depois de seguir o manual em https://www.tombarbette.be/dynamic-dns-with-ovh/ temos que alterar o ficheiro /etc/default/ddclient de acordo com o seguinte:
# Configuration for ddclient scripts
# generated from debconf on dom ago 16 15:15:34 WEST 2020
#
# /etc/default/ddclient# Set to "true" if ddclient should be run every time DHCP client ('dhclient'
# from package isc-dhcp-client) updates the systems IP address.
run_dhclient="false"# Set to "true" if ddclient should be run every time a new ppp connection is
# established. This might be useful, if you are using dial-on-demand.
run_ipup="false"# Set to "true" if ddclient should run in daemon mode
# If this is changed to true, run_ipup and run_dhclient must be set to false.
run_daemon="true"# Set the time interval between the updates of the dynamic DNS name in seconds.
# This option only takes effect if the ddclient runs in daemon mode.
daemon_interval="300"
se a máquina não tiver um ip público temos que acrescentar o que se segue a seguir à linha protocol=dyndns2 no ficheiro /etc/ddclient.conf:
use=web, web=checkip.dyndns.com/, web-skip='Current IP Address: '
finalmente, reiniciar o serviço:
systemctl restart ddclient