Going to try and explain this the best I can..
I have 2 public IP addresses. my cisco asa is configured with a NAT that assigns my exchange server 1 of the IPs, everything else gets the other IP.
I have exchange 2007, win2k8ex1 which has a NAT rule inside a cisco ASA that translates all communication through a static public IP (well say x.x.x.1)
I then have my domain controller with all the other systems that use x.x.x.2
I am currently upgrading to exchange 2010, on the inside everything is fine, I havent migrated mailboxes or anything yet. But I set up the legacy, autodiscovery, mail, and owa records accordingly on the inside dns (legacy is the only thing that points to exchange07) and it works fine.
I wanted to migrate users in groups over the next week.
Looking at the ASA, is it possible to have both of these servers talk through the same public ip using the NAT rules? I can only configure it to use one server at a time on the exchange-outside-ip (x.x.x.1)
im hoping i explained this well enough