After MUCH research and reading I still cannot find the straight and simple way to secure my elastix box. All I want to do is to block all access from the internet to the elastix box EXCEPT for the a2billing directories. I do not want to block anything from the local LAN. The best I can see is to use IPTABLES but I cannot find any examples on how to block everything except for some directories on a server from WAN access. Any guidance in this area would be greatly appreciated!