Linux Server Showing down/Not Activated in HC cluster

Question: Linux Server status is showing down/Not Activated, how do I fix it?
Please ensure the following points:

Linux server build should be the same which is running on windows server. Verify this from command: 
          hc9 –version
          If it is different then apply same build on both windows & linux by following this Link.

HC database server IP should be included in hosts.allow file located in /usr/local/hostingcontroller/etc.

Add IP under

If firewall is enabled on windows or linux server then make sure that following ports are allowed in it:
          HC Server port = 8788
          HC Remoting port = 8789 
In Fedora/Centos operating system you can disable built-in firewall by using this command:
         /sbin/chkconfig iptables off
         /sbin/service iptables stop 

On Linux Server, Selinux must be disabled (applies only for Fedora/Centos/Red Hat Enterprise).
          vi  /etc/selinux/config

Restart HC service. 
          hc9 restart