You can define your license servers by using the <port>@<host> function. This method is not constrained by architecture because a license server defined by <port>@<host> communicates directly to the ESRI daemon through the specified TCP/IP port, working around the limitation of architecture specific license files.
Setting an environment variable (eg. ESRI_LICENSE_FILE) enables the <port>@<host> functionality. This variable is set in a client's environment, not on the server side. Both <port> and <host> are found in the SERVER line of your license file. The TCP/IP <port> is indicated at the end of the SERVER line. The host name, <host>, is the second item listed in the SERVER line.
Additionally, <port>@<host> can be abbreviated as simply @<host> as long as the port number in the license file falls within the range of 27000 through 27009 (inclusive).
One advantage of using the <port>@<host> method for defining your license server is the disk containing the license file need not be shared as the lmgrd daemon is recognized on the network through the predefined TCP/IP port. This is significant on Windows NT/2000 because the license manager is installed on the <SystemDrive>, which is normally the root partition, a partition most system administrators do not want shared for security reasons.