tell MDT where the network license server is?

Updated on 3 September 2026 tcpMDT

Summary

When MDT works with a network license (a USB dongle or a software key installed on a server), every client computer needs to know which machine on the network holds that protection. This article explains how to indicate the location of the license server at each workstation, either with the MDT server configuration command (for example mdt9_servidor) or from the license manager panel of the computer itself (http://localhost:1947/ with Sentinel LDK, http://localhost:6002/ with the older protection); how to force a specific server when the automatic broadcast search is slow or fails to find it; which ports must be open; how to reach the license through a VPN; and why a network license stops working outside the organisation's network (the "board not found" error).

Applies to

MDT with a network license (LDK / network USB dongle or software key on a server).
Versions cited in the documented cases: MDT 9 and MDT 25.
MDT 26 (current version): the network license procedure and how to indicate the server are described in the MDT26 installation manual.
CAD programs in the documented cases: ZWCAD (2023, 2024, 2025) and AutoCAD / Civil 3D (2024; queries also about 2026).

Version and CAD compatibility. According to the documented cases, MDT 9 is compatible up to AutoCAD / Civil 3D 2025. To find out which CAD versions your MDT version supports, check the system requirements in the installation manual; MDT 9 does not run on AutoCAD 2026.

Symptoms

MDT is installed or updated on a new computer (or on several AutoCAD/ZWCAD installations) and has to be pointed at an existing network license.
The installer provided does not match the CAD version in use and the installation does not work.
A remote computer connected through a VPN reaches the CAD license but cannot find the MDT network license.
The automatic broadcast search for the license server takes a long time or does not find the right server, forcing a manual configuration every time the CAD is opened.
After a period without using the program, reinstalling it produces the error message "board not found".
Doubts about which ports to open between the clients and the license server, or about whether the protection driver has to be installed manually on every client.

Cause

The client computer has not been told the location (IP or name) of the server that holds the MDT network protection.
The installed program version is not compatible with the CAD version in use, or the installer does not match the license type (network) or the CAD version.
The broadcast search does not find the right server on the customer's network.
A network license only works when connected to a computer inside the network where the protection is: outside that network (a home computer, for instance) the protection is not detected, which produces the "board not found" error.

Solution

Case: installing MDT on a new computer and pointing it at the network server

Download and install the MDT installer that matches the license type (network) and the CAD version in use. If the link provided does not match your CAD version, ask support for the right installer.
Start the CAD with MDT and, in the CAD command line, run the server configuration command of the installed version. For example, mdt9_servidor for MDT 9.
In the window that appears, choose the fixed server option and enter the IP of the computer that has the network protection connected.
Close and reopen the CAD so that the configuration is applied.

Case: forcing a specific server and avoiding the slow broadcast

If, when opening the CAD, the automatic broadcast search takes a long time or does not find the right server (and a message says the server cannot be found), force the server manually on each client computer:

Open the license manager panel on that computer: http://localhost:1947/ with Sentinel LDK, or http://localhost:6002/ with the older protection. Go to Configuration > Access to Remote License Managers.
Turn off the "Broadcast Search for Remote Licenses" option.
In the "Remote License Search Parameters" box, type the IP of the license server or its DNS name (if it resolves correctly).

Case: reaching the network license through a VPN

For network (LDK) licenses it is indeed possible to reach the license server through a VPN. On every computer where MDT is installed you have to indicate the location (name or IP) of the license server, as described in the installation manual (the section on how to specify where the license server is). The procedure is the same as in the cases above (mdtN_servidor or the license manager panel of the computer).

Case: identifying the server by DNS name instead of IP

The license server can be identified by a DNS name instead of a fixed IP address, as long as that name resolves correctly to the server IP. Enter the DNS name in the same place where you would enter the IP (the server command or the "Remote License Search Parameters" box of the license manager panel).

Case: network ports required

Both the ports to open and the address of the management panel depend on the generation of the protection:

	Sentinel LDK (keys later than September 2023 and software licenses)	Older Sentinel protection (keys earlier than September 2023)
Port to open on the license server	1947, TCP and UDP	6001 UDP
Management and license viewing panel	`http://localhost:1947/`	`http://localhost:6002/`

Ports. Open and allow traffic through the corresponding port on the computer acting as the license server.

Management panel. The address is opened on the computer itself from which you want to check the licenses, be it the server or a client workstation: that is why it is localhost and not the server IP.

If you do not know which generation your key belongs to, ask support, indicating its serial number.

Case: "board not found" error with a network license

This message appears when the computer does not detect the network protection:

If you are inside the corresponding network and the connection with the protection has been lost, start the CAD, run mdt9_servidor and enter the IP of the computer where the network protection is. Close and reopen, and check whether the software works normally.
If you are trying to use the program outside that network (on a home computer, for instance), bear in mind that a network license only works when connected to a computer inside the network where the protection is. To work outside that network, the option is to install an evaluation version.

Case: does the protection driver have to be installed on every client?

There is no need to install the protection driver manually on the client computers. The driver installer is available in the program installation folder of any computer where MDT is installed (the server, for example), but the MDT installer itself takes care of installing the required drivers and runtimes on each computer. The paragraph in the manual about installing the Sentinel LDK runtime refers to the server computer where the key or the software license is placed, not to every client.

If the problem persists

If you do not know which type of license you have (software or hardware key, online/offline activation, network license), confirm it with APLITOP technical support, indicating your license number.
To download the most recent version of the program, go to your private area with your user name and password, or use the MDT menu: Utilities > Support > Available updates, and click on the license to see the existing updates.
If the problem continues after indicating the server, contact APLITOP technical support, indicating your license number and the MDT and CAD versions installed.

Category: Network licenses and hardware protection · Level: Intermediate