The rules about FLEXnet licensing server version compatibility.

Below are the basic rules governing the compatibility of FLEXnet Licensing:

The Version of lmutil/LMTOOLS must be greater than or equal to the version of lmgrd, which must be greater than or equal to the version of the vendor daemon (telelogic), which must be greater than or equal to the version of the client library linked to the FLEX enabled application, which must be greater than or equal to the version of license file format.

When viewed hierarchically:

Version of lmutil/LMTOOLS must be >=

      Version of lmgrd, which must be >=  

            Version of vendor daemon (telelogic), which must be >=

                  Version of the client library linked to the FLEX enabled application, which must be >=

                        Version of license file format

In the above, we can see that the license server executables (lmutil/lmtools) must be at the latest and greatest level to support serving licenses for any prior versions to ensure backwards compatibility.