ddclient: do not update IPv4, but just IPv6 [closed]
Solution 1:
Assuming a sufficiently new Perl ddclient perhaps
use=if
ipv6=yes
ipv4=no
Makes use of the OS interface command to find IPs, ip on Linux, others on other platforms.
My reading of the source is that it only does one address family, I think. Disabled v4 just in case. Per the template config file, IPv6 requires newer than 3.8.1.
Or, consider using a v6 only network for some hosts. Remove all (non-loopback) v4 addresses from interfaces. Implement transition methods like DNS64/NAT64 where required to connect to IPv4 hosts.