What are PTR (Pointer) Records?
Pointer records are used to map a network interface (IP) to a hostname for a Reverse DNS configuration. PTR records are configured within Reverse DNS domains (in-addr.arpa) domains.
Reverse DNS Overview
1. Select Managed DNS and click on Domains
2. Select the reverse DNS zone you want to add a PTR record too.3. Under the PTR Records section, click on the (+) icon to add a record.PTR Record Fields
A) Name — The last octet of the IP address you are configuring reverse DNS for.
B) TTL — The TTL (Time to Live) in seconds is the length of time the record will cache in resolving name servers and web browsers. The longer the TTL, then remote systems will lookup the DNS record less frequently. Your name servers will also receive less query traffic since most queries are answered by resolving name servers. Conversely, the shorter the TTL the faster any changes you make to your DNS will propagate in servers that have cached data. However, your domain will receive more query traffic.
Records that are static and don’t change often should have TTL’s set between 1800 (being on the low end) to 86400 seconds (30 minutes to 1 day cache).
Records configured with Failover or that change often should have TTL’s set anywhere from 180 to 600 (3 to 10 minutes cache).
If a change is needed for a record with a high TTL, then the TTL can be lowered prior to making the change and then raised back up again after the changes were made
C) System — This will be the host name of the computer or server the IP resolves too, for example mail.example.com. It is important to note, the domain name is automatically appended to the end of this field unless it ends with a dot (.).
D) Notes — Add a helpful note with keywords so you can search for your records later.
E) Save — Save your record changes and don’t forget to commit your changes after you’re done making record changes for this domain!