What are PTR Records?
A pointer record, or PTR record, is a type of Domain Name System (DNS) record used for reverse DNS lookup.
Reverse DNS lookups allow you to find the domain name, or hostname, for any specified IP address – the opposite of a regular DNS lookup.
Note: An A record should exist for every PTR record.
Here’s an example of a PTR record with the domain being hostname.example.com, and the IP address is 192.168.0.1.
Note how the Host field looks like the IP address in reverse, followed by ” in-addr.arpa”. This is the form that PTR records follow.
A PTR record is used to provide the domain name associated with the IP address. A DNS PTR record is the opposite of the ‘A’ record. A record provides the IP address associated with the domain name
DNS PTR is used in reverse DNS lookups and whenever the user enters the domain name, DNS PTR acts as the query that start with the IP address and look up the domain name
Commom Uses of DNS PTR records –
- Anti -Spam – Email providers use this technology to track the reverse DNS to check the domain names of email addresses and validate the IP address associated are legitimate or not
- Log Tracking – System logs usually tracks IP addresses. DNS PTR reverse DNS lookup and can convert into human readable domain names for better tracking
- Troubleshoot Email Delivery Issues – DNS PTR can help to troubleshoot email delivery issues as anti-spam filters have the check for missing PTR records. So, if the domain has no PTR record or PTR record contains wrong domains, email service can block emails from that domain