Restrict to initial NAS used to logon

["Tuc at T-B-O-H.NET" <ml@t-b-o-h.net>]

Hi,

	Looking to restrict a user to only be able to log in
and re-log in to the initial NAS they first ever logged onto.
(Hotspot)  Looking at the radacct file where it looks like
the check-items normally go against, I'm not seeing anything I
can use as an identifier. The nasipaddress is always 0.0.0.0.
Maybe calledstationid, except if we swap equipment out during
the lifetime of a users id it won't match. 

	Is anyone doing anything like this already?

			Thanks, Tuc