To reproduce
set service dns dynamic interface eth2 service dynv6 host-name 'xxx' set service dns dynamic interface eth2 service dynv6 login 'none' set service dns dynamic interface eth2 service dynv6 password 'p@sssw' set service dns dynamic interface eth2 service dynv6 protocol 'dyndns2' set service dns dynamic interface eth2 service dynv6 server 'dynv6.com'
Logs:
Oct 08 17:15:23 r1-roll ddclient[19079]: WARNING: malformed IPv4 address (fe80::5054:ff:fe31:79b2) Oct 08 17:16:23 r1-roll ddclient[19324]: WARNING: malformed IPv4 address (fe80::5054:ff:fe31:79b2) Oct 08 17:17:23 r1-roll ddclient[19511]: WARNING: malformed IPv4 address (fe80::5054:ff:fe31:79b2) Oct 08 17:18:23 r1-roll ddclient[19694]: WARNING: malformed IPv4 address (fe80::5054:ff:fe31:79b2) Oct 08 17:19:23 r1-roll ddclient[19877]: WARNING: malformed IPv4 address (fe80::5054:ff:fe31:79b2) Oct 08 17:20:23 r1-roll ddclient[20063]: WARNING: malformed IPv4 address (fe80::5054:ff:fe31:79b2)
The reason is option use of ddclient.conf https://github.com/vyos/vyos-1x/blob/adc7ef387d40e92bd7163ee6b401e99e554394a3/data/templates/dynamic-dns/ddclient.conf.tmpl#L12
# ddclient configuration for interface "eth2" use=if, if=eth2
For ipv6 should be option usev6 https://desec.readthedocs.io/en/latest/dyndns/configure.html#manual-configuration-other-systems
usev6=if, if=eth2
After changing option:
Oct 08 17:30:42 r1-roll ddclient[22035]: SUCCESS: updating xxx.dynv6.net: good: IP address set to xxxx:xxxx:71:458::126