achinoam01: Maintaining a Dynamic DNS automatically.

Sunday, September 4, 2011

Maintaining a Dynamic DNS automatically.

Dynamic DNS services provide you with a domain name you can use with a non-static IP address, like most home computers have. To use these requires some action to periodically contact the DNS server and let it know if your Dynamic IP address changed. Usually there are complicated scripts provided to do this, and MacOSXHints has published a few.

However one can greatly simplify this with a launchDaemon and a single built in OSX unix command.

First, this assumes that you have set up an account with a Dynamic DNS service. I use the free service provided by FreeDNS. One updates this simply by loading a web page URL. The act of making that page request alerts the DynamicDNS of your IP address and it updates.

Thus all we need is a LaunchDaemon that runs every hour that reloads that page. Here is an example: ...