Well, I hope the title explains it somewhat..

Basic Idea,
we'd like to upgrade a site to 7.1 from 6.5,
Im quite certain that the upgrade/install part wont be any issues
since it's a dedicated NW65/sp6 server running the zen stuff,

But,, the clients/agents.
Will those have to be updated immidiatly or will they keep working
with the older 6.5 agent installed ??

What we need to do quite soon is the upgrade from a server standpoint
since we are merging in another tree which has zen 7.1.

But,, we would prefer not to have to update all clients/policy's etc
in the central location if possible in the short term. More or less
just update the server and hope/think that things keep running "as is"

Is this possible/believable ?