I've turned on "Dynamic DNS" in System Settings / Services. The configuration appears in /etc/inadyn.conf as expected, but the address doesn't get updates. In /var/log/syslog:
Mar 9 09:58:19 home systemd: inadyn.service: Succeeded.
Mar 9 10:00:19 home inadyn: inadyn: Not starting. Disabled in /etc/default/inadyn.
Looks like the service is indeed turned off in /etc/default/inadyn:
- Please note, /etc/inadyn.conf should be properly configured before running inadyn
- Set to "yes" if inadyn should run in daemon mode
- If this is changed to "yes", RUN_IPUP must be set to "no".
- Set to "yes" if inadyn should be run every time a new ppp connection is
- established. This might be useful, if you are using dial-on-demand.
- The user and group that inadyn should be run as.