Network or multi-user for Autodesk software is a very good way to control license usage and prevent piracy within your organisation. Previously what you would find is that there would be 3 or 4 computers that were activated with the same serial number which constitutes piracy. This can be alleviated by using network or multi-user licenses.
When you have purchased a multi-user license you can install the software on as many machines as you like. the license server will determine how many concurrent users can use the software at one time.
When opening a network or multi-user license the software will send off a request to the license server to request a license. if there is one available the software will open. If not then it will return an error that normally looks like this. -15.570.0. This is saying that there is no license available or the connection to the server has been lost.
The type of license that is issued depends on the feature code that is present in the license file. There are 3 types of feature codes used in the license file.
Product specific on a maintenance plan (old licensing system) – eg 64300ACD_F. Because there is no version number in this feature code it also tells you that it will activate the current version (2017) and 3 versions back as well because it is on a maintenance plan.
Product specific with multi-user access – eg 64300ACD_T_F. This tells us that it will activate an AutoCAD network license which is the current version (2017) and 3 versions back as well.
The 3rd and final feature codes indicates a specific product and version – eg 86445ACD_2016_0F. This tells us that the software is off maintenance and you can only use the 206 version of AutoCAD.