Tutorials

How to activate a network license in AutoCAD? (Solved)

Many people need a clear, step-by-step guide to activate a network license in AutoCAD. This article gives a practical, beginner-friendly walkthrough: preparation, installation of the Autodesk Network License Manager (NLM), configuring the server, connecting clients, troubleshooting common errors, alternative methods, and useful tips to keep your network licensing stable and secure.

Intro — what is a network license and when to use it

A network (floating) license lets multiple users share a pool of AutoCAD licenses over your local network. It’s ideal for teams where not everyone needs AutoCAD at the same time. The license is hosted on a license server (using Autodesk’s Network License Manager, aka FLEXnet) and clients “check out” a seat while using the software.

Key benefits:

  • Cost efficiency: fewer licenses needed for larger teams.
  • Central control: manage licensing from one place.
  • License borrowing: allow temporary offline use.

Prepare before activation

  • Confirm you have a multi-user (network) license entitlement from Autodesk. Check your Autodesk Account for serial numbers and license type.
  • Choose a dedicated server (Windows or Linux) with a static IP or a stable hostname.
  • Obtain the server machine’s Host ID (MAC address) — Autodesk requires this to generate a network license file.
  • Make sure you have administrative rights on the server and client machines.
  • Temporarily disable or configure firewall/antivirus to allow license server ports. (See firewall section below.)

Step-by-step: Install and activate the Autodesk Network License Manager (NLM)

1) Download the Network License Manager

  • Log into your Autodesk Account > Products & Services > find AutoCAD > under downloads look for Network License Manager (NLM) for your AutoCAD version.
  • Download the NLM installer for your server OS.

2) Get the license file from Autodesk

  • In Autodesk Account, go to All Products & Services > choose your product > Manage License or Request License File.
  • Provide the server Host ID (MAC address) and server name. Autodesk will produce a .lic license file or instruct you to activate online to create that file.
  • Save the license file (it contains lines starting with SERVER and VENDOR).

3) Install NLM on the server

  • Run the NLM installer and install to the default folder (e.g., C:\Program Files\Autodesk Network License Manager\ on Windows).
  • Copy the downloaded .lic file into the NLM folder.

4) Configure and start the license service (Windows example)

  • Open LMTOOLS.exe (included with NLM).
  • Under the Config Services tab:
    • Service Name: choose a meaningful name (e.g., Autodesk_NLM).
    • Path to the lmgrd.exe and the vendor daemon (adskflex) should be auto-filled by installer.
    • Specify the full path to your license file (.lic).
    • Optionally set a log file path (enable debug logging if troubleshooting).
  • Save the service configuration.
  • In LMTOOLS, use Start/Stop/Reread tab to Start Server.
  • Use Server Status > Perform Status Enquiry to verify the server and vendor daemon (adskflex) are running and that license features are present.

5) Allow license server ports through firewall

  • Open TCP ports 27000-27009 (FLEXnet default range) and 2080 (common vendor daemon port for adskflex). Some setups use just 27000 and 2080; check your license file for port specifics.
  • On Windows: add inbound rules in Windows Defender Firewall for lmgrd.exe and adskflex.exe and/or the above port range.
  • Ensure network devices (routers, switches) do not block these ports between clients and server.

6) Configure clients to use the network license

Several ways to point clients to the license server:

  • Method A — Environment variable (recommended):

    • Create an environment variable on client machines named ADSKFLEX_LICENSE_FILE with value @server_name or @server_IP (for example: @licenseserver or @192.168.1.10).

  • Method B — AutoCAD Licensing dialog:

    • In AutoCAD, go to Manage License or the licensing dialog and choose Use a network license, then enter the server name.

  • Method C — Registry or deployment configuration (for large deployments use the Autodesk deployment tool to set the license server during MSI deployment).

  • Launch AutoCAD on the client to verify it checks out a license seat. In AutoCAD, use Help > About > Product Information > License Information (or similar) to confirm.

Alternative methods and scenarios

  • Cloud / Named-User Licensing: Modern Autodesk subscriptions often use Named User (cloud-based) licensing tied to Autodesk accounts. If your subscription is Named User only, you cannot use a network license — sign in with your Autodesk ID.
  • License borrowing: Clients can borrow a license for offline use. In AutoCAD: choose Borrow License (or use the Autodesk License Borrow utility) and select duration.
  • Virtualized servers: If hosting NLM in a VM, ensure the Host ID (MAC) used to generate the license matches the NIC that will remain stable. Some cloud-provided MACs may change—use caution.
  • High availability: For redundancy, Autodesk recommends separate license servers with careful management (you cannot typically pool one file across multiple machines; check Autodesk’s guidance for failover strategies).

Common errors and fixes

  • Error: “License server machine not found” / “Unable to connect to license server”

    • Fixes:
      • Verify server is running (LMTOOLS > Server Status).
      • Use ping and nslookup to ensure server name resolves to correct IP. If DNS unreliable, add server name to client hosts file (C:\Windows\System32\drivers\etc\hosts).
      • Use @server_IP in ADSKFLEX_LICENSE_FILE to bypass DNS.

  • Error: “Vendor daemon not running” (adskflex)

    • Fixes:
      • Check license file path and permission.
      • Ensure adskflex.exe exists in NLM folder.
      • Inspect the debug log for errors (set in LMTOOLS).
      • Restart the service or server and check Event Viewer.

  • Error: “No available licenses” / “License Checkout Failed”

    • Fixes:
      • Confirm the license file includes the product feature you’re trying to use.
      • Check current usage with lmutil lmstat -a -c [license_file].
      • If seats are exhausted, consider adding more seats or reclaiming borrowed licenses.

  • Error: “Feature not found in license file”

    • Fixes:
      • Ensure the license file corresponds to the AutoCAD version and product (e.g., AutoCAD vs AutoCAD LT).
      • Contact Autodesk support to request the correct feature set.

  • Error: “License file expired”

    • Fixes:
      • For subscription licenses, ensure your subscription is active in Autodesk Account.
      • Request an updated license file or renew subscription.

  • Error: Firewall / Port blocked

    • Fixes:
      • Open TCP ports 27000-27009 and the vendor daemon port in server firewall. If in doubt, open a narrow rule for lmgrd.exe and adskflex.exe.
      • Confirm no intermediate network firewall blocks those ports.

  • Error: “Host ID mismatch”

    • Fix:
      • The Host ID used to create the license file must match the server NIC MAC addressed in the file. If server NIC changed, request a new license file from Autodesk.

Useful commands and tools

  • LMTOOLS.exe — GUI to configure and manage NLM (Windows).
  • lmutil lmstat -a -c [license_file_or@server] — shows license server and usage details.
  • Check logs in the NLM folder (lmgrd.log or custom log specified in LMTOOLS).
  • Windows Event Viewer for service-related errors.
  • Autodesk Knowledge Network and support portal for version-specific troubleshooting.

Tips for stable network licensing (best practices)

  • Use a dedicated and stable server with a static IP.
  • Keep a backup of your .lic license file and NLM configuration.
  • Set up regular monitoring: check user counts and license usage peaks to plan purchasing.
  • Document server name, host ID, and serial numbers in a secure location.
  • Use LMTOOLS automation scripts to restart the service on server reboot.
  • If deploying to many clients, use Autodesk’s deployment tools to automatically configure ADSKFLEX_LICENSE_FILE.
  • For remote workers, use borrowing instead of exposing the license server to the public internet.
  • When upgrading AutoCAD versions, check compatibility between the NLM version and the new AutoCAD — update NLM if required.

FAQ

How do I check how many licenses are currently in use?

Use the command: lmutil lmstat -a -c @your_server_name (or run Server Status – Perform Status Enquiry in LMTOOLS). The output lists features, total licenses, and current checkouts.

Can I use a network license over the internet for remote users?

Directly exposing your license server to the internet is not recommended for security reasons. Use license borrowing for remote users or a VPN so clients access the server over a secure tunnel.

My license file was created for a different AutoCAD version — what should I do?

You need a license file that includes the correct feature names for your version. Contact Autodesk support or re-generate the license file in your Autodesk Account specifying the correct product/version.

How long can I borrow a license and how do I return it early?

Borrowing duration varies but is typically up to 90 days depending on your license. Borrow and return via the Borrow License option in AutoCAD’s License Manager. To return early, use the same dialog on the client and select Return License.

Do I need to update the Network License Manager when installing a new AutoCAD release?

Often yes. New AutoCAD versions may require a newer NLM. Check Autodesk release notes and download the latest NLM for the AutoCAD version you are deploying.

What information do I need to request a license file from Autodesk?

You need the serial number / contract information, the server hostname, and the server Host ID (MAC address). Provide these in Autodesk Account when requesting or activating network licenses.

Who should I contact if the license file is corrupted or missing features?

Contact Autodesk Support with your serial number and server Host ID. Keep copies of prior license files and any purchase documents to speed up support.

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