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

[Matthijs Mekking]

Hi Oli,

I must admit when implementing it I didn't consider to find a CNAME RRset.

I'll add another ticket to cover this issue.

Best regards,

Matthijs

On 9/17/26 11:43, Oli Schacher via bind-users wrote:
> 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
>