Exchange 2010 with Server 2008 R2 on all servers behind Cisco ASA 5510 environment.
My only experience installing Exchange is limited to a Typical installation where all roles are installed on one server, ie small environments. I'm setting up a new environment consisting of three servers:
exch1 - Mailbox role
cas1 - Hub/CAS role
cas2 - Hub/CAS role
For a single server setup, I would normally just create an external A record for mail.domain.com, a CNAME record for Autodiscover pointing to mail.domain.com, and MX records pointing to an inbound host (ie Postini, MXLogic, FOPE, etc). How does the A record work for environments with multiple CAS servers? Specifically how is the firewall configured? Generally I would just configure an ACL for the WAN IP on ports 25 and 443, then configure a static NAT to my single Exchange server; however, in my current setup with multiple CAS servers, how is the NAT configured?
I've been researching my CAS array options, but I'm still a little confused on the process because I've found conflicting info when asking The Google. Here are the sites I've used thus far:
The list goes on...
I have to say upfront that I am not very well versed with firewalls and know only the basics to allow for my Exchange connections. Any detailed assistance would be greatly appreciated. Thanks!