Questions about RFC 9859 generalized NOTIFY(CDS) support in BIND

[Oli Schacher]

Hi Matthijs

On 15.09.2026 17:09, Matthijs Mekking via bind-users wrote:

> Thank your for your interest in Generalized DNS Notifications.

Thank you for implementing it!
> 
> You are right that these points are not implemented in BIND 9 currently.
> 
> I actually have made work items for the four feature requests. See below. We will work on them on a best effort basis. 
Excellent, thanks. I do realize that this feature is probably not on top 
of the priority list ;-)

In my tests, I noticed another potential issue: We have published a 
generalized notify endpoint via a CNAME:

einbeispiel._dsync.ch.	CNAME	ch-dsync.switch.ch.
ch-dsync.switch.ch.	DSYNC	CDS NOTIFY 5359 nudge.switch.ch.

But apparently, BIND does not like that:

"zone einbeispiel.ch/IN (signed): Unable to fetch 
einbeispiel._dsync.ch/DSYNC: cname"

I'm assuming that means "I asked for DSYNC but got CNAME instead and do 
not accept that".

Is it intentional behavior to not chase CNAME for this lookup, i.e. is 
the parent required to return a DSYNC RRSET directly or is this also 
something that could be changed in the BIND implementation?

Cheers

Oli