I'm interested in blocking a service from running outside of the LAN except to myself. Since my ISP uses a dynamic IP I use no-ip to give myself a static name I can use to SSH into my system. For those unaware, no-ip.com offers a client service that runs on your system and updates there DNS servers anytime your IP changes. You can register for a surname.no-ip.com or from a selection of others as a way to run a website off a dynamic IP system. This also works with VNC, SSH, etc. I was thinking if I can put surname.no-ip.com as an allowed IP in my server's xinetd directory for SSH, VNC, etc. only my home PC can get to SSH from outside the network no matter what my IP address changes to. Would this work? How can I write this? I was thinking I can put in a cron job on the server to get the IP of surname.no-ip.com on a set interval (say 15 minutes) and parse it to a string or environment variable so that in the file I could write $adminip and it would check against it's system.