How do I configure an IPv6 PTR record?
PTR records are usually set with your hosting provider. They are not part of your domain’s zone file.
This means that you’ll always set reverse DNS for your Linodes in the Linode Manager, even if your nameservers are elsewhere.
You can follow Linode's guide on rDNS here:
Likewise, if you have servers somewhere else but are using Linode’s nameservers, you will still have to set up your PTR records with your hosting provider.
As a prerequisite for adding a PTR record, you need to create a valid, live 'A' or 'AAAA' record that points the desired domain to that IP.
For IPv6, you will need to configure an 'AAAA' record.
In the DNS Manager tab in your Linode Manager, you will want to click the 'Add a new A/AAAA record'.
A typical 'AAAA' record looks like the following:
example.com AAAA 0123:4567:89ab:cdef:0123:4567:89ab:cdef
Once the 'AAAA' is created, configuring an IPv6 PTR record is a simple as pointing the domain to your Linode’s IPv6 address.