This script can be used to autmatically update the DNS entries of one or more domains when a dynamic IP address is changed. This script should be run on the server that the DNS entries should point to. It should not be served by a webserver! That is, don't put this in your htdocs or www folder or whatever.

When you use this script, it is advisable to set the Time To Live (TTL) of your DNS records to 1 hour to limit the amount of downtime when the address changes.

1. Requirements: Python 3.x and the cryptography and requests packages (run: pip install cryptography requests).
2. Go to the TransIP Control Panel at https://www.transip.nl/cp/account/api/ (Account > API) and enable the API. Add a key pair to generate a private key, this must be generated without the "whitelisted" option! (After change to un unknown dynamic ip, this new ip is not in the whitelist!)
3. Copy-and-paste the generated private key into the definition of PRIVATE_KEY in the dyndns.py script.
4. Change the definitions of LOGIN and DOMAIN_MAIN_ENTRY to match your TransIP username and domain name(s). If you are going to have multiple servers logging into the same TransIP account, also make sure the value of LABEL is unique to avoid clashes.
5. Change access to the script file, so it can't be accessable from outside. You don't want to leak your details!!!
6. Call dyndns.py script on the command line whenever you want the DNS to be automatically updated. You can use cron to do this periodically for you.

To enable IPv6 support, you need to add one argument to the command line. This is the current IPv6 address:

 python dyndns.py 2001:db8::ff00:42:8329

Alternatively, you can set the argument to online. In that case, the script will query an online service for the IPv6 address.

 python dyndns.py online

Note that this method may result in a temporary IPv6 address (due to Privacy Extensions). It is therefore highly recommended to supply a stable, SLAAC IPv6 address to this script directly. You can use the following command line to use the current SLAAC IPv6 address from the eth0 network interface:

 python dyndns.py "`ip addr show eth0 | grep -Poh '(?<=inet6\s)[0-9a-f:]+(?=/64)' | grep -vm 1 '^fe80'`"