The PTR record type
The PTR (pointer) record type holds a pointer to a canonical name. This is most often used for reverse DNS lookups.
Here, we query for PTR records of the domain “
This unusual-looking domain name represents a reverse DNS lookup: instead of finding the IP for a domain name, we are asking for the hostname of an IP — in this case, the IP address “
As expected, the DNS server responds with "
$ dog PTR 22.214.171.124.in-addr.arpa PTR 126.96.36.199.in-addr.arpa. 0s "localhost."