Some quick caveats regarding network connectivity. It goes without saying that network connectivity is required. There are, however, a couple of items that can cause issues or confusion in this area, either during the installation of the operating system or during the installation of the Messaging Server.
The issues tend to fall into one of five areas within networking:
Host Name Resolution With /etc/hosts and DNS
Naming Services Setup and Best Practices
Network Load Balancing
You can do two things to avoid problems.
First, put all critical hosts that are absolutely, positively required for operation into the /etc/hosts file. Second, put the fully qualified host name ...