On Feb 27, 2013, at 21:50, Roy Arends wrote:

> When a parent and child zone are served from the same server set, like co.uk 
> and uk, you could have _in_theory_ DS records without NS records in the 
> parent zone. A resolver would never observe the delegation point NS record. A 
> validating resolver would need to explicitly ask for the DS record. If the DS 
> record is present, the DS plus signatures will be returned. However, absence 
> of the DS record is problematic, as there is no NSEC(3) record indicating 
> presence of NS, absence of SOA+DS. 

Roy, that idea bothers me.

It's true, if all of the name servers for the parent are all of the name 
servers for a child, the NS set is not necessary.  But claiming then you could 
have DS records means the same name would have to own DNSKEY records (for the 
DS to reference) and then an SOA to allow the owner to appear in the RRSIG's 
signer name field.  Sure you don't need the NS, but you need everything else 
that makes a zone cut.  But wait, there's more.  The NSEC/NSEC3 record really 
ought to indicate that there's a delegation there and for that the NS bit has 
to be turned on - so there's a need for an NS.

> I think you'd need to implement these specifics though, as current 
> authoritative servers and signers might throw an error when observing a DS 
> without NS, but I haven't checked.

Without specifically saying what error would be thrown (and when, on zone 
load?), current servers should have issues with a name owning a DS and no NS.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Edward Lewis             
NeuStar                    You can leave a voice message at +1-571-434-5468

There are no answers - just tradeoffs, decisions, and responses.

_______________________________________________
DNSOP mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/dnsop

Reply via email to