Requirements

1. BIND DNS server daemon
2. Some HTTP web server
3. PHP

Server side installation

Create DNSSec key

Log into your server as a root and generate a new key for your DNS updater:

dnssec-keygen -a hmac-sha512 -b 512 -n HOST dyndns.example.com.

This will create two files starting with letter K, then your domain name, then some gibberish and ending with .key and .private. Get the key value from .key file:

cat Kdyndns.example.com*.key

this will output something like this:

dyndns.example.com. IN KEY 512 3 165 bwfb5O8+1VUiV3un66ucV1c9yAyT5Hdzs1gUHpcWWZrFEihtLlKl1E4E wFsTNbWg+EvK/ddOq7wWmZ9GYaPYbw==

Copy the Base64 part from the key file (the one that looks like: bwfb5O8+1VUiV3un66ucV1c9yAyT5Hdzs1gUHpcWWZrFEihtLlKl1E4E wFsTNbWg+EvK/ddOq7wWmZ9GYaPYbw==) The space in the key is OK, don't worry.

Create zone configuration

Open up named.conf in your favourite text editor and add your zone configurations:

key "dyndns.example.com." {
    algorithm hmac-sha512;
    secret "bwfb5O8+1VUiV3un66ucV1c9yAyT5Hdzs1gUHpcWWZrFEihtLlKl1E4E wFsTNbWg+EvK/ddOq7wWmZ9GYaPYbw==";
};
zone "dyndns.example.com" {
    type master;
    file "/path/to/your/zones/dyndns.example.com";
    allow-update { key "dyndns.example.com."; };
    notify yes;
};

Create zone file

Now create a zone file and update accordingly (add your NS and primary A records, update SOA record):

$ORIGIN .
$TTL 7200               ; 2 hours
dyndns.example.com      IN SOA  ns.example.com. hostmaster.example.com. (
                                2014010101 ; serial
                                3600       ; refresh (1 hour)
                                900        ; retry (15 minutes)
                                604800     ; expire (1 week)
                                3600       ; minimum (1 hour)
                        )
                        NS      ns.example.com.
                        NS      ns2.example.com.
                        A       123.456.789.012
$ORIGIN dyndns.example.com.

Reload your DNS server with:

rndc reload

and probably check your log files if everything went on smoothly.

Create a webservice

Create a virtual host in your favourite HTTP server and install all the server side scripts into your desired virtual host. Update your configuration files accordingly:

• copy the config.inc.php.sample to confing.inc.php and edit it's contents
• copy the clients.inc.php.sample to clients.inc.php and add your clients

Test your updates through provided update form.

Client side installation

Place your files somewhere on your client server/computer. Update your configuration files accordingly:

• copy the config.inc.php.sample to config.inc.php

Test your updates by launching the client:

php updater.php

Copy the updater.cron.sample to updater.cron, edit it accordingly and add your updater script to crontab:

crontab updater.cron

Voila!