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

[Doug Barton]

On 03/18/2017 09:20 AM, Anand Buddhdev wrote:
> 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,

You mean, perhaps, something like the DNS?

How do you propose to reliably delete the NS records in the first place 
if you don't know what they are?

Doug