RADIUS server

Apparently we once had a RADIUS server for our VPN authentication. The
guy who set it up, our IT Mgr, kept everything a secret, consequently
no one knows exactly what it was, where it was, etc.

It stopped working last Fall sometime. ( He left last summer. ) We
think it was set up on a virtual machine we didn't know was running
it. This would be, of course, a VM we deleted.

We've found documentation, but it's so... We need a bit of help.
Perhaps some better documentation, a high level overview, whatever. At
the moment we feel rather lost.

Any help, thoughts/suggestions would be appreciated.

Thanks in advance,

Tom