ddclient
ddclient updates dynamic DNS entries for accounts
...It runs as a daemon or from cron, with configurable intervals, SSL/TLS for provider communication, and robust logging to aid troubleshooting. A single configuration file defines multiple hosts, credentials, and per-record options, making complex setups straightforward. In practice, ddclient turns dynamic residential or small-office internet links into stable hostnames for VPNs, home labs, and self-hosted services.