I had this situation some years ago (though a lot fewer users!). I set up
the new server on the network with its own IP address and name. The weekend
we cut it over to production (and removed the old server), I updated the IP
address to include the old server's address, as well as keeping the new one.
These were internal (10.) addresses, but can't see while it wouldn't work
for "real" addresses - as long as the old server is taken off the network,
or had a different address applied to it.
Jerry C. Adams
IBM i Programmer/Analyst
Being told you're the nicest guy they know is the kiss of death.