I'm looking to upgrade my Zen 4.01 to zen 6.5 and I'm a little unclear
on something. My 4.01 is on an older 6.x server. It's the last service
running on that server and when it's gone that server will be taken out
of service.

What I would like to do is install Zen 6.5 on the new server, and then
take 4.x out. I'm unclear however as to how this will work? Which
server winds up handling everything when you have 2 on the same network?
I'm concerned about a fight for control so to speak.