We are doing a complete server and infrastructure update with a Migration from Exchange 2007 to 2010. Along with the server upgrade we're doing a migration from an old antiquated 192.0.2.x internal class c to 10.x.x.x internal class a. At this time my Exchange server is at 10.0.1.5 and my Wireless and VPN is still issuing 192.0.2.x IPs. All of my Outlook and Droid users are being routed properly from 192.0.2.x to 10.0.1.x, connecting to the exchange server no problem. My iPhones (running iOS 6.1.3) on the other hand just will not connect. No matter what I try to change in settings, whether on wireless or through the VPN, I keep getting "Connection to the server has failed." Also when setting the server (IP or DNS) I get a "Cannot verify server, do you want to continue." I've tried SSL on and off. I've tried domain\username and just username. I've double checked the password multiple times. I've tried IP address and DNS name for the server. Nothing seems to work.
Does the iPhone have problems crossing subnets even if they're routed property? Does v6.1.3 have problems with Active sync? Anything?
EDIT: I've tested the iPhones on wireless and through the VPN to the Exchange server's OWA in Safari. That works perfect all around.