Re: suggestions for grabbing license from home

["J.D. Smith" <jdsmith(at)astro.cornell.edu>]

Carsten Dominik wrote:
> 
> >>>>> "D" == dmarshall  <dmarshall@ivory.trentu.ca> writes:
> 
> D> Hello all.  I'm hoping to get some troubleshooting suggestions.  At
> D> work I can run IDL 5.2 from my office remotely via a floating
> D> license.  My machine has WIN98 and the server has WIN NT. Things
> D> work fine, if someone is using the license when I try it tells me
> D> such else it fires up properly otherwise.
> 
> I don't have an answer to this - just a question.  I did not know that
> it is legal/possible to run IDL from home using a floating license at
> work.  How is this done?  Would someone care to write a brief summary
> of the steps necessary?  At home, I run RedHat 6.1, at work we have
> HP-UX if that matters.
> 
> Thanks a lot!
> 

The basics of floating licenses are quite simple, actually.  A floating license
server answers queries on port 1700, by default.  The client gives the server
some of the information from its license.dat file (usually exactly the same file
which resides on the server), amounting to the hardware id of the server (3rd
thing on the SERVER line), and the license strings and checks from the relevant
INCREMENT line (e.g. INCREMENT idl for checking out IDL licenses).  If all this
information checks out, and there are still licenses remaining, the client is
granted a license.  

Any client, anywhere, which has this information (i.e. has the license.dat file
corresponding to that server), is granted access, by default.  So if you gave me
your license.dat file, I could check out your licenses from here!  Some sites,
recognizing that the keeping the license.dat file secret is difficult, have put
in place other measures to limit access, by ip address, for example.  This is
not too hard actually, but most people don't do it, since the users are logged
anyway, and so "stealing" licenses probably wouldn't be a sustainable practice.

So the long and short of it: given the license.dat file, you can (usually) check
out licenses from anywhere.  Just drop it in your license directory.  Note that
some site licenses might discourage this kind of usage, so be sure to check out
the policy.  And note that the client checks in with the server every so often
(~5min), so the network link must be maintained.  

As a bonus, Windows and Linux clients only check out 6 licenses, compared to the
10 required to check out a unix license... so you get effectively more of them.

JD

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 J.D. Smith                             |*|      WORK: (607) 255-5842    
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