Only allow users to connect when connected to the VPN

I need a way to make it so that users are only able to connect to the openfire server through the companies VPN. Currently, the VPN uses 10.8.X.X, with 10.8.0.1 being the server. So I need to make it that users can only connect to the server through 10.8.0.1 and not the other “internet” IPs on the server. I am running Gentoo Linux

Thanks…

!0.X.X.X addresses are not available from the internet generally speaking. That addressing scheme is generally intranet only. As long as you do not have ports open on the firewalls you should have no issues.