dns ptr

Overview

From Wikipedia https://en.wikipedia.org/wiki/Reverse_DNS_lookup

A reverse DNS lookup or reverse DNS resolution (rDNS) is the querying technique of the Domain Name System (DNS) to determine the domain name associated with an IP address – the reverse of the usual "forward" DNS lookup of an IP address from a domain name.

DNS configuration

Create a PTR record that point your IP address to your domain name. Important Some providers require PTR configuration to be done from their dashboard and ignore DNS records. Please, make sure to properly configure reverse DNS lookup for your domain.

To verify, the following command:

dig @1.1.1.1 -x $( ip addr show eth0 | grep 'inet ' | awk '{print $2}' | cut -d'/' -f1)

should return your domain name.