Dynamic DNS

Many thanks to my friend who runs the name servers for making this possible.

If you've got a dynamic IP address and want to run your own web server on a domain of your choosing, you've got a problem. You need some way to provide name resolution for your domain and be able to automatically update that information every time your IP address changes.

There are several free services that provide dynamic dns for domains that they own. Generally this means yourhostname.theirdomain.com. If, however, you want name resolution for www.yourdomain.com, you're probably going to have to pay for it.

But let's say you have a couple name servers under your control or otherwise know someone that has name servers that's willing to help you out, you can use those name servers to provide name resolution for your domain.

The problem is this: how do you update the zone files on the name server when your IP address changes? If they're under your control, the process is not too dificult. You need to:

1. Realize that your IP address has changed.
2. Update the zone files on the nameservers (don't forget to change the serial).
3. Make bind on the nameservers reload the zone files.

If the name servers are not under your control, you probably need to:

1. Realize that your IP address has changed.
2. E-mail the administrative contact of the name servers with the new IP address.
3. He/she then makes the changes to the zone files and..
4. Makes bind on the nameservers reload the zone files.

Since both of these scenarios are a hassle and are likely to cause delays in updating your name resolution information, some method of automating this process is obviously necessary.

Originally, I hacked a pair of simple bash scripts to automate the updating process. One script was intended to run on the name server, and the other on the client. More recently, however, my friend (the one that runs the nameservers) developed a cooler script that supports multiple domains. The old scripts have since gone in the dumper.

Here are some of the features of the the DIYDNS scripts:

supports updating multiple domains
secure updates with nameserver
client supports configurable logging

If you want to try it out, simply download the package Simply untar it in a location of your pleasing and read the README file for installation instructions.

If you run into problems, feel free to e-mail me. If I can help, I will.