Linux Domain Name Configuration. In case you havent. Configure domain name in Ubuntu Edit your hostname not FQDN in etchostname file.
Set or change FQDN domain name on Ubuntu 2004 Focal Fossa Linux You can set or change the system FQDN using network interface config file too. Host is a simple utility for performing DNS lookups. For example you may want to test a website locally with a custom domain name before going live publicly by modifying the etchosts file on your local system to point the domain name to the IP address of the local DNS server you configured.
The size limit of 64 characters is enforced.
Check them for install if not found install them. Static and transient host names to consist of a-z A-Z 0-9 - _ and. Add domain in. Only to not begin or end in a dot and to not have two dots immediately following each other.