[dns-operations] Cleaning up glue with dynamic DNS updates

[Anand Buddhdev]

Hello DNS experts,

If I am using dynamic DNS updates with a zone, how do I handle cleaning
up glue records? For example, suppose I update a zone with the following
(using nsupdate):

zone example.com.
update add a.ns.sub.example.com. A 192.0.2.1
update add b.ns.sub.example.com. A 192.0.2.2
update add sub.example.com. NS a.ns.sub.example.com.
update add sub.example.com. NS b.ns.sub.example.com.
send

At some later time, if I want to change or delete the delegation to
sub.example.com, how can I ensure that the associated glue records are
also removed? I don't think nsupdate allows this.

Oh, I have considered the setup where I have to remember what I added,
in some persistent storage, so I can look it up later and remove it.
However, if I don't have such a record in persistent storage, is there
any way to reliably delete the glue as well?

Regards,
Anand