1. DNS/1/RCODE/NXDomain

SOA record in NXDOMAIN response means where are NO zone cuts!

• Under the name of the label of SOA record, NO zone cuts exist.

/example.jp /www.nsd.e-ontp.com

NXDOMAIN返答であっても、SOAレコードがあるとは限らない。

• どういう場合か。(クイズ)

NXDOMAIN返答であっても、Answer Sectionがあることがある。/例

https://twitter.com/tss_ontap_o/status/907832980374159361

DNS 温泉 4 の予習して悩んでいる人がもっと悩めるスレ > 

"CNAME and NXDOMAIN" https://www.ietf.org/mail-archive/web/namedroppers/current/thrd8.html#06284

• …

14:07 - 2017年9月13日

2. response format

RCODE=NXDomain, AA=1

• No Answer Section
• Authority Section contains a SOA record (owner is at/below cut and at/above query name)
• No Additionl Section

https://www.ietf.org/proceedings/94/slides/slides-94-dnsop-9.pdf

https://tools.ietf.org/html/draft-ietf-dnsop-nxdomain-cut-01

NXDOMAIN really means there is nothing underneath

• draft-ietf-dnsop-nxdomain-cut-01

This document states clearly that when a DNS resolver receives a

• response with response code of NXDOMAIN, it means that the domain name which is thus denied AND ALL THE NAMES UNDER IT do not exist.

REMOVE BEFORE PUBLICATION: this document should be discussed in the

• IETF DNSOP (DNS Operations) group, through its mailing list. The source of the document, as well as a list of open issues, is currently kept at Github [1].

This documents clarifies RFC 1034 and modifies a bit RFC 2308 so it

• updates both of them.