Tks for your advice.
$ dpkg -l | grep ddclient
ii ddclient 3.6.2-6ubuntu1 Update dynamic IP address at DynDNS.org
ddclient is running.
IP address was updated on DYNDNS.ORG server whenever this server reconnected. I have it confirmed on login DYNDNS.ORG website.
But failed to ping my domain.
$ sudo ping -c 3 satimis.homelinux.com
PING satimis.homelinux.com (18.104.22.168) 56(84) bytes of data.
--- satimis.homelinux.com ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2001ms
iptables has been stopped.
Please advise how fix this problem.