Unfortunately there is no way to disable this feature, however as long as the system is updated with a new server address, it should not cause the license checkout to fail. To override the .flexlmrc license source definition, define an IDL_LMGRD_LICENSE_FILE system environment variable that points to the desired license file or server location. Note that even if a system environment variable named IDL_LMGRD_LICENSE_FILE is defined, the IDL_LMGRD_LICENSE_FILE setting in the .flexlmrc file will continue to be referenced, but as a secondary license source if the IDL_LMGRD_LICENSE_FILE system environment variable does not supply a viable license source for the IDL session.

Aha! We have been defining an environment variable named "LM_LICENSE_FILE", for this and at least one other product managed by FlexLM. We concatenate the definitions when additional products are called up by the user. In our previous experience, the value in ".flexlmrc" either did not change, or APPended our new license definition to the previous definition. Thus, users remained loyal to the old license server until we shut it off :-) or until we forcibly deleted their .flexlmrc files. I just updated my own environment to define "IDL_LMGRD_LICENSE_FILE" instead of the generic env var. I called up IDL via the "old" definition, then again via the "new" definition, and am happy to see that the new definition is PRE-pended in the .flexlmrc file, so the new server will always be asked first. This means that I will indeed be able to switch user loyalty without them even noticing. Thanks! I bet this is buried in the license instructions fine print (correct name of environment variable), but when you've been managing a product for a while, it's easy to assume that whatever someone set up years ago is still valid.