Dear Richard Gibson,
Thanks a lot for your kind review and questions.
some comments are below inline.
Jiankang Yao
From: Richard Gibson
Date: 2017-09-19 10:48
To: dnsop
Subject: Re: [DNSOP] I-D Action: draft-yao-dnsop-accompanying-questions-04.txt
I have some questions about this draft.
How should responders populate the COUNT fields when one record answers
multiple accompanying questions? For example, assume example.com has an MX
record but no A or AAAA (the latter two thus being covered by an authority
section SOA):
QUESTION example.com. IN MX
AQ example.com. IN A
AQ example.com. IN AAAA
ANSWER example.com. 3600 IN MX 10 mail.example.net.
AUTHORITY example.com. 3600 IN SOA …
example.com. 3600 IN SOA …
ADDITIONAL . 0 CLASS4096 OPT ???
In a more general sense, how are responders to generate—and how are initiators
to interpret—responses in which it is not clear which question any given
response record corresponds to?
[Jiankang Yao]
The responders will put the query result of main question first, then
Accompanying Question 1, Accompanying Question 2 in the answer, authority or
additional section. It means that the responders will put the results for main
question first, then Accompanying Question 1, Accompanying Question 2, one by
one in order.
The initiators will also interpret the result in the answer, authority or
additional section, one question by one question in order, main question first,
then Accompanying Question 1, Accompanying Question 2. The interpretation will
base on the value of
ANCOUNT, ARCOUNT, NSCOUNT, and AQ-ANCOUNT, AQ-ARCOUNT, AQ-NSCOUNT.
In your example above,
ANCOUNT=1, ARCOUNT=1, NSCOUNT=0;
AQ1-ANCOUNT=0, AQ1-ARCOUNT=0, AQ1-NSCOUNT=1;
AQ2-ANCOUNT=0, AQ2-ARCOUNT=0, AQ1-NSCOUNT=1
so the initiators will know:
the result for main question is:
ANSWER example.com. 3600 IN MX 10 mail.example.net.
AUTHORITY
ADDITIONAL . 0 CLASS4096 OPT ???
the result for accompanying question 1 is:
ANSWER
AUTHORITY example.com. 3600 IN SOA …
ADDITIONAL
the result for accompanying question 2 is:
ANSWER
AUTHORITY example.com. 3600 IN SOA …
ADDITIONAL
Section 3 defines the prefix field of an accompanying question as "a domain
name with the form of a dot or a sequence of labels ending with a pointer"...
could you clarify that "the form of a dot" refers to the root domain name
(i.e., a single null label with wire format 0x00)?
[Jiankang Yao]
sorry for confusion words. it means a single null label .
In section 4, what is meant by "the responder assembles the prefix with the
main domain name"? Wire-format domain names are necessarily fully-qualified,
whether or not they end with compression pointers. Is the operation to be
interpreted as something like "if the prefix is the DNS root domain, treat it
as the QNAME"? If so, I think such special processing is unnecessary, because
it's already possible to reference the QNAME directly with a compression
pointer.
[Jiankang Yao]
thanks, You are right. I will clarify the words.
Why require accompanying question names to match or be subdomains of the QNAME?
It precludes potentially useful queries like QNAME=www.example.com. accompanied
by prefix=static.example.com., and prohibiting them doesn't prevent
out-of-bailiwick queries anyway.
[Jiankang Yao]
currently the use cases for accompanying questions are the same domain names
with different typs (A and AAA) or different sub domain names (TLSA record:
_443._tcp.www.example.com ).
If we can find some strong use cases for queries like QNAME=www.example.com.
accompanied by prefix=static.example.com, we may consider to adjust the design.
Section 5 references a "not been implemented, too many accompanying-questions."
response... what would that response look like?
[Jiankang Yao]
Here, I think that it need a new rcode value for it.
Best Regards.
Jiankang Yao
On Sun, Sep 17, 2017 at 11:19 PM, <internet-dra...@ietf.org> wrote:
A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Domain Name System Operations WG of the IETF.
Title : A DNS Query including A Main Question with
Accompanying Questions
Authors : Jiankang Yao
Paul Vixie
Ning Kong
Xiaodong Li
Filename : draft-yao-dnsop-accompanying-questions-04.txt
Pages : 11
Date : 2017-09-17
Abstract:
This document enables DNS initiators to send a main question
accompanying with several related questions in a single DNS query,
and enables DNS responders to put the answers into a single DNS
response. This extension enables a range of initiators to look up
"X, or failing that, Y" in a better way than both current
alternatives. This mechanism can reduce the number of DNS round-
trips per application work-unit.
The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-yao-dnsop-accompanying-questions/
There are also htmlized versions available at:
https://tools.ietf.org/html/draft-yao-dnsop-accompanying-questions-04
https://datatracker.ietf.org/doc/html/draft-yao-dnsop-accompanying-questions-04
A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-yao-dnsop-accompanying-questions-04
Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.
Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/
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