DDDNS - Delegated Dynamic DNS - ensures that if your dynamic DNS name resolves, then it is because your server is present (i.e. dialled out or connected). This is done by delegating a DNS sub-zone to your current IP address. If your server is not present, or if another server has taken your former IP address, the name does not resolve.

Audience: System admins for wireless and ADSL users. Dial-up users may be interested too.
System requirements: bind 9, nsupdate and `host'. netdate is recommended if you are not keeping your clock in sync with ntpd
Language: bash
Source license: GPL
You can find the old page for DDDNS here.

Incredibly brief technical details

Dynamic DNS (DDNS) is a well-worn technique for associating a DNS name with a dynamic IP address, usually ADSL, but occasionally dial-up as well. With DDNS, what happens if your machine is not connected for some time? A person visiting your web site may see another site. Mail to your domain may be rejected with a rude message, or, even worse accepted.

DDDNS allows you to run a web site and mail server on a dynamic address with the assurance that if your link is down your name will also be down. Having a reliable DNS name means that you can do all the things you should require a static IP address for:

Miscellaneous implementation notes:


We have included our failover scripts to handle multiple simultaneous pppoe connections. This was written to overcome the 3GB traffic quota offered in South Africa (this problem is a little dated): There are a number of complications that the scripts take care of -


Links to download: You can verify that you have original bugs by checking the signature:
gpg --keyserver subkeys.pgp.net --recv-keys E3572642
gpg --verify *.gz.asc *.gz