Hello there,
It has been a while since I posted.
I decided to do DDNS on my home network using Bind9 and the ISC DHCP server.
As always you test on a lab first.
I have EVE-NG and I was running a lab with DDNS and IPV6.
I used Fedora core so to make it like my network I replaced the server with Ubuntu 20.04.
However, I run into an interesting problem.
DDNS worked fine if I used IPV4 or IPV6 but not both bummer!
However, it pays to read the documentation does it not?
Refer to https://www.isc.org/blogs/using-dual-stack-mixed-mode-dsmm-with-ddns-in-isc-dhcp-4-4/
To make a long story short on dual-stack clients, clients are trying to write their hostnames to DNS and want them to be the same.
Thus, a client will want its hostname written as an A and as an AAAA record.
This is an issue with the ISC DHCP server because it runs separate daemons for IPV4 and IPV6.
You can read it above but basically, you cannot configure both instances to either use the standard or interim mode.
This is a bug on version 4.3 and below.
They do not generate the same client IDs and thus one of the mechanisms fails.
Version 4.4 fixes this.
You need to enable update-conflict-detection and dns-dual-stack-mixed-mode then you need to make one server use the standard scheme and the other the interim scheme.
Whichever you prefer and voila now my test setup correctly adds A and AAAA records dynamically.
I spent a Saturday evening trying to fix the issue which if I had read the documentation would have taken me 10 minutes to solve.
Oh well, now I need to implement this on my home network.
Ciao.