Consider the following scenario in which two licenses are assigned to the same user. (This can only happen on Windows NT Workstation or Windows NT Server and not on Windows for Workgroups or Windows 95.) A primary domain controller (PDC) has its Guest account disabled. It has a share by the name of LLS and a user with the name DomUser, whose password is also DomUser.
From DomainA, the user connects, in Per Seat mode, to the PDC using the following command:
net use * \\pdc\lls /u:DomUser DomUser
This gets counted as DomainA\DomUser, and one license is assigned.
From DomainB, the user connects via RAS to the PDC using the same command as before. This gets counted as DomainB\DomUser, and another license is assigned.
What has happened is that you didn't specify the domain and so the local account on the PDC is giving you access, but your connection is still from the remote domain. To avoid this situation, the user must specify their domain name along with their username. For example, if you specify the same name from both domains, that is /u:DomainA\DomUser, the PDC will count it as a single connection and assign a single license.
Another solution, if you are using a notebook or laptop computer that is disconnected from the network, is to log on as the domain user account rather than as the local user. Then, if you connect via RAS to the network, you are only assigned one license and not two.