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Automatic rDNS (Auto-PTR)

Xenyth Cloud simplifies reverse DNS (rDNS) management with our Auto-PTR feature. This allows you to automatically generate Pointer (PTR) records for all IPs within a given range using a simple templating format. This is particularly useful for dynamically assigning PTR records to your VMs, dedicated servers, or other services.

What is Reverse DNS?​

Reverse DNS resolves an IP address to a hostname, which is the opposite of a typical (forward) DNS lookup that resolves a hostname to an IP. PTR records are used for this. Many online services, especially email servers, perform rDNS checks as a security measure to validate the source of a connection.

How Auto-PTR Works​

Our system allows you to define a wildcard record within a reverse DNS zone. This record serves as a template to dynamically generate PTR records for any IP address within that zone.

Step 1: Create an rDNS Zone​

First, you need to create a reverse DNS zone for your IP range in the Xenyth Cloud dashboard.

  1. Navigate to the DNS section of the dashboard.
  2. Create a Basic or better DNS service, with the appropriate ARPA zone, check your RIR or LIR to see what your ARPA zones should be.

Step 2: Create a Wildcard PTR Record​

Once the zone is created, you can add a wildcard record to it.

  1. In your new rDNS zone, click Add Record.
  2. For the record name/host, enter a wildcard *.
  3. In the content/value field, enter your desired template. The system will replace a placeholder with the IP address being looked up.

IPv4 Templating​

For IPv4 addresses, the placeholder %5% represents the full IP address, with each dot (.) replaced by a hyphen (-).

  • Template: %5%.static.as835.net
  • IP Address: 192.168.1.1
  • Resulting PTR Record: 192-168-1-1.static.as835.net

IPv6 Templating​

For IPv6 addresses, the placeholder %33% represents the compressed IPv6 address. Colons (:) are replaced with hyphens (-).

  • Template: %33%.static6.as835.net
  • IP Address: 2001:a::1
  • Resulting PTR Record: 2001-a--1.static6.as835.net