This simple flask based server allows you to forward the DnyDNS update requests of your fritzbox to the ddnss DynDNS service while adjusting the IPv6 address correctly. This is necessary if you want to publish the IPv6 address of a server and not the fritzbox itself.
The prefered way of running this simple server is to use docker. First, we build the docker image:
$ git clone https://github.com/seeraven/ddnss-forwarder
$ cd ddnss-forwarder
$ git submodule update --init
$ make build-docker
Then we start the docker container on the server using a port of your choice:
$ docker run -d --restart=always -p 1234:8080 ddnss-forwarder:0.0.1
In the configuration of the fritzbox you now use the following target URL for the DynDNS update:
http://<SERVER IP>:<PORT>/forward?key=<DDNSS KEY>&host=<HOST>&ip=<ipaddr>&ip6prefix=<ip6lanprefix>&ip6=<IPv6 SUFFIX>
Here, you have to replace the server ip, port, ddnss key, host and the ipv6 suffix with your actual values. An example of the URL looks like
http://192.168.100.2:1234/forward?key=secretkey&host=myhost.ddnss.org&&ip=<ipaddr>&ip6prefix=<ip6lanprefix>&ip6=a236:bcff:fee7:7b14