Hello. I have a web server with Ubuntu Server 12.04 and ISPconfig 3.0 installed. I have a dedicated ip address(with pppoe connection) and untill now all my services are working fine: apache2, mysql, pureftpd, postfix. I have almost 50 websites hosted on this server. All is working fine but i want to change my ISP and my ip address also. What files should i have to modify so that all my websites hosted until now on my server to not be affected. Thanks in advance.