how to create ptr record

In a reverse-mapping zone, a PTR (pointer) record maps an IP address to a hostname. Before adding a PTR record to a reverse-mapping zone, you must first create the zone. You can also add PTR records to forward-mapping zones to support zeroconf (zero configuration networking), such as wide-area Bonjour. For information about the Bonjour protocol, refer to  http://www.apple.com/support/bonjour. Though adding PTR records to forward-mapping zones supports some of the use cases in RFC 1101, it does not support the network name mapping use case described in the RFC. For more information, refer to  http://tools.ietf.org/html/rfc1101.

To create a PTR Record, complete the following:

1. From the Cloud Services Portal, click Manage -> DNS -> Zones.
2. Click the DNS view.
3. Click the zone.
4. Click Create -> Record and select PTR Record from the drop-down list.
5. On the Create PTR Record page, select or specify the following:
   
6. Click Save & Close to save.