Re: multimple domain authentication

I'd suggest that the caller's IP address is just a hint, a default or
last resort of where to look for the caller's auth server.  There
probably ought to be a way for the caller to specify an auth server to
be used by the called system to authenticate the caller.  I don't know
if there's existing machinery that can do this or not.  Arguably, "cpu
-u andrey-7EzO+0SSANouExZ/[email protected] -h 9grid.lanl.gov" could be interpreted as
`contact auth.ucalgary.ca to authenticate me as user andrey', for
instance.