Re: [core] Dnsdir early review of draft-ietf-core-dns-over-coap-01

Martine Sophie Lenders <m.lenders@fu-berlin.de> Tue, 17 January 2023 15:23 UTC

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Date: Tue, 17 Jan 2023 16:23:29 +0100
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To: Tim Wicinski <tjw.ietf@gmail.com>, dnsdir@ietf.org
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From: Martine Sophie Lenders <m.lenders@fu-berlin.de>
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Subject: Re: [core] Dnsdir early review of draft-ietf-core-dns-over-coap-01
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Hi Tim,

many thanks your review, we highly appreciate it! And sorry for the late
reply. The transition to the new year was very packed.

On 22.12.22 18:12, Tim Wicinski via Datatracker wrote:
> Reviewer: Tim Wicinski
> Review result: On the Right Track
> 
> 
> 
> I'm doing an early review of draft-ietf-core-dns-over-coap
> for the DNS Directorate.  This is only an early review.
> 
> Status:  On the right track, but should have another review or reviews
> as it reaches WGLC status.
> 
> While this draft is focused on the communication between a DNS-over-CoAP client
> and DNS-over-CoAP server, the communication between the DNS-over-CoAP Server
> and the "DNS Server" is done using DNS-over-DTLS, which the DNS community has
> not seen implementations in use.  The whole communication between the
> the DoC Server and the "DNS Server" should be expanded upon.

In the draft, we tried to articulate that the DoC Server is just a DNS 
client (either a recursive resolver or stub resolver). The communication 
between the DoC Server and the existing DNS infrastructure (any 
recursive or authoritative DNS server) is based on common DNS protocols. 
This might be DNS-over-DTLS, but could also be classic DNS-over-UDP.

Would the following figure help?

+------------+        +------------+       +------------+
|            |        |            |       | DNS Infra- |
| DoC Client |--CoAP--| DoC Server |--DNS--| structure  |
|            |        |            |   |   |            |
+------------+        +------------+   |   +------------+
                                        |
                                        \ DNS over UDP|DTLS|...


> The document talks about "DNS Server" but it needs to be more precise - is this
> a DNS Recursive Resolver, Stub Resolver or DNS Authorative Server?  The document
> needs to be more precise about this.  Please see
> https://www.rfc-editor.org/rfc/rfc8499#page-16 for more details.

Thanks! We will clarify in the next version.

> Before WGLC, from the DNS perspective a working implementation for observation.
> While the authors and WG may feel that this DNS interaction will be
> constrained to the CoAP environment, but those who operate DNS
> infrastructure will feel this may be wishful thinking.

We provide two reference implementations, one DoC client implementation
available in the IoT operating system RIOT [1], and one DoC server
implementation in Python [2].

Best
Martine


[1] https://doc.riot-os.org/group__net__gcoap__dns.html
[2] https://github.com/miri64/aiodnsprox/

[core] Dnsdir early review of draft-ietf-core-dns… Tim Wicinski via Datatracker
Re: [core] Dnsdir early review of draft-ietf-core… Martine Sophie Lenders
Re: [core] Dnsdir early review of draft-ietf-core… Tim Wicinski
Re: [core] Dnsdir early review of draft-ietf-core… Martine Sophie Lenders
Re: [core] Dnsdir early review of draft-ietf-core… Martine Sophie Lenders