Relay cannot communicate with Endpoint.
Gateway To MAG fails for "NoRouteToHostException: No route to host"
Endpoint firewall may be disallowing traffic. Disable firewall to see if problem goes away.
>> service firewalld stop [ or if iptables - >> /etc/init.d/iptables stop ]
If disabling firewall does fix the problem then have client make the changes permanent. Or make sure firewall is enabled and re-run installer - this will set the rules properly. In fact, the root cause here is that the installer was likely run with the firewall stopped. Then the firewall was turned on after install.