About Network License Server Models

Differences between single, distributed, and redundant license server models.

Autodesk supports three license server models. Each model works differently with the Autodesk Network License Manager (NLM), the tool for managing your network licenses.

• Single license server model. When NLM is installed on a single server, license management and activity are restricted to this server. A single license file records the total number of licenses available on the server. The advantage of this model is that it requires only one point of administration and has only one potential point of failure. The disadvantage is that if the single license server fails, products can't run on any computer in the network until the server is back online.
• Distributed license server model. With this model, licenses are distributed across more than one server, with a unique license file for each server. NLM runs on each server. This server model has several advantages:
  • You can distribute license servers across a wide area network (WAN) to support users in different locations. The servers don't need to exist on the same subnet.
  • If one server in the distributed server pool fails, the licenses on the remaining servers are still available.
  • If you have to replace a server in the distributed server pool, you don't need to rebuild the entire pool.
  • Server replacement is easier than in a redundant server pool, where you must reactivate the entire pool.

  The disadvantage of this server model is that it requires more time for setup and maintenance than the other models.

• Redundant license server model. With this model, three servers are available to authenticate each license, because the same license file is stored on all three. Licenses continue to be monitored and issued as long as at least two of the servers are functional. NLM runs on each server. The advantage of this server model is that if one of the three servers fails, all licenses in the server pool remain available. It has several potential disadvantages:
  • If more than one server fails, no licenses are available.
  • All three servers must reside on the same subnet and have reliable network communications. The redundant server pool does not provide network fault tolerance.
  • If you replace one of the three servers, you must rebuild the entire redundant server pool.