Exchange, Firewalls, and Support… Oh, my!
Over the years Exchange Server architecture has gone through a number of changes. As a product matures over time you may see us change what is supported as we react to changes in the product architecture, the state of technology as a whole, or major support issues we see come in through our support infrastructure.
Over the years a large volume of support calls have ended up being caused by communication issues between Exchange servers or between Exchange servers and domain controllers. Often times this results from a network device between the servers not allowing some port or protocol to communicate to the other servers.
Read the complete blog at https://blogs.technet.com/b/exchange/archive/2013/02/18/exchange-firewalls-and-support-oh-my.aspx
Read my favorites blogs:
Designing a backup less Exchange 2010 Architecture
Microsoft Exchange 2010 CAS Array – Steps and Recommendations
Appear Offline in Microsoft Office Communicator Server 2007
Microsoft Exchange 2010 Test cases