This article explains how to enable automatic PTR record creation in UltraDNS.
Use this article when you want UltraDNS to automatically create matching PTR records for supported standard IPv4 reverse DNS zones.
Before You Begin
- Automatic PTR record creation applies only to standard
/24,/16, and/8reverse DNS zones. - Classless reverse DNS zones are not supported for automatic PTR record creation.
- The applicable reverse DNS zone must exist in UltraDNS.
- The applicable reverse DNS zone must be delegated to UltraDNS name servers for the PTR record to resolve publicly.
- This setting does not delegate reverse DNS to UltraDNS and does not make UltraDNS authoritative for an IP block by itself.
How Automatic PTR Creation Works
Reverse DNS for IPv4 uses the in-addr.arpa namespace.
For IPv4 address a.b.c.d, the full PTR owner name is d.c.b.a.in-addr.arpa.
In a standard /24 reverse DNS zone, the reverse DNS zone is usually c.b.a.in-addr.arpa, and the PTR record name inside that zone is d.
UltraDNS can create the matching PTR record only when the related supported reverse DNS zone is available in UltraDNS.
Example
A record:
mail.example.com A 1.2.3.4
Standard /24 reverse DNS zone:
3.2.1.in-addr.arpa
PTR record name inside that reverse DNS zone:
4
Full PTR owner name:
4.3.2.1.in-addr.arpa
PTR target:
mail.example.com.
Enable Automatic PTR Record Creation
- Log in to the UltraDNS Portal.
- Click My Profile in the upper-right corner of the portal.
- Click General Preferences.
- Locate Automatically create PTR records.
- Select Enabled.
- Click Save.
Expected Outcome
After the setting is enabled, UltraDNS can automatically create the matching PTR record when a supported A record is created and the applicable supported reverse DNS zone exists in UltraDNS.
If the applicable reverse DNS zone does not exist in UltraDNS, is not delegated to UltraDNS name servers, or is a classless reverse DNS zone, the PTR record must be created or managed manually.
Important Notes
- PTR records must be created in the applicable reverse DNS zone, not in the forward DNS zone.
- Hosting a forward DNS zone in UltraDNS does not automatically mean UltraDNS hosts reverse DNS for the related IP address.
- Do not confuse the full PTR owner name with the reverse DNS zone name.
- For IP address
1.2.3.4, the full PTR owner name is4.3.2.1.in-addr.arpa, but the standard/24reverse DNS zone is3.2.1.in-addr.arpa. - For classless reverse DNS delegation, create and manage PTR records manually in the delegated classless reverse DNS zone.