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What is PTR Record?

PTR records are used for the reverse DNS (Domain Name System) lookup. Using the IP address you can get the associated domain/hostname. An A record should exist for every PTR record. The usage of a reverse DNS setup for a mail server is a good solution.

While in the domain DNS zone the hostname is pointed to an IP address, using the reverse zone allows to point an IP address to a hostname.
In the Reverse DNS zone, you need to use a PTR Record. The PTR Record resolves the IP address to a domain/hostname.

How to create PTR record?

In order to create a PTR record, at first need to be created a Reverse DNS zone. The reverse DNS zone depends on the size of your IP network. In our example we will use an IPv4 /24 network. In the /24 network, you have 255 unique IP addresses. For an example, if our network is 192.168.0.0/24, the available IPs in this network are from 192.168.0.1 to 192.168.0.255 and our reverse zone has following format: 0.168.192.in-addr.arpa

In order to create a reverse DNS zone go to the Control Panel, click on the Add new zone button and choose Master Reverse DNS zone and fill the reverse zone name of your IP network. In our case this is 0.168.192.in-addr.arpa

Now in our reverse zone 0.168.192.in-addr.arpa we can add PTR records for each IP from the network. From the button "Add new record" we can add new PTR record and here are few examples for the first two IP address:

For 192.168.0.1:

Type: PTR
Host: 1
Points to: hostname1.example.com

For 192.168.0.2:

Type: PTR
Host: 2
Points to: hostname2.example.com

The PTR records has the following look in the Control Panel:

Host: Type: Points to: TTL
1.0.168.192.in-addr.arpa PTR hostname1.example.com 1 Hour
2.0.168.192.in-addr.arpa PTR hostname2.example.com 1 Hour

After creating the PTR record, you need to change the name servers of your reverse zone at your IP provider or ask him to assiist you with the change.

We are supporting Reverse DNS zones both for IPv4 and IPv6 networks. Just write to our technical support, if you need assistance with the configuration of the Reverse DNS and PTR records of your network.

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