[ale] How can I determine my own dynamic IP domain name?

[John M. Mills]

When I establish a PPP link, I recieve an IP name which ranges over
gtri-[1 .. n].remote.gatech.edu and I would like a simple script to extract
that domain name so I could pass it in scripts to remote hosts.
For example I want a script to fill in <my_local_host_name> to do:
  % rsh -l <me> <remote_host> xterm -display <my_local_host_name>:0 &

I expect I could parse the return of 'netstat -t' but if anyone has a
neater suggestion that would be nice.  

Local HOSTNAME of course doesn't reflect the dynamic IP slot I received.  It
stays at <my_git_logname>.remote.gatech.edu.

TIA,

John M. Mills, Senior Research Engineer   --   john.m.mills at gtri.gatech.edu
   Georgia Tech Research Institute, Georgia Tech, Atlanta, GA 30332-0853
        Phone contacts: 770.528.3258 (voice), 770.528.7083 (FAX)
        EMACS: 'Eight Megabytes And Constantly Swapping' -- anon