I am trying to implement ejabberd clustering on Amazon EC2 instances, I have installed ejabberd and it is working fine on both instances, I can connect and send message, my first server is a master server and has the FQDN of master.example.com, second server is a slave and has FQDN of slave.example.com. I have edited the ejabberdctl.cfg file on both instances changed INET_DIST_INTERFACE on both instances to the value returned by ifconfig changed ERLANG_NODE to [email protected] on master and [email protected] on slave. Now when I run this command on slave net_adm:ping('[email protected]'). it always returns pang response indicating that it can't reach the master server. I am looking for possible fixes for that. Things already done Both master and slave domains are pointing to their instances I even tried allocating elastic ip and assigning that to instances, but did not help either. Any help will be greatly appreciated.