Spark wont connect to Openfire server without pinging it first

I’m running in to a odd problem. I have Openfire running on CentOS 7 and it works awesome, unless I have to reboot the server and then I have to ping it from each client computer before they can authenticate with the server for some reason. Once I do, it works no problem even if they restart their machine. I can solve this by adding a script to their computer so that it pings the openfire server when it reboots, then just have them all reboot their systems if I have to take the openfire server down for something, but I’d rather have a more elegant solution and fix whatever is causing this. Any ideas as to what could be causing this?

This must be something on the CentOS side, a firewall probably (selinux policies, etc.).