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If you want more than two virtual machines, then you have to add a new Network adapter configuration in /etc/sysconfig/network-scripts and add a new line in all the hosts files.
Centos 7 like Windows has a built in Firewall that might be useful on a desktop machine. In a private virtual network it is useless, and it has been disabled by telling the OS to not start the firewall service ("systemctl disable firewalld"). If you reenable it, then you have to open port 40001 for Ehcache and other ports like 8080 for JBoss.
Clone
The Sandbox VM can be cloned to produce a second CAS VM for testing cluster failover.
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Every time you create the clone, before starting the clone VM you edit the LAN adapter to change the MAC address from one ending in AD to AE, and after starting the clone for the first time you issue the hostnamectl command as described above to change the hostname. The rest should take care of itself.While you are free to try and configure the firewall yourself, there is no need for a firewall in a walled off private network. It is disabled in the Sandbox VM ("systemctl disable firewalld").
CAS Development
CAS development is the same whether you are working on a Windows host computer (with Eclipse and JBoss) or on the Sandbox VM. You edit in Eclipse, build with Maven, and run JBoss from the Eclipse toolbar. Generic CAS develpment is described elsewhere. This section just describes the Sandbox.
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