What is a PTR record and how to set them

PTR record is a piece of information based on which the DNS realises IP address ---> name translation. PTR records are not recorded in the same zone as the others (e.g. A or CNAME records) but in their own zone, the name of which starts with a seemingly strange word identifier (including something like addr arpa etc.) and ends with the reverse order of IP network octets. The problem with mail is the purpose PTR records are sometimes used for: if the client requires a service on the Internet, the inquiry is sent and the target server tries to perform a reverse translation based on the sender's IP -- if the PTR record and its zone exist and are "visible", the action results in translation to your domain name, thus confirming your existence. If the translation fails, some servers will deny their services.

In short, PTR record translates the IP address based on the domain name. This is crucial feature for e-mail services. The name can include any name, most often the name of a domain referring to the IP.

Reverse DNS record setup for IPv4 address

Enter https://cp.coolhousing.net/ website, where you log in the client section via your login name (email) and password.

Login into the Control Panel

After login you will see a quick overview of your service.

Overview of all your services in the CP

Click on the Clients profile and open the IPv4 Overview tab, or you can click on the IPv4 Addresses within the Dashboard, where you can see all your assigned IPv4 addresses.

IPv4 address detail

Detailed information about any IPv4 address including options to set reverse DNS record may be found under the IPv4 tab after you click on it.

IPv4 address network settings

In the IP Address detail click on the Set rDNS.

In the next tab you can set rDNS up

Enter the Reverse DNS with your specify rDNS and click on the Save tab. The DNS will be set up by your domain registrator.

More information how to set the DNS you can find in these sections:

We Set Domain DNS Records – Part 1

We Set Domain DNS Records – Part 2

We Set Domain DNS Records – Part 3

Save your rDNS setup

The settings will be active in 60 minutes...

Change will be active in 1 hour

Notice: some IPv4 addresses have to be changed manually only by datacenter support. Information about this implementation you can find directly in the section IPv4 rDNS.

Some changes have to be done by DC support

The request will be automatically created in the datacenter support as soon as you complete the form. You will be informed about implementation and the settings by an email.

An email will be sended to you about rDNS settings and change

Reverse DNS record setup for IPv6 address

A form for the IPv6 rDNS is not available right now, unfortunately. If you want to do so, please, contact the datacenter support via autorized email to This email address is being protected from spambots. You need JavaScript enabled to view it. or via autorized request in the client section (Helpdesk > Autorized request)..

If you want to set IPv6 up, please, contact helpdesk of our datacenter

Author: Jirka Dvořák