IP addresses > Configuring Reverse DNS for a public IP address

08 Configuring Reverse DNS for a public IP address

What Reverse DNS is and what it is used for

This guide explains how to configure Reverse DNS for public IP addresses used with OpenStack Cloud Server and VMware Cloud Server.

Reverse DNS allows you to look up the hostname (FQDN, Fully Qualified Domain Name) associated with a public IP address using a PTR DNS record. This configuration is particularly useful for email servers, as it can help verify the identity of the sending server and improve the reliability of email communications.

Adding a hostname to Reverse DNS

Reverse DNS configuration is not available for public IP addresses associated with Cloud VPS instances.

You can configure Reverse DNS for a public IP address whether its status is ACTIVE or INACTIVE.

To add a hostname to the Reverse DNS configuration of a public IP address:

  • access the details page of the public IP address;
  • select the Edit (Manage Reverse) tab;
  • in the Reverse DNS section, select Add hostname;
  • in the Hostname 1 field, enter the fully qualified domain name (FQDN);
    • to add more hostnames, select Add hostname again and complete the corresponding fields;
  • select SAVE CHANGES;
  • in the Confirmation window, select CONFIRM CHANGES.
Reverse DNS changes are applied immediately, but DNS propagation may take up to 48 hours.

Modifying or deleting a hostname from Reverse DNS

To modify or delete a hostname associated with Reverse DNS:
  • access the details page of the public IP address;
  • select the Edit (Manage Reverse) tab;
  • in the Reverse DNS section:
    • to modify a hostname, update the domain name in the corresponding field;
    • to delete a hostname, select the corresponding DELETE button.
  • select SAVE CHANGES;
  • in the Confirmation window, select CONFIRM CHANGES.
Reverse DNS changes are applied immediately, but DNS propagation may take up to 48 hours.