Steps: Configure Namecheap Set-up DDCLIENT Test DDCLIENT Set up DDCLIENT to run at start-up Known Issue with DDCLIENT Configure Namecheap Follow the Namecheap guide here NOTE: For a subdomain "oxygen.copper.com", just replace @ with "oxygen" Set-up DDCLIENT #Install DDCLIENT on Fedora sudo dnf install ddclient #Edit the configuration file to update IP on your Dynamic DNS host sudo nano /etc/ddclient/ddclient.conf Press Ctrl+W and type the name of host for your Dynamic DNS. Mine is with Namecheap and I needed to configure for the subdomain hence following config reflects how to do it for Namecheap. For other hosts, you will need to refer their documentation. ## NameCheap (namecheap.com) ## use=web, web=dynamicdns.park-your-domain.com/getip protocol=namecheap, \ server=dynamicdns.park-your-domain.com, \ login=copper.com, \ password=<copy the password from namecheap advanced DN section> \ oxygen # myhost.namecheap.com The password to be provided above is what you will find on namecheap dashboard (Ref. Screenshot above). Log in to the namecheap account. Go to Advanced DNS Scroll down to Dynamic DNS section Copy the password Paste in ddclient config file Test DDCLIENT Before we schedule ddclient to run at boot, we need to test if it has been configured properly and is able to communicate with Namecheap by sudo ddclient -daemon=0 -debug -verbose -noquiet. If it is configured properly, you will see a message similar to this as part of the final output. SUCCESS: updating oxygen: good: IP address set to 92.117.273.56 If it is not what you see, and more importantly, if you do not see last line as "Success", then there is something wrong with configuration and you must correct it before proceeding. If this test worked, we are ready to update the DDCLIENT service. Set up DDCLIENT to run at start-up When we install ddclient using dnf, a ddclient.service file is automatically created in the location /etc/systemd/system/ddclient.service with following content. [Unit] Description=A Perl Client Used To Update Dynamic DNS After=syslog.target network.target nss-lookup.target [Service] User=ddclient Group=ddclient Type=forking PIDFile=/var/run/ddclient/ddclient.pid EnvironmentFile=-/etc/sysconfig/ddclient ExecStartPre=/bin/touch /var/cache/ddclient/ddclient.cache ExecStart=/usr/sbin/ddclient $DDCLIENT_OPTIONS [Install] WantedBy=multi-user.target We will enable and start this service by issuing following commands: sudo systemctl enable ddclient.service sudo systemctl start ddclient.service One would think that enabling and starting this service is all you need to do but that is not usually the case. I was getting following error: /bin/touch: cannot touch `/var/cache/ddclient/ddclient.cache': Permission denied A quick google search establishes that there seems to be some bug in how the ddclient cache file is created and how the permissions are set. After lot of searching, scratching head later, I did the following which fixed the issue. So if sudo systemctl start ddclient results in error, you may need to do the following: #Go Root su #Create a directory for ddclient mkdir /var/run/ddclient #Chown the various directories for ddclient as user chown ddclient:ddclient /etc/ddclient.conf chown ddclient:ddclient /var/run/ddclient/ #change directory cd /var/run/ddclient #delete ddclient.cache if it exists rm ddclient.cache #change directory cd /etc/sysconfig #delete ddclients.cache rm ddclients.cache #create a blank ddclient.cache nano /var/run/ddclient/ddclient.cache #chown it for ddclient user chown ddclient:ddclient /var/run/ddclient/ddclient.cache #exit root exit #enable and start ddclient service sudo systemctl enable ddclient.service sudo systemctl start ddclient.service Done !!! Known Issue with DDCLIENT There is a known issue and I can confirm that I have seen on my logfile as recently as today. WARNING: cannot connect to dynamicdns.park-your-domain.com:80 socket: IO::Socket::INET: Bad hostname 'dynamicdns.park-your-domain.com' It isn't major but it is there and restarting the service by issuing the command sudo systemctl restart ddclient.service fixes the problem.