draft-ietf-dnsop-dns-terminology-03.txt   draft-ietf-dnsop-dns-terminology-04.txt 
Network Working Group P. Hoffman Network Working Group P. Hoffman
Internet-Draft VPN Consortium Internet-Draft ICANN
Intended status: Best Current Practice A. Sullivan Intended status: Informational A. Sullivan
Expires: December 24, 2015 Dyn Expires: March 3, 2016 Dyn
K. Fujiwara K. Fujiwara
JPRS JPRS
June 22, 2015 August 31, 2015
DNS Terminology DNS Terminology
draft-ietf-dnsop-dns-terminology-03 draft-ietf-dnsop-dns-terminology-04
Abstract Abstract
The DNS is defined in literally dozens of different RFCs. The The DNS is defined in literally dozens of different RFCs. The
terminology used in by implementers and developers of DNS protocols, terminology used by implementers and developers of DNS protocols, and
and by operators of DNS systems, has sometimes changed in the decades by operators of DNS systems, has sometimes changed in the decades
since the DNS was first defined. This document gives current since the DNS was first defined. This document gives current
definitions for many of the terms used in the DNS in a single definitions for many of the terms used in the DNS in a single
document. document.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 24, 2015. This Internet-Draft will expire on March 3, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. DNS Header and Response Codes . . . . . . . . . . . . . . . . 5 3. DNS Header and Response Codes . . . . . . . . . . . . . . . . 6
4. Resource Records . . . . . . . . . . . . . . . . . . . . . . 6 4. Resource Records . . . . . . . . . . . . . . . . . . . . . . 7
5. DNS Servers . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. DNS Servers and Clients . . . . . . . . . . . . . . . . . . . 8
6. Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 6. Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7. Registration Model . . . . . . . . . . . . . . . . . . . . . 15 7. Registration Model . . . . . . . . . . . . . . . . . . . . . 16
8. General DNSSEC . . . . . . . . . . . . . . . . . . . . . . . 16 8. General DNSSEC . . . . . . . . . . . . . . . . . . . . . . . 17
9. DNSSEC States . . . . . . . . . . . . . . . . . . . . . . . . 18 9. DNSSEC States . . . . . . . . . . . . . . . . . . . . . . . . 20
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
11. Security Considerations . . . . . . . . . . . . . . . . . . . 20 11. Security Considerations . . . . . . . . . . . . . . . . . . . 21
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 21 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 22
13.1. Normative References . . . . . . . . . . . . . . . . . . 21 13.1. Normative References . . . . . . . . . . . . . . . . . . 22
13.2. Informative References . . . . . . . . . . . . . . . . . 22 13.2. Informative References . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction 1. Introduction
The domain name system (DNS) is a simple query-response protocol The domain name system (DNS) is a simple query-response protocol
whose messages in both directions have the same format. The protocol whose messages in both directions have the same format. The protocol
and message format are defined in [RFC1034] and [RFC1035]. These and message format are defined in [RFC1034] and [RFC1035]. These
RFCs defined some terms, but later documents defined others. Some of RFCs defined some terms, but later documents defined others. Some of
the terms from RFCs 1034 and 1035 now have somewhat different the terms from RFCs 1034 and 1035 now have somewhat different
meanings than they did in 1987. meanings than they did in 1987.
This document collects a wide variety of DNS-related terms. Some of This document collects a wide variety of DNS-related terms. Some of
them have been precisely defined in earlier RFCs, some have been them have been precisely defined in earlier RFCs, some have been
loosely defined in earlier RFCs, and some are not defined in any loosely defined in earlier RFCs, and some are not defined in any
earlier RFC at all. earlier RFC at all.
The definitions here are believed to be the consensus definition of Most of the definitions here are believed to be the consensus
the DNS community, both protocol developers and operators. Some of definition of the DNS community - both protocol developers and
the definitions differ from earlier RFCs, and those differences are operators. Some of the definitions differ from earlier RFCs, and
noted. The terms are organized loosely by topic. Some definitions those differences are noted. In this document, where the consensus
are for new terms for things that are commonly talked about in the definition is the same as the one in an RFC, that RFC is quoted.
DNS community but that never had terms defined for them. Where the consensus definition has changed somewhat, the RFC is
mentioned but the new stand-alone definition is given.
During the development of this document, it became clear that some It is important to note that, during the development of this
DNS-related terms are interpreted quite differently by different DNS document, it became clear that some DNS-related terms are interpreted
experts. Further, some terms that are defined in early DNS RFCs now quite differently by different DNS experts. Further, some terms that
have definitions that are generally agreed to that are different from are defined in early DNS RFCs now have definitions that are generally
the original definitions. Therefore, the authors intend to follow agreed to, but that are different from the original definitions.
this document with a substantial revision in the not-distant future. Therefore, the authors intend to follow this document with a
That revision will probably have more in-depth discussion of some substantial revision in the not-distant future. That revision will
terms as well as new terms; it will also update some of the RFCs with probably have more in-depth discussion of some terms as well as new
new definitions. terms; it will also update some of the RFCs with new definitions.
In this document, where the consensus definition is the same as the The terms are organized loosely by topic. Some definitions are for
one in an RFC, that RFC is quoted. Where the consensus definition new terms for things that are commonly talked about in the DNS
has changed somewhat, the RFC is mentioned but the new stand-alone community but that never had terms defined for them.
definition is given.
Other organizations sometimes define DNS-related terms their own way. Other organizations sometimes define DNS-related terms their own way.
For example, the W3C defines "domain" at For example, the W3C defines "domain" at
https://specs.webplatform.org/url/webspecs/develop/. https://specs.webplatform.org/url/webspecs/develop/.
Note that there is no single consistent definition of "the DNS". It Note that there is no single consistent definition of "the DNS". It
can be considered to be some combination of the following: a can be considered to be some combination of the following: a
commonly-used naming scheme for objects on the Internet; a database commonly-used naming scheme for objects on the Internet; a
representing the names and certain properties of these objects; an distributed database representing the names and certain properties of
architecture providing distributed maintenance, resilience, and loose these objects; an architecture providing distributed maintenance,
coherency for this database; and a simple query-response protocol (as resilience, and loose coherency for this database; and a simple
mentioned below) implementing this architecture. query-response protocol (as mentioned below) implementing this
architecture.
Capitalization in DNS terms is often inconsistent between RFCs and Capitalization in DNS terms is often inconsistent among RFCs and
between DNS practitioners. The capitalization used in this document various DNS practitioners. The capitalization used in this document
is a best guess at current practices, and is not meant to indicate is a best guess at current practices, and is not meant to indicate
that other capitalization styles are wrong or archaic. In some that other capitalization styles are wrong or archaic. In some
cases, multiple styles of capitalization are used for the same term cases, multiple styles of capitalization are used for the same term
due to quoting from different RFCs. due to quoting from different RFCs.
2. Names 2. Names
Domain name: Section 3.1 of [RFC1034] talks of "the domain name Domain name: Section 3.1 of [RFC1034] talks of "the domain name
space" as a tree structure. "Each node has a label, which is zero space" as a tree structure. "Each node has a label, which is zero
to 63 octets in length. ... The domain name of a node is the list to 63 octets in length. ... The domain name of a node is the list
of the labels on the path from the node to the root of the tree. of the labels on the path from the node to the root of the tree.
... To simplify implementations, the total number of octets that ... To simplify implementations, the total number of octets that
represent a domain name (i.e., the sum of all label octets and represent a domain name (i.e., the sum of all label octets and
label lengths) is limited to 255." label lengths) is limited to 255." Any label in a domain name can
contain any octet value.
Fully-qualified domain name (FQDN): This is often just a clear way Fully-qualified domain name (FQDN): This is often just a clear way
of saying the same thing as "domain name of a node", as outlined of saying the same thing as "domain name of a node", as outlined
above. However, the term is ambiguous. Strictly speaking, a above. However, the term is ambiguous. Strictly speaking, a
fully-qualified name would include every label, including the fully-qualified domain name would include every label, including
final, zero-length label of the root zone: such a name would be the final, zero-length label of the root: such a name would be
written "www.example.net." (note the terminating dot). But written "www.example.net." (note the terminating dot). But
because every name eventually shares the common root, names are because every name eventually shares the common root, names are
often written relative to the root (such as "www.example.net") and often written relative to the root (such as "www.example.net") and
are still called "fully qualified". are still called "fully qualified".
This term first appeared in [RFC1206]. This term first appeared in [RFC0819].
The need for the term "fully-qualified domain name" comes from the The need for the term "fully-qualified domain name" comes from the
existence of partially-qualified domain names, which are names existence of partially-qualified domain names, which are names
where some of the right-most names are left off and are understood where some of the right-most names are left off and are understood
only by context. only by context.
Label: The identifier of an individual node in the sequence of nodes Label: The identifier of an individual node in the sequence of nodes
that comprise a fully-qualified domain name. identified by a fully-qualified domain name.
Host name: This term and its equivalent, "hostname", have been Host name: This term and its equivalent, "hostname", have been
widely used but are not defined in [RFC1034], [RFC1035], widely used but are not defined in [RFC1034], [RFC1035],
[RFC1123], or [RFC2181]. The DNS was originally deployed into the [RFC1123], or [RFC2181]. The DNS was originally deployed into the
Host Tables environment as outlined in [RFC0952], and it is likely Host Tables environment as outlined in [RFC0952], and it is likely
that the term followed informally from the definition there. Over that the term followed informally from the definition there. Over
time, the definition seems to have shifted. "Host name" is often time, the definition seems to have shifted. "Host name" is often
meant to be a domain name that follows the rules in Section 3.5 of meant to be a domain name that follows the rules in Section 3.5 of
[RFC1034], the "preferred name syntax". Note that any label in [RFC1034], the "preferred name syntax". Note that any label in a
any domain name can contain any octet value; hostnames are domain name can contain any octet value; hostnames are generally
generally considered to be domain names where every label follows considered to be domain names where every label follows the rules
the rules in the "preferred name syntax", with the amendment that in the "preferred name syntax", with the amendment that labels can
labels can start with ASCII digits (this amendment comes from start with ASCII digits (this amendment comes from Section 2.1 of
Section 2.1 of [RFC1123]). [RFC1123]).
People also sometimes use the term hostname to refer to just the People also sometimes use the term hostname to refer to just the
first label of an FQDN. In addition, people sometimes use this first label of an FQDN, such as "printer" in
term to describe any name that refers to a machine, and those "printer.admin.example.com". (Sometimes this is formalized in
might include labels that do not conform to the "preferred name configuration in operating systems.) In addition, people
syntax". sometimes use this term to describe any name that refers to a
machine, and those might include labels that do not conform to the
"preferred name syntax".
TLD: A Top-Level Domain, meaning a zone that is one layer below the TLD: A Top-Level Domain, meaning a zone that is one layer below the
root, such as .com or .jp. There is nothing special, from the root, such as "com" or "jp". There is nothing special, from the
point of view of the DNS, about TLDs. Most of them are also point of view of the DNS, about TLDs. Most of them are also
delegation-centric zones, and there are significant policy issues delegation-centric zones, and there are significant policy issues
around their operation. TLDs are often divided into sub-groups around their operation. TLDs are often divided into sub-groups
such as "ccTLDs", "gTLDs", and others; the division is a matter of such as "ccTLDs", "gTLDs", and others; the division is a matter of
policy, and beyond the scope of this document. policy, and beyond the scope of this document.
IDN: The common abbreviation for "internationalized domain name". IDN: The common abbreviation for "internationalized domain name".
IDNs are the current standard mechanism for handling domain names The IDNA protocol is the standard mechanism for handling domain
with non-ASCII characters in applications. The current standard, names with non-ASCII characters in applications in the DNS. The
normally called "IDNA2008", is defined in [RFC5890], [RFC5891], current standard, normally called "IDNA2008", is defined in
[RFC5892], [RFC5893], and [RFC5894]. These documents define many
IDN-specific terms such as "LDH label", "A-label", and "U-label". [RFC5890], [RFC5891], [RFC5892], [RFC5893], and [RFC5894]. These
documents define many IDN-specific terms such as "LDH label",
"A-label", and "U-label". [RFC6365] defines more terms that
relate to internationalization (some of which relate to IDNs), and
[RFC6055] has a much more extensive discussion of IDNs, including
some new terminology.
Subdomain: A domain is a subdomain of another domain if it is
contained within that domain. This relationship can be tested by
seeing if the subdomain's name ends with the containing domain's
name. (Quoted from [RFC1034], section 3.1) For example, in the
host name "nnn.mmm.example.com", both "mmm.example.com" and
"nnn.mmm.example.com" are subdomains of "example.com".
Alias: The owner of a CNAME resource record, or a subdomain of the Alias: The owner of a CNAME resource record, or a subdomain of the
owner of a DNAME resource record [RFC6672]. See also "canonical owner of a DNAME resource record [RFC6672]. See also "canonical
name". name".
Canonical name: A CNAME resource record identifies its owner name as Canonical name: A CNAME resource record identifies its owner name as
an alias, and specifies the corresponding canonical name in the an alias, and specifies the corresponding canonical name in the
RDATA section of the RR. (Quoted from [RFC1034], section 3.6.2) RDATA section of the RR. (Quoted from [RFC1034], section 3.6.2)
This usage of the word "canonical" is related to the mathematical This usage of the word "canonical" is related to the mathematical
concept of "canonical form". concept of "canonical form".
CNAME: It is traditional to refer to the owner of a CNAME record as CNAME: It is traditional to refer to the owner of a CNAME record as
"a CNAME". This is unfortunate, as "CNAME" is an abbreviation of "a CNAME". This is unfortunate, as "CNAME" is an abbreviation of
"canonical name", and the owner of a CNAME record is an alias not "canonical name", and the owner of a CNAME record is an alias not
a canonical name. (Quoted from [RFC2181], section 10.1.1) a canonical name. (Quoted from [RFC2181], section 10.1.1)
Public suffix: A domain under which subdomains can be registered, Public suffix: A domain that is controlled by a public registry.
and on which HTTP cookies ([RFC6265]) should not be set. There is (Quoted from [RFC6265], section 5.3) A common definition for this
no indication in a domain name whether or not it is a public term is a domain under which subdomains can be registered, and on
suffix; that can only be determined by outside means. The IETF which HTTP cookies ([RFC6265]) should not be set. There is no
DBOUND Working Group [DBOUND] deals with issues with public indication in a domain name whether it is a public suffix; that
suffixes. can only be determined by outside means. In fact, both a domain
and a subdomain of that domain can be public suffixes. At the
time this document is published, the IETF DBOUND Working Group
[DBOUND] is dealing with issues concerning public suffixes.
For example, at the time this document is published, .com.au is There is nothing inherent in a domain name to indicate whether it
considered a public suffix, but .au is not. (Note that this is a public suffix. One resource for identifying public suffixes
example might change in the future.) is the Public Suffix List (PSL) maintained by Mozilla
(http://publicsuffix.org/).
For example, at the time this document is published, the "au" TLD
is not considered a public suffix, but the "com.au" domain is.
(Note that this example might change in the future.)
Note that the term "public suffix" is controversial in the DNS Note that the term "public suffix" is controversial in the DNS
community for many reasons, and may be significantly changed in community for many reasons, and may be significantly changed in
the future. One example of the difficulty of calling a domain a the future. One example of the difficulty of calling a domain a
public suffix is that designation can change over time as the public suffix is that designation can change over time as the
registration policy for the zone changes, such as the case of the registration policy for the zone changes, such as the case of the
.uk zone around the time this document is published. "uk" TLD around the time this document is published.
3. DNS Header and Response Codes 3. DNS Header and Response Codes
The header of a DNS message is first 12 octets. Many of the fields The header of a DNS message is the first 12 octets. Many of the
and flags in the header diagram in section 4.1.1 of [RFC1035] are fields and flags in the header diagram in sections 4.1.1 through
referred to by their names in that diagram. For example, the 4.1.3 of [RFC1035] are referred to by their names in that diagram.
response codes are called "RCODEs", the data for a record is called For example, the response codes are called "RCODEs", the data for a
the "RDATA", and the authoritative answer bit is often called "the AA record is called the "RDATA", and the authoritative answer bit is
flag" or "the AA bit". often called "the AA flag" or "the AA bit".
Some of response codes that are defined in [RFC1035] have gotten Some of response codes that are defined in [RFC1035] have gotten
their own shorthand names. Some common response code names that their own shorthand names. Some common response code names that
appear without reference to the numeric value are "FORMERR", appear without reference to the numeric value are "FORMERR",
"SERVFAIL", and "NXDOMAIN" (the latter of which is also referred to "SERVFAIL", and "NXDOMAIN" (the latter of which is also referred to
as "Name Error"). All of the RCODEs are listed at as "Name Error"). All of the RCODEs are listed at
http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml, http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml,
although that site uses mixed-case capitalization, while most although that site uses mixed-case capitalization, while most
documents use all-caps. documents use all-caps.
NODATA: A pseudo RCODE which indicates that the name is valid for NODATA: A pseudo RCODE which indicates that the name is valid for
the given class, but are no records of the given type. A NODATA the given class, but there are no records of the given type. A
response has to be inferred from the answer. (Quoted from NODATA response has to be inferred from the answer. (Quoted from
[RFC2308], section 1.) NODATA is indicated by an answer with the [RFC2308], section 1.) NODATA is indicated by an answer with the
RCODE set to NOERROR and no relevant answers in the answer RCODE set to NOERROR and no relevant answers in the answer
section. The authority section will contain an SOA record, or section. The authority section will contain an SOA record, or
there will be no NS records there. (Quoted from [RFC2308], there will be no NS records there. (Quoted from [RFC2308],
section 2,2.) Note that referrals have a similar format to NODATA section 2,2.) Note that referrals have a similar format to NODATA
replies; [RFC2308] explains how to distinguish them. replies; [RFC2308] explains how to distinguish them.
The term "NXRRSET" is sometimes used as a synonym for NODATA. The term "NXRRSET" is sometimes used as a synonym for NODATA.
However, this is a mistake, given that NXRRSET is a specific error However, this is a mistake, given that NXRRSET is a specific error
code defined in [RFC2136]. code defined in [RFC2136].
Negative response: A response which indicates that a particular Negative response: A response which indicates that a particular
RRset does not exist, or whose RCODE indicates the nameserver RRset does not exist, or whose RCODE indicates the nameserver
cannot answer. Sections 2 and 7 of [RFC2308] describe the types cannot answer. Sections 2 and 7 of [RFC2308] describe the types
of negative responses in detail. of negative responses in detail.
Referrals: Data from the authority section of a non-authoritative Referrals: Data from the authority section of a non-authoritative
answer. [RFC1035] section 2.1 defines "authoritative" data. answer. [RFC1035] section 2.1 defines "authoritative" data.
However, referrals at zone cuts are not authoritative. Referrals However, referrals at zone cuts (defined in Section 6) are not
may be a zone cut NS resource records and their glue records. NS authoritative. Referrals may be zone cut NS resource records and
records on the parent side of a zone cut are an authoritative their glue records. NS records on the parent side of a zone cut
delegation, but are normally not treated as authoritative data by are an authoritative delegation, but are normally not treated as
the client. In general, a referral is a way for a server to send authoritative data by the client. In general, a referral is a way
an answer saying that the server does not know the answer, but for a server to send an answer saying that the server does not
knows where the query should be directed in order to get an know the answer, but knows where the query should be directed in
answer. Historically, many authoritative servers answered with a order to get an answer. Historically, many authoritative servers
referral to the root zone when queried for a name for which they answered with a referral to the root zone when queried for a name
were not authoritative, but this practice has declined. for which they were not authoritative, but this practice has
declined.
4. Resource Records 4. Resource Records
RR: A short form for resource record. ([RFC1034], section 3.6.) RR: An acronym for resource record. ([RFC1034], section 3.6.)
RRset: A set of resource records with the same label, class and RRset: A set of resource records with the same label, class and
type, but with different data. (Definition from [RFC2181]) Also type, but with different data. (Definition from [RFC2181]) Also
spelled RRSet in some documents. As a clarification, "same label" spelled RRSet in some documents. As a clarification, "same label"
in this definition means "same owner name". In addition, in this definition means "same owner name". In addition,
[RFC2181] states that "the TTLs of all RRs in an RRSet must be the [RFC2181] states that "the TTLs of all RRs in an RRSet must be the
same". same". (This definition is definitely not the same as "the
response one gets to a query for QTYPE=ANY", which is a
unfortunate misunderstanding.)
EDNS: The extension mechanisms for DNS, defined in [RFC6891]. EDNS: The extension mechanisms for DNS, defined in [RFC6891].
Sometimes called "EDNS0" or "EDNS(0)" to indicate the version Sometimes called "EDNS0" or "EDNS(0)" to indicate the version
number. EDNS allows DNS clients and servers to specify message number. EDNS allows DNS clients and servers to specify message
sizes larger than the original 512 octet limit, to expand the sizes larger than the original 512 octet limit, to expand the
response code space, and to potentially carry additional options response code space, and potentially to carry additional options
that affect the handling of a DNS query. that affect the handling of a DNS query.
OPT: A pseudo-RR (sometimes called a meta-RR) that is used only to OPT: A pseudo-RR (sometimes called a meta-RR) that is used only to
contain control information pertaining to the question-and-answer contain control information pertaining to the question-and-answer
sequence of a specific transaction. (Definition from [RFC6891], sequence of a specific transaction. (Definition from [RFC6891],
section 6.1.1) It is used by EDNS. section 6.1.1) It is used by EDNS.
Owner: The domain name where a RR is found ([RFC1034], section 3.6). Owner: The domain name where a RR is found ([RFC1034], section 3.6).
Often appears in the term "owner name". Often appears in the term "owner name".
SOA field names: DNS documents, including the definitions here, SOA field names: DNS documents, including the definitions here,
often refer to the fields in the RDATA an SOA resource record by often refer to the fields in the RDATA of an SOA resource record
field name. Those fields are defined in Section 3.3.13 of by field name. Those fields are defined in Section 3.3.13 of
[RFC1035]. The names (in the order they appear in the SOA RDATA) [RFC1035]. The names (in the order they appear in the SOA RDATA)
are MNAME, RNAME, SERIAL, REFRESH, RETRY, EXPIRE, and MINIMUM. are MNAME, RNAME, SERIAL, REFRESH, RETRY, EXPIRE, and MINIMUM.
Note that the meaning of MINIMUM field is updated in Section 4 of Note that the meaning of MINIMUM field is updated in Section 4 of
[RFC2308]; the new definition is that the MINIMUM field is only [RFC2308]; the new definition is that the MINIMUM field is only
"the TTL to be used for negative responses". "the TTL to be used for negative responses". This document tends
to use field names instead of terms that describe the fields.
TTL: The maximum "time to live" of a resource record. A TTL value TTL: The maximum "time to live" of a resource record. A TTL value
is an unsigned number, with a minimum value of 0, and a maximum is an unsigned number, with a minimum value of 0, and a maximum
value of 2147483647. That is, a maximum of 2^31 - 1. When value of 2147483647. That is, a maximum of 2^31 - 1. When
transmitted, the TTL is encoded in the less significant 31 bits of transmitted, the TTL is encoded in the less significant 31 bits of
the 32 bit TTL field, with the most significant, or sign, bit set the 32 bit TTL field, with the most significant, or sign, bit set
to zero. (Quoted from [RFC2181], section 8) (Note that [RFC1035] to zero. (Quoted from [RFC2181], section 8) (Note that [RFC1035]
erroneously stated that this is a signed integer; it is fixed in erroneously stated that this is a signed integer; that was fixed
an erratum.) by [RFC2181].)
The TTL "specifies the time interval that the resource record may The TTL "specifies the time interval that the resource record may
be cached before the source of the information should again be be cached before the source of the information should again be
consulted". (Quoted from [RFC1035], section 3.2.1) Also: "the consulted". (Quoted from [RFC1035], section 3.2.1) Also: "the
time interval (in seconds) that the resource record may be cached time interval (in seconds) that the resource record may be cached
before it should be discarded". (Quoted from [RFC1035], section before it should be discarded". (Quoted from [RFC1035], section
4.1.3). Despite being defined for a resource record, the TTL of 4.1.3). Despite being defined for a resource record, the TTL of
every resource record in an RRset is required to be the same every resource record in an RRset is required to be the same
(RFC2181, section 5.2). ([RFC2181], section 5.2).
The reason that the TTL is the maximum time to live is that a The reason that the TTL is the maximum time to live is that a
cache operator might decide to shorten the time to live for cache operator might decide to shorten the time to live for
operational purposes, such as if there is a policy to not allow operational purposes, such as if there is a policy to not allow
TTL values over a certain number. Also, if a value is flushed TTL values over a certain number. Also, if a value is flushed
from the cache when its value is still positive, the value from the cache when its value is still positive, the value
effectively becomes zero. Some servers do not honor the TTL on an effectively becomes zero. Some servers do not honor the TTL on an
RRset from the authoritative servers, such as when when the RRset from the authoritative servers, such as when the
authoritative data has a very short TTL. authoritative data has a very short TTL.
There is also the concept of a "default TTL" for a zone, which can There is also the concept of a "default TTL" for a zone, which can
be a configuration parameter in the server software. This is be a configuration parameter in the server software. This is
often expressed by a default for the entire server, and a default often expressed by a default for the entire server, and a default
for a zone using the $TTL directive in a zone file. The $TTL for a zone using the $TTL directive in a zone file. The $TTL
directive was added to the master file format by [RFC2308]. directive was added to the master file format by [RFC2308].
Class independent: A resource record type whose syntax and semantics Class independent: A resource record type whose syntax and semantics
are the same for every DNS class. A resource record type that is are the same for every DNS class. A resource record type that is
not class independent has different meanings depending on the DNS not class independent has different meanings depending on the DNS
class of the record, or the meaning is undefined for classes other class of the record, or the meaning is undefined for classes other
than IN. than IN (class 1, the Internet).
5. DNS Servers 5. DNS Servers and Clients
This section defines the terms used for the systems that act as DNS This section defines the terms used for the systems that act as DNS
clients, DNS servers, or both. Some terms about servers describe clients, DNS servers, or both.
servers that do and do not use DNSSEC; see Section 8 for those
definitions.
Resolver: A program that extracts information from name servers in Resolver: A program that extracts information from name servers in
response to client requests. (Quoted from [RFC1034], section 2.4) response to client requests. (Quoted from [RFC1034], section 2.4)
The resolver is located on the same machine as the program that The resolver is located on the same machine as the program that
requests the resolver's services, but it may need to consult name requests the resolver's services, but it may need to consult name
servers on other hosts. (Quoted from [RFC1034], section 5.1) A servers on other hosts. (Quoted from [RFC1034], section 5.1) A
resolver performs queries for a name, type, and class, and resolver performs queries for a name, type, and class, and
receives answers. The logical function is called "resolution". receives answers. The logical function is called "resolution".
In practice, the term is usually referring to some specific type In practice, the term is usually referring to some specific type
of resolver (some of which are defined below), and understanding of resolver (some of which are defined below), and understanding
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operating in this mode are commonly called "recursive servers". operating in this mode are commonly called "recursive servers".
Sometimes they are called "recursive resolvers". While strictly Sometimes they are called "recursive resolvers". While strictly
the difference between these is that one of them sends queries to the difference between these is that one of them sends queries to
another recursive server and the other does not, in practice it is another recursive server and the other does not, in practice it is
not possible to know in advance whether the server that one is not possible to know in advance whether the server that one is
querying will also perform recursion; both terms can be observed querying will also perform recursion; both terms can be observed
in use interchangeably. in use interchangeably.
Full resolver: This term is used in [RFC1035], but it is not defined Full resolver: This term is used in [RFC1035], but it is not defined
there. RFC 1123 defines a "full-service resolver" that may or may there. RFC 1123 defines a "full-service resolver" that may or may
not be what was intended by "full resolver" in [RFC1035]. not be what was intended by "full resolver" in [RFC1035]. This
term is not properly defined in any RFC.
Full-service resolver: Section 6.1.3.1 of [RFC1123] defines this Full-service resolver: Section 6.1.3.1 of [RFC1123] defines this
term to mean a resolver that acts in recursive mode with a cache term to mean a resolver that acts in recursive mode with a cache
(and meets other requirements). (and meets other requirements).
Priming: The mechanism used by a resolver to determine where to send Priming: The mechanism used by a resolver to determine where to send
queries before there is anything in the resolver's cache. Priming queries before there is anything in the resolver's cache. Priming
is most often done from a configuration setting that contains a is most often done from a configuration setting that contains a
list of authoritative servers for the DNS root zone. list of authoritative servers for the root zone.
Negative caching: The storage of knowledge that something does not Negative caching: The storage of knowledge that something does not
exist, cannot give an answer, or does not give an answer. (Quoted exist, cannot give an answer, or does not give an answer. (Quoted
from [RFC2308], section 1) from [RFC2308], section 1)
Authoritative server: A server that knows the content of a DNS zone Authoritative server: A server that knows the content of a DNS zone
from local knowledge, and thus can answer queries about that zone from local knowledge, and thus can answer queries about that zone
without needing to query other servers. (Quoted from [RFC2182], without needing to query other servers. (Quoted from [RFC2182],
section 2.) It is a system that responds to DNS queries with section 2.) It is a system that responds to DNS queries with
information about zones for which it has been configured to answer information about zones for which it has been configured to answer
with the AA flag in the response header set to 1. It is a server with the AA flag in the response header set to 1. It is a server
that has authority over one or more DNS zones. Note that it is that has authority over one or more DNS zones. Note that it is
possible for an authoritative server to respond to a query without possible for an authoritative server to respond to a query without
the parent zone delegating authority to that server. the parent zone delegating authority to that server.
Authoritative servers also provide "referrals", usually to child Authoritative servers also provide "referrals", usually to child
zones delegated from them; these referrals have the AA bit set to zones delegated from them; these referrals have the AA bit set to
0 and come with referral data in the Authority and (if needed) the 0 and come with referral data in the Authority and (if needed) the
Additional sections. Additional sections.
Authoritative-only server: A name server which only serves Authoritative-only server: A name server that only serves
authoritative data and ignore requests for recursion. It will not authoritative data and ignores requests for recursion. It will
normally generate any queries of its own. Instead, it answers "not normally generate any queries of its own. Instead, it
non-recursive queries from iterative resolvers looking for answers non-recursive queries from iterative resolvers looking for
information in zones it serves. (Quoted from [RFC4697], section information in zones it serves." (Quoted from [RFC4697], section
2.4) 2.4)
Zone transfer: The act of a client requesting a copy of a zone and Zone transfer: The act of a client requesting a copy of a zone and
an authoritative server sending the needed information. There are an authoritative server sending the needed information. (See
two common standard ways to do zone transfers: the AXFR Section 6 for a description of zones.) There are two common
("Authoritative Transfer") mechanism to copy the full zone standard ways to do zone transfers: the AXFR ("Authoritative
(described in [RFC5936], and the IXFR ("Incremental Transfer") Transfer") mechanism to copy the full zone (described in
mechanism to copy only parts of the zone that have changed [RFC5936], and the IXFR ("Incremental Transfer") mechanism to copy
(described in [RFC1995]). Many systems use non-standard methods only parts of the zone that have changed (described in [RFC1995]).
for zone transfer outside the DNS protocol. Many systems use non-standard methods for zone transfer outside
the DNS protocol.
Secondary server: "An authoritative server which uses zone transfer Secondary server: "An authoritative server which uses zone transfer
to retrieve the zone" (quoted from [RFC1996], section 2.1). to retrieve the zone" (quoted from [RFC1996], section 2.1).
[RFC2182] describes secondary servers in detail. Although early [RFC2182] describes secondary servers in detail. Although early
DNS RFCs such as [RFC1996] referred to this as a "slave", the DNS RFCs such as [RFC1996] referred to this as a "slave", the
current common usage has shifted to calling it a "secondary". current common usage has shifted to calling it a "secondary".
Secondary servers are also discussed in [RFC1034].
Slave server: See secondary server. Slave server: See secondary server.
Primary server: "Any authoritative server configured to be the Primary server: "Any authoritative server configured to be the
source of zone transfer for one or more [secondary] servers" source of zone transfer for one or more [secondary] servers"
(quoted from [RFC1996], section 2.1) or, more specifically, "an (quoted from [RFC1996], section 2.1) or, more specifically, "an
authoritative server configured to be the source of AXFR or IXFR authoritative server configured to be the source of AXFR or IXFR
data for one or more [secondary] servers" (quoted from [RFC2136]). data for one or more [secondary] servers" (quoted from [RFC2136]).
Although early DNS RFCs such as [RFC1996] referred to this as a Although early DNS RFCs such as [RFC1996] referred to this as a
"master", the current common usage has shifted to "primary". "master", the current common usage has shifted to "primary".
Primary servers are also discussed in [RFC1034].
Master server: See primary server. Master server: See primary server.
Primary master: The primary master is named in the zone's SOA MNAME Primary master: The primary master is named in the zone's SOA MNAME
field and optionally by an NS resource record. (Quoted from field and optionally by an NS resource record. (Quoted from
[RFC1996], section 2.1) [RFC2136] defines "primary master" as [RFC1996], section 2.1) [RFC2136] defines "primary master" as
"Master server at the root of the AXFR/IXFR dependency graph. The "Master server at the root of the AXFR/IXFR dependency graph. The
primary master is named in the zone's SOA MNAME field and primary master is named in the zone's SOA MNAME field and
optionally by an NS RR. There is by definition only one primary optionally by an NS RR. There is by definition only one primary
master server per zone." The idea of a primary master is only master server per zone." The idea of a primary master is only
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resolvers." That definition appears to suggest that forwarders resolvers." That definition appears to suggest that forwarders
normally only query authoritative servers. In current use, normally only query authoritative servers. In current use,
however, forwarders often stand between stub resolvers and however, forwarders often stand between stub resolvers and
recursive servers. [RFC2308] is silent on whether a forwarder is recursive servers. [RFC2308] is silent on whether a forwarder is
iterative-only or can be a full-service resolver. iterative-only or can be a full-service resolver.
Policy-implementing resolver: A resolver acting in recursive mode Policy-implementing resolver: A resolver acting in recursive mode
that changes some of the answers that it returns based on policy that changes some of the answers that it returns based on policy
criteria, such as to prevent access to malware sites or criteria, such as to prevent access to malware sites or
objectionable content. In general, a stub resolver has no idea objectionable content. In general, a stub resolver has no idea
whether or not upstream resolvers implement such policy or, if whether upstream resolvers implement such policy or, if they do,
they do, the exact policy about what changes will be made. In the exact policy about what changes will be made. In some cases,
some cases, the user of the stub resolver has selected the policy- the user of the stub resolver has selected the policy-implementing
implementing resolver with the explicit intention of using it to resolver with the explicit intention of using it to implement the
implement the policies. In other cases, policies are imposed policies. In other cases, policies are imposed without the user
without the user of the stub resolver being informed. of the stub resolver being informed.
Open resolver: A full-service resolver that accepts and processes Open resolver: A full-service resolver that accepts and processes
queries from any (or nearly any) stub resolver. This is sometimes queries from any (or nearly any) stub resolver. This is sometimes
also called a "public resolver", although the term "public also called a "public resolver", although the term "public
resolver" is used more with open resolvers that are meant to be resolver" is used more with open resolvers that are meant to be
open, as compared to the vast majority of open resolvers that are open, as compared to the vast majority of open resolvers that are
probably misconfigured to be open. probably misconfigured to be open.
View: A configuration for a DNS server that allows it to provide View: A configuration for a DNS server that allows it to provide
different answers depending on attributes of the query. different answers depending on attributes of the query.
Typically, views differ by the source IP address of a query, but Typically, views differ by the source IP address of a query, but
can also be based on the destination IP address, the type of query can also be based on the destination IP address, the type of query
(such as AXFR), whether or not it is recursive, and so on. Views (such as AXFR), whether it is recursive, and so on. Views are
are often used to provide more names or different addresses to often used to provide more names or different addresses to queries
queries from "inside" a protected network than to those "outside" from "inside" a protected network than to those "outside" that
that network. Views are not a standardized part of the DNS, but network. Views are not a standardized part of the DNS, but they
they are widely implemented in server software. are widely implemented in server software.
Passive DNS: A mechanism to collect large amounts of DNS data by Passive DNS: A mechanism to collect large amounts of DNS data by
storing DNS responses from servers. Some of these systems also storing DNS responses from servers. Some of these systems also
collect the DNS queries associated with the responses; this can collect the DNS queries associated with the responses; this can
raise privacy issues. Passive DNS databases can be used to answer raise privacy issues. Passive DNS databases can be used to answer
historical questions about DNS zones such as which records were historical questions about DNS zones such as which records were
available for them at what times in the past. Passive DNS available for them at what times in the past. Passive DNS
databases allow searching of the stored records on keys other than databases allow searching of the stored records on keys other than
just the name, such as "find all names which have A records of a just the name, such as "find all names which have A records of a
particular value". particular value".
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(Quoted from [RFC4786], Section 2) (Quoted from [RFC4786], Section 2)
6. Zones 6. Zones
This section defines terms that are used when discussing zones that This section defines terms that are used when discussing zones that
are being served or retrieved. are being served or retrieved.
Zone: A unit of organization of authoritative data. Zones can be Zone: A unit of organization of authoritative data. Zones can be
automatically distributed to the name servers which provide automatically distributed to the name servers which provide
redundant service for the data in a zone. (Quoted from [RFC1034], redundant service for the data in a zone. (Quoted from [RFC1034],
section 2.4). section 2.4)
Child: The entity on record that has the delegation of the domain Child: The entity on record that has the delegation of the domain
from the Parent. (Quoted from [RFC7344], section 1.1) from the Parent. (Quoted from [RFC7344], section 1.1)
Parent: The domain in which the Child is registered. (Quoted from Parent: The domain in which the Child is registered. (Quoted from
[RFC7344], section 1.1) Earlier, "parent name server" was defined [RFC7344], section 1.1) Earlier, "parent name server" was defined
in [RFC0882] as "the name server that has authority over the place in [RFC0882] as "the name server that has authority over the place
in the domain name space that will hold the new domain". in the domain name space that will hold the new domain".
[RFC0819] also has some description of the relationship between
parents and children.
Origin: Origin:
(a) The domain name that appears at the top of a zone (just below (a) The domain name that appears at the top of a zone (just below
the cut that separates the zone from its parent). The name of the the cut that separates the zone from its parent). The name of the
zone is the same as the name of the domain at the zone's origin. zone is the same as the name of the domain at the zone's origin.
(Quoted from [RFC2181], section 6.) These days, this sense of (Quoted from [RFC2181], section 6.) These days, this sense of
"origin" and "apex" (defined below) are often used "origin" and "apex" (defined below) are often used
interchangeably. interchangeably.
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"www" is in fact an entry for "www.example.org.". "www" is in fact an entry for "www.example.org.".
Apex: The point in the tree at an owner of an SOA and corresponding Apex: The point in the tree at an owner of an SOA and corresponding
authoritative NS RRset. This is also called the "zone apex". authoritative NS RRset. This is also called the "zone apex".
[RFC4033] defines it as "the name at the child's side of a zone [RFC4033] defines it as "the name at the child's side of a zone
cut". The "apex" can usefully be thought of as a data-theoretic cut". The "apex" can usefully be thought of as a data-theoretic
description of a tree structure, and "origin" is the name of the description of a tree structure, and "origin" is the name of the
same concept when it is implemented in zone files. The same concept when it is implemented in zone files. The
distinction is not always maintained in use, however, and one can distinction is not always maintained in use, however, and one can
find uses that conflict subtly with this definition. [RFC1034] find uses that conflict subtly with this definition. [RFC1034]
uses the term "top node of the zone" instead of "apex". These uses the term "top node of the zone" as a synonym of "apex", but
days, the first sense of "origin" (above) and "apex" are often that term is not widely used. These days, the first sense of
used interchangeably. "origin" (above) and "apex" are often used interchangeably.
Zone cut: The delimitation point between two zones where the origin Zone cut: The delimitation point between two zones where the origin
of one of the zones is the child of the other zone. of one of the zones is the child of the other zone.
Zones are delimited by "zone cuts". Each zone cut separates a Zones are delimited by "zone cuts". Each zone cut separates a
"child" zone (below the cut) from a "parent" zone (above the cut). "child" zone (below the cut) from a "parent" zone (above the cut).
(Quoted from [RFC2181], section 6; note that this is barely an (Quoted from [RFC2181], section 6; note that this is barely an
ostensive definition.) Section 4.2 of [RFC1034] uses "cuts" as ostensive definition.) Section 4.2 of [RFC1034] uses "cuts" as
"zone cut". "zone cut".
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data that might appear" ([RFC2181], section 5.4.1). Although glue data that might appear" ([RFC2181], section 5.4.1). Although glue
is sometimes used today with this wider definition in mind, the is sometimes used today with this wider definition in mind, the
context surrounding the [RFC2181] definition suggests it is context surrounding the [RFC2181] definition suggests it is
intended to apply to the use of glue within the document itself intended to apply to the use of glue within the document itself
and not necessarily beyond. and not necessarily beyond.
In-bailiwick: In-bailiwick:
(a) An adjective to describe a name server whose name is either (a) An adjective to describe a name server whose name is either
subordinate to or (rarely) the same as the zone origin. In- subordinate to or (rarely) the same as the zone origin. In-
bailiwick name servers require glue in their parent zone. bailiwick name servers require glue records in their parent zone
(using the first of the definitions of "glue records" in the
definition above).
(b) Data for which the server is either authoritative, or else (b) Data for which the server is either authoritative, or else
authoritative for an ancestor of the owner name. This sense of authoritative for an ancestor of the owner name. This sense of
the term normally is used when discussing the relevancy of glue the term normally is used when discussing the relevancy of glue
records in a response. For example, the server for the parent records in a response. For example, the server for the parent
zone example.com might reply with glue records for zone "example.com" might reply with glue records for
ns.child.example.com. Because the child.example.com zone is a "ns.child.example.com". Because the "child.example.com" zone is a
descendant of the example.com zone, the glue records are in- descendant of the "example.com" zone, the glue records are in-
bailiwick. bailiwick.
Out-of-bailiwick: The antonym of in-bailiwick. Out-of-bailiwick: The antonym of in-bailiwick.
Authoritative data: All of the RRs attached to all of the nodes from Authoritative data: All of the RRs attached to all of the nodes from
the top node of the zone down to leaf nodes or nodes above cuts the top node of the zone down to leaf nodes or nodes above cuts
around the bottom edge of the zone. (Quoted from [RFC1034], around the bottom edge of the zone. (Quoted from [RFC1034],
section 4.2.1) It is noted that this definition might section 4.2.1) It is noted that this definition might
inadvertently also include any NS records that appear in the zone, inadvertently also include any NS records that appear in the zone,
even those that might not truly be authoritative because there are even those that might not truly be authoritative because there are
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an extended discussion of wildcards, including clearer an extended discussion of wildcards, including clearer
definitions, see [RFC4592]. definitions, see [RFC4592].
Occluded name: The addition of a delegation point via dynamic update Occluded name: The addition of a delegation point via dynamic update
will render all subordinate domain names to be in a limbo, still will render all subordinate domain names to be in a limbo, still
part of the zone but not available to the lookup process. The part of the zone but not available to the lookup process. The
addition of a DNAME resource record has the same impact. The addition of a DNAME resource record has the same impact. The
subordinate names are said to be "occluded". (Quoted from subordinate names are said to be "occluded". (Quoted from
[RFC5936], Section 3.5) [RFC5936], Section 3.5)
Fast flux DNS: This occurs when a domain is bound in DNS using A Fast flux DNS: This occurs when a domain is found in DNS using A
records to multiple IP addresses, each of which has a very short records to multiple IP addresses, each of which has a very short
Time-to-Live (TTL) value associated with it. This means that the Time-to-Live (TTL) value associated with it. This means that the
domain resolves to varying IP addresses over a short period of domain resolves to varying IP addresses over a short period of
time. (Quoted from [RFC6561], section 1.1.5) It is often to time. (Quoted from [RFC6561], section 1.1.5, with typo corrected)
deliver malware. Because the addresses change so rapidly, it is It is often used to deliver malware. Because the addresses change
difficult to definitively find all the hosts. It should be noted so rapidly, it is difficult to acertain all the hosts. It should
that the technique also works with AAAA records, but such use is be noted that the technique also works with AAAA records, but such
not frequently observed on the Internet as of this writing. use is not frequently observed on the Internet as of this writing.
7. Registration Model 7. Registration Model
Registry: The administrative operation of a zone that allows Registry: The administrative operation of a zone that allows
registration of names within that zone. People often use this registration of names within that zone. People often use this
term to refer only to those organizations that perform term to refer only to those organizations that perform
registration in large delegation-centric zones (such as TLDs); but registration in large delegation-centric zones (such as TLDs); but
formally, whoever decides what data goes into a zone is the formally, whoever decides what data goes into a zone is the
registry for that zone. registry for that zone. This definition of "registry" is from a
DNS point of view; for some zones, the policies that determine
what can go in the zone are decided by superior zones and not the
registry operator.
Registrant: An individual or organization on whose behalf a name in Registrant: An individual or organization on whose behalf a name in
a zone is registered by the registry. In many zones, the registry a zone is registered by the registry. In many zones, the registry
and the registrant may be the same entity, but in TLDs they often and the registrant may be the same entity, but in TLDs they often
are not. are not.
Registrar: A service provider that acts as a go-between for Registrar: A service provider that acts as a go-between for
registrants and registries. Not all registrations require a registrants and registries. Not all registrations require a
registrar, though it is common to have registrars be involved in registrar, though it is common to have registrars be involved in
registrations in TLDs. registrations in TLDs.
EPP: The Extensible Provisioning Protocol (EPP), which is commonly EPP: The Extensible Provisioning Protocol (EPP), which is commonly
used for communication of registration information between used for communication of registration information between
registries and registrars. EPP is defined in [RFC5730]. registries and registrars. EPP is defined in [RFC5730].
WHOIS: A protocol specified in [RFC3912], often used for querying WHOIS: A protocol specified in [RFC3912], often used for querying
registry databases. WHOIS data is frequently used to associate registry databases. WHOIS data is frequently used to associate
registration data (such as zone management contacts) with domain registration data (such as zone management contacts) with domain
names. names. The term "WHOIS data" is often used as a synonym for the
registry database, even though that database may be served by
different protocols, particularly RDAP. The WHOIS protocol is
also used with IP address registry data.
RDAP: The Registration Data Access Protocol, defined in [RFC7480],
[RFC7481], [RFC7482], [RFC7483], [RFC7484], and [RFC7485]. The
RDAP protocol and data format are meant as a replacement for
WHOIS.
DNS operator: An entity responsible for running DNS servers. For a DNS operator: An entity responsible for running DNS servers. For a
zone's authoritative servers, the registrant may act as their own zone's authoritative servers, the registrant may act as their own
DNS operator, or their registrar may do it on their behalf, or DNS operator, or their registrar may do it on their behalf, or
they may use a third-party operator. they may use a third-party operator. For some zones, the registry
function is performed by the DNS operator plus other entities who
decide about the allowed contents of the zone.
8. General DNSSEC 8. General DNSSEC
Most DNSSEC terms are defined in [RFC4033], [RFC4034], [RFC4035], and Most DNSSEC terms are defined in [RFC4033], [RFC4034], [RFC4035], and
[RFC5155]. The terms that have caused confusion in the DNS community [RFC5155]. The terms that have caused confusion in the DNS community
are highlighted here. are highlighted here.
DNSSEC-aware and DNSSEC-unaware: Section 2 of [RFC4033] defines many DNSSEC-aware and DNSSEC-unaware: Section 2 of [RFC4033] defines many
types of resolvers and validators, including "non-validating types of resolvers and validators, including "non-validating
security-aware stub resolver", "non-validating stub resolver", security-aware stub resolver", "non-validating stub resolver",
"security-aware name server", "security-aware recursive name "security-aware name server", "security-aware recursive name
server", "security-aware resolver", "security-aware stub server", "security-aware resolver", "security-aware stub
resolver", and "security-oblivious 'anything'". (Note that the resolver", and "security-oblivious 'anything'". However, "DNSSEC-
term "validating resolver", which is used in some places in those aware" and "DNSSEC-unaware" are used in later RFCs, but never
documents, is nevertheless not defined in that section.) formally defined. (Note that the term "validating resolver",
which is used in some places in those documents, is nevertheless
not defined in that section.)
Signed zone: A zone whose RRsets are signed and that contains Signed zone: A zone whose RRsets are signed and that contains
properly constructed DNSKEY, Resource Record Signature (RRSIG), properly constructed DNSKEY, Resource Record Signature (RRSIG),
Next Secure (NSEC), and (optionally) DS records. (Quoted from Next Secure (NSEC), and (optionally) DS records. (Quoted from
[RFC4033], section 2.) It has been noted in other contexts that [RFC4033], section 2.) It has been noted in other contexts that
the zone itself is not really signed, but all the relevant RRsets the zone itself is not really signed, but all the relevant RRsets
in the zone are signed. Nevertheless, if a zone that should be in the zone are signed. Nevertheless, if a zone that should be
signed contains any RRsets that are not signed (or opted out), signed contains any RRsets that are not signed (or opted out),
those RRsets will be treated as bogus, so the whole zone needs to those RRsets will be treated as bogus, so the whole zone needs to
be handled in some way. be handled in some way.
skipping to change at page 17, line 4 skipping to change at page 18, line 8
additional background commentary and some context for the NSEC and additional background commentary and some context for the NSEC and
NSEC3 mechanisms used by DNSSEC to provide authenticated denial- NSEC3 mechanisms used by DNSSEC to provide authenticated denial-
of-existence responses. of-existence responses.
Unsigned zone: Section 2 of [RFC4033] defines this as "a zone that Unsigned zone: Section 2 of [RFC4033] defines this as "a zone that
is not signed". Section 2 of [RFC4035] defines this as "A zone is not signed". Section 2 of [RFC4035] defines this as "A zone
that does not include these records [properly constructed DNSKEY, that does not include these records [properly constructed DNSKEY,
Resource Record Signature (RRSIG), Next Secure (NSEC), and Resource Record Signature (RRSIG), Next Secure (NSEC), and
(optionally) DS records] according to the rules in this section". (optionally) DS records] according to the rules in this section".
There is an important note at the end of Section 5.2 of [RFC4035] There is an important note at the end of Section 5.2 of [RFC4035]
adding an additional situation when a zone is considered unsigned: that defines an additional situation in which a zone is considered
"If the resolver does not support any of the algorithms listed in unsigned: "If the resolver does not support any of the algorithms
an authenticated DS RRset, then the resolver will not be able to listed in an authenticated DS RRset, then the resolver will not be
verify the authentication path to the child zone. In this case, able to verify the authentication path to the child zone. In this
the resolver SHOULD treat the child zone as if it were unsigned." case, the resolver SHOULD treat the child zone as if it were
unsigned."
NSEC: "The NSEC record allows a security-aware resolver to NSEC: "The NSEC record allows a security-aware resolver to
authenticate a negative reply for either name or type non- authenticate a negative reply for either name or type non-
existence with the same mechanisms used to authenticate other DNS existence with the same mechanisms used to authenticate other DNS
replies." (Quoted from [RFC4033], section 3.2.) In short, an replies." (Quoted from [RFC4033], section 3.2.) In short, an
NSEC record provides authenticated denial of existence. NSEC record provides authenticated denial of existence.
The NSEC resource record lists two separate things: the next owner The NSEC resource record lists two separate things: the next owner
name (in the canonical ordering of the zone) that contains name (in the canonical ordering of the zone) that contains
authoritative data or a delegation point NS RRset, and the set of authoritative data or a delegation point NS RRset, and the set of
RR types present at the NSEC RR's owner name. (Quoted from RR types present at the NSEC RR's owner name. (Quoted from
Section 4 of 4034) Section 4 of 4034)
NSEC3: Like the NSEC record, the NSEC3 record also provides NSEC3: Like the NSEC record, the NSEC3 record also provides
authenticated denial of existence; however, NSEC3 records authenticated denial of existence; however, NSEC3 records mitigate
mitigates against zone enumeration and support Opt-Out. NSEC3 against zone enumeration and support Opt-Out. NSEC3 resource
resource records are defined in [RFC5155]. records are defined in [RFC5155].
Note that [RFC6840] says that [RFC5155] "is now considered part of Note that [RFC6840] says that [RFC5155] "is now considered part of
the DNS Security Document Family as described by Section 10 of the DNS Security Document Family as described by Section 10 of
[RFC4033]". This means that some of the definitions from earlier [RFC4033]". This means that some of the definitions from earlier
RFCs that only talk about NSEC records should probably be RFCs that only talk about NSEC records should probably be
considered to be talking about both NSEC and NSEC3. considered to be talking about both NSEC and NSEC3.
Opt-out: The Opt-Out Flag indicates whether this NSEC3 RR may cover Opt-out: The Opt-Out Flag indicates whether this NSEC3 RR may cover
unsigned delegations. (Quoted from [RFC5155], section 3.1.2.1.) unsigned delegations. (Quoted from [RFC5155], section 3.1.2.1.)
Opt-out tackles the high costs of securing a delegation to an Opt-out tackles the high costs of securing a delegation to an
skipping to change at page 18, line 52 skipping to change at page 20, line 10
that may support and be a supplemental document to the DNSSEC that may support and be a supplemental document to the DNSSEC
Policy (if such exists), and it states how the management of a Policy (if such exists), and it states how the management of a
given zone implements procedures and controls at a high level. given zone implements procedures and controls at a high level.
(Quoted from [RFC6841], section 2) (Quoted from [RFC6841], section 2)
9. DNSSEC States 9. DNSSEC States
A validating resolver can determine that a response is in one of four A validating resolver can determine that a response is in one of four
states: secure, insecure, bogus, or indeterminate. These states are states: secure, insecure, bogus, or indeterminate. These states are
defined in [RFC4033] and [RFC4035], although the two definitions defined in [RFC4033] and [RFC4035], although the two definitions
differ a bit. differ a bit. This document makes no effort to reconcile the two
definitions, and takes no position as to whether they need to be
reconciled.
Section 5 of [RFC4033] says: Section 5 of [RFC4033] says:
A validating resolver can determine the following 4 states: A validating resolver can determine the following 4 states:
Secure: The validating resolver has a trust anchor, has a chain of Secure: The validating resolver has a trust anchor, has a chain of
trust, and is able to verify all the signatures in the response. trust, and is able to verify all the signatures in the response.
Insecure: The validating resolver has a trust anchor, a chain of Insecure: The validating resolver has a trust anchor, a chain of
trust, and, at some delegation point, signed proof of the trust, and, at some delegation point, signed proof of the
skipping to change at page 20, line 50 skipping to change at page 21, line 50
These definitions do not change any security considerations for the These definitions do not change any security considerations for the
DNS. DNS.
12. Acknowledgements 12. Acknowledgements
The authors gratefully acknowledge all of the authors of DNS-related The authors gratefully acknowledge all of the authors of DNS-related
RFCs that proceed this one. Comments from Tony Finch, Stephane RFCs that proceed this one. Comments from Tony Finch, Stephane
Bortzmeyer, Niall O'Reilly, Colm MacCarthaigh, Ray Bellis, John Bortzmeyer, Niall O'Reilly, Colm MacCarthaigh, Ray Bellis, John
Kristoff, Robert Edmonds, Paul Wouters, Shumon Huque, Paul Ebersman, Kristoff, Robert Edmonds, Paul Wouters, Shumon Huque, Paul Ebersman,
David Lawrence, Matthijs Mekking, Casey Deccio, Bob Harold, Ed Lewis, David Lawrence, Matthijs Mekking, Casey Deccio, Bob Harold, Ed Lewis,
and many others in the DNSOP Working Group have helped shape this John Klensin, David Black, and many others in the DNSOP Working Group
document. have helped shape this document.
13. References 13. References
13.1. Normative References 13.1. Normative References
[RFC0882] Mockapetris, P., "Domain names: Concepts and facilities", [RFC0882] Mockapetris, P., "Domain names: Concepts and facilities",
RFC 882, November 1983. RFC 882, DOI 10.17487/RFC0882, November 1983,
<http://www.rfc-editor.org/info/rfc882>.
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities", [RFC1034] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, November 1987. STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
<http://www.rfc-editor.org/info/rfc1034>.
[RFC1035] Mockapetris, P., "Domain names - implementation and [RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987. specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
November 1987, <http://www.rfc-editor.org/info/rfc1035>.
[RFC1123] Braden, R., "Requirements for Internet Hosts - Application
and Support", STD 3, RFC 1123, October 1989.
[RFC1206] Malkin, G. and A. Marine, "FYI on Questions and Answers: [RFC1123] Braden, R., Ed., "Requirements for Internet Hosts -
Answers to commonly asked "new Internet user" questions", Application and Support", STD 3, RFC 1123, DOI 10.17487/
RFC 1206, February 1991. RFC1123, October 1989,
<http://www.rfc-editor.org/info/rfc1123>.
[RFC1996] Vixie, P., "A Mechanism for Prompt Notification of Zone [RFC1996] Vixie, P., "A Mechanism for Prompt Notification of Zone
Changes (DNS NOTIFY)", RFC 1996, August 1996. Changes (DNS NOTIFY)", RFC 1996, DOI 10.17487/RFC1996,
August 1996, <http://www.rfc-editor.org/info/rfc1996>.
[RFC2136] Vixie, P., Thomson, S., Rekhter, Y., and J. Bound, [RFC2136] Vixie, P., Ed., Thomson, S., Rekhter, Y., and J. Bound,
"Dynamic Updates in the Domain Name System (DNS UPDATE)", "Dynamic Updates in the Domain Name System (DNS UPDATE)",
RFC 2136, April 1997. RFC 2136, DOI 10.17487/RFC2136, April 1997,
<http://www.rfc-editor.org/info/rfc2136>.
[RFC2181] Elz, R. and R. Bush, "Clarifications to the DNS [RFC2181] Elz, R. and R. Bush, "Clarifications to the DNS
Specification", RFC 2181, July 1997. Specification", RFC 2181, DOI 10.17487/RFC2181, July 1997,
<http://www.rfc-editor.org/info/rfc2181>.
[RFC2182] Elz, R., Bush, R., Bradner, S., and M. Patton, "Selection [RFC2182] Elz, R., Bush, R., Bradner, S., and M. Patton, "Selection
and Operation of Secondary DNS Servers", BCP 16, RFC 2182, and Operation of Secondary DNS Servers", BCP 16, RFC 2182,
July 1997. DOI 10.17487/RFC2182, July 1997,
<http://www.rfc-editor.org/info/rfc2182>.
[RFC2308] Andrews, M., "Negative Caching of DNS Queries (DNS [RFC2308] Andrews, M., "Negative Caching of DNS Queries (DNS
NCACHE)", RFC 2308, March 1998. NCACHE)", RFC 2308, DOI 10.17487/RFC2308, March 1998,
<http://www.rfc-editor.org/info/rfc2308>.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S. [RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements", RFC Rose, "DNS Security Introduction and Requirements", RFC
4033, March 2005. 4033, DOI 10.17487/RFC4033, March 2005,
<http://www.rfc-editor.org/info/rfc4033>.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S. [RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions", Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, March 2005. RFC 4034, DOI 10.17487/RFC4034, March 2005,
<http://www.rfc-editor.org/info/rfc4034>.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S. [RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, March 2005. Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
<http://www.rfc-editor.org/info/rfc4035>.
[RFC4592] Lewis, E., "The Role of Wildcards in the Domain Name [RFC4592] Lewis, E., "The Role of Wildcards in the Domain Name
System", RFC 4592, July 2006. System", RFC 4592, DOI 10.17487/RFC4592, July 2006,
<http://www.rfc-editor.org/info/rfc4592>.
[RFC5155] Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS [RFC5155] Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS
Security (DNSSEC) Hashed Authenticated Denial of Security (DNSSEC) Hashed Authenticated Denial of
Existence", RFC 5155, March 2008. Existence", RFC 5155, DOI 10.17487/RFC5155, March 2008,
<http://www.rfc-editor.org/info/rfc5155>.
[RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)", [RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
STD 69, RFC 5730, August 2009. STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
<http://www.rfc-editor.org/info/rfc5730>.
[RFC5936] Lewis, E. and A. Hoenes, "DNS Zone Transfer Protocol [RFC5936] Lewis, E. and A. Hoenes, Ed., "DNS Zone Transfer Protocol
(AXFR)", RFC 5936, June 2010. (AXFR)", RFC 5936, DOI 10.17487/RFC5936, June 2010,
<http://www.rfc-editor.org/info/rfc5936>.
[RFC6561] Livingood, J., Mody, N., and M. O'Reirdan, [RFC6561] Livingood, J., Mody, N., and M. O'Reirdan,
"Recommendations for the Remediation of Bots in ISP "Recommendations for the Remediation of Bots in ISP
Networks", RFC 6561, March 2012. Networks", RFC 6561, DOI 10.17487/RFC6561, March 2012,
<http://www.rfc-editor.org/info/rfc6561>.
[RFC6672] Rose, S. and W. Wijngaards, "DNAME Redirection in the [RFC6672] Rose, S. and W. Wijngaards, "DNAME Redirection in the
DNS", RFC 6672, June 2012. DNS", RFC 6672, DOI 10.17487/RFC6672, June 2012,
<http://www.rfc-editor.org/info/rfc6672>.
[RFC6781] Kolkman, O., Mekking, W., and R. Gieben, "DNSSEC [RFC6781] Kolkman, O., Mekking, W., and R. Gieben, "DNSSEC
Operational Practices, Version 2", RFC 6781, December Operational Practices, Version 2", RFC 6781, DOI 10.17487/
2012. RFC6781, December 2012,
<http://www.rfc-editor.org/info/rfc6781>.
[RFC6840] Weiler, S. and D. Blacka, "Clarifications and [RFC6840] Weiler, S., Ed. and D. Blacka, Ed., "Clarifications and
Implementation Notes for DNS Security (DNSSEC)", RFC 6840, Implementation Notes for DNS Security (DNSSEC)", RFC 6840,
February 2013. DOI 10.17487/RFC6840, February 2013,
<http://www.rfc-editor.org/info/rfc6840>.
[RFC6841] Ljunggren, F., Eklund Lowinder, AM., and T. Okubo, "A [RFC6841] Ljunggren, F., Eklund Lowinder, AM., and T. Okubo, "A
Framework for DNSSEC Policies and DNSSEC Practice Framework for DNSSEC Policies and DNSSEC Practice
Statements", RFC 6841, January 2013. Statements", RFC 6841, DOI 10.17487/RFC6841, January 2013,
<http://www.rfc-editor.org/info/rfc6841>.
[RFC6891] Damas, J., Graff, M., and P. Vixie, "Extension Mechanisms [RFC6891] Damas, J., Graff, M., and P. Vixie, "Extension Mechanisms
for DNS (EDNS(0))", STD 75, RFC 6891, April 2013. for DNS (EDNS(0))", STD 75, RFC 6891, DOI 10.17487/
RFC6891, April 2013,
<http://www.rfc-editor.org/info/rfc6891>.
[RFC7344] Kumari, W., Gudmundsson, O., and G. Barwood, "Automating [RFC7344] Kumari, W., Gudmundsson, O., and G. Barwood, "Automating
DNSSEC Delegation Trust Maintenance", RFC 7344, September DNSSEC Delegation Trust Maintenance", RFC 7344, DOI
2014. 10.17487/RFC7344, September 2014,
<http://www.rfc-editor.org/info/rfc7344>.
13.2. Informative References 13.2. Informative References
[DBOUND] "DBOUND Working Group", 2015, [DBOUND] "DBOUND Working Group", 2015,
<https://datatracker.ietf.org/wg/dbound/charter/>. <https://datatracker.ietf.org/wg/dbound/charter/>.
[RFC0819] Su, Z. and J. Postel, "Domain naming convention for
Internet user applications", RFC 819, DOI 10.17487/
RFC0819, August 1982,
<http://www.rfc-editor.org/info/rfc819>.
[RFC0952] Harrenstien, K., Stahl, M., and E. Feinler, "DoD Internet [RFC0952] Harrenstien, K., Stahl, M., and E. Feinler, "DoD Internet
host table specification", RFC 952, October 1985. host table specification", RFC 952, DOI 10.17487/RFC0952,
October 1985, <http://www.rfc-editor.org/info/rfc952>.
[RFC1995] Ohta, M., "Incremental Zone Transfer in DNS", RFC 1995, [RFC1995] Ohta, M., "Incremental Zone Transfer in DNS", RFC 1995,
August 1996. DOI 10.17487/RFC1995, August 1996,
<http://www.rfc-editor.org/info/rfc1995>.
[RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912, [RFC3912] Daigle, L., "WHOIS Protocol Specification", RFC 3912, DOI
September 2004. 10.17487/RFC3912, September 2004,
<http://www.rfc-editor.org/info/rfc3912>.
[RFC4641] Kolkman, O. and R. Gieben, "DNSSEC Operational Practices", [RFC4641] Kolkman, O. and R. Gieben, "DNSSEC Operational Practices",
RFC 4641, September 2006. RFC 4641, DOI 10.17487/RFC4641, September 2006,
<http://www.rfc-editor.org/info/rfc4641>.
[RFC4697] Larson, M. and P. Barber, "Observed DNS Resolution [RFC4697] Larson, M. and P. Barber, "Observed DNS Resolution
Misbehavior", BCP 123, RFC 4697, October 2006. Misbehavior", BCP 123, RFC 4697, DOI 10.17487/RFC4697,
October 2006, <http://www.rfc-editor.org/info/rfc4697>.
[RFC4786] Abley, J. and K. Lindqvist, "Operation of Anycast [RFC4786] Abley, J. and K. Lindqvist, "Operation of Anycast
Services", BCP 126, RFC 4786, December 2006. Services", BCP 126, RFC 4786, DOI 10.17487/RFC4786,
December 2006, <http://www.rfc-editor.org/info/rfc4786>.
[RFC4956] Arends, R., Kosters, M., and D. Blacka, "DNS Security [RFC4956] Arends, R., Kosters, M., and D. Blacka, "DNS Security
(DNSSEC) Opt-In", RFC 4956, July 2007. (DNSSEC) Opt-In", RFC 4956, DOI 10.17487/RFC4956, July
2007, <http://www.rfc-editor.org/info/rfc4956>.
[RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines", BCP [RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines", BCP
152, RFC 5625, August 2009. 152, RFC 5625, DOI 10.17487/RFC5625, August 2009,
<http://www.rfc-editor.org/info/rfc5625>.
[RFC5890] Klensin, J., "Internationalized Domain Names for [RFC5890] Klensin, J., "Internationalized Domain Names for
Applications (IDNA): Definitions and Document Framework", Applications (IDNA): Definitions and Document Framework",
RFC 5890, August 2010. RFC 5890, DOI 10.17487/RFC5890, August 2010,
<http://www.rfc-editor.org/info/rfc5890>.
[RFC5891] Klensin, J., "Internationalized Domain Names in [RFC5891] Klensin, J., "Internationalized Domain Names in
Applications (IDNA): Protocol", RFC 5891, August 2010. Applications (IDNA): Protocol", RFC 5891, DOI 10.17487/
RFC5891, August 2010,
<http://www.rfc-editor.org/info/rfc5891>.
[RFC5892] Faltstrom, P., "The Unicode Code Points and [RFC5892] Faltstrom, P., Ed., "The Unicode Code Points and
Internationalized Domain Names for Applications (IDNA)", Internationalized Domain Names for Applications (IDNA)",
RFC 5892, August 2010. RFC 5892, DOI 10.17487/RFC5892, August 2010,
<http://www.rfc-editor.org/info/rfc5892>.
[RFC5893] Alvestrand, H. and C. Karp, "Right-to-Left Scripts for [RFC5893] Alvestrand, H., Ed. and C. Karp, "Right-to-Left Scripts
Internationalized Domain Names for Applications (IDNA)", for Internationalized Domain Names for Applications
RFC 5893, August 2010. (IDNA)", RFC 5893, DOI 10.17487/RFC5893, August 2010,
<http://www.rfc-editor.org/info/rfc5893>.
[RFC5894] Klensin, J., "Internationalized Domain Names for [RFC5894] Klensin, J., "Internationalized Domain Names for
Applications (IDNA): Background, Explanation, and Applications (IDNA): Background, Explanation, and
Rationale", RFC 5894, August 2010. Rationale", RFC 5894, DOI 10.17487/RFC5894, August 2010,
<http://www.rfc-editor.org/info/rfc5894>.
[RFC6055] Thaler, D., Klensin, J., and S. Cheshire, "IAB Thoughts on
Encodings for Internationalized Domain Names", RFC 6055,
DOI 10.17487/RFC6055, February 2011,
<http://www.rfc-editor.org/info/rfc6055>.
[RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265, [RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265,
April 2011. DOI 10.17487/RFC6265, April 2011,
<http://www.rfc-editor.org/info/rfc6265>.
[RFC6365] Hoffman, P. and J. Klensin, "Terminology Used in
Internationalization in the IETF", BCP 166, RFC 6365, DOI
10.17487/RFC6365, September 2011,
<http://www.rfc-editor.org/info/rfc6365>.
[RFC7129] Gieben, R. and W. Mekking, "Authenticated Denial of [RFC7129] Gieben, R. and W. Mekking, "Authenticated Denial of
Existence in the DNS", RFC 7129, February 2014. Existence in the DNS", RFC 7129, DOI 10.17487/RFC7129,
February 2014, <http://www.rfc-editor.org/info/rfc7129>.
[RFC7480] Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
Registration Data Access Protocol (RDAP)", RFC 7480, DOI
10.17487/RFC7480, March 2015,
<http://www.rfc-editor.org/info/rfc7480>.
[RFC7481] Hollenbeck, S. and N. Kong, "Security Services for the
Registration Data Access Protocol (RDAP)", RFC 7481, DOI
10.17487/RFC7481, March 2015,
<http://www.rfc-editor.org/info/rfc7481>.
[RFC7482] Newton, A. and S. Hollenbeck, "Registration Data Access
Protocol (RDAP) Query Format", RFC 7482, DOI 10.17487/
RFC7482, March 2015,
<http://www.rfc-editor.org/info/rfc7482>.
[RFC7483] Newton, A. and S. Hollenbeck, "JSON Responses for the
Registration Data Access Protocol (RDAP)", RFC 7483, DOI
10.17487/RFC7483, March 2015,
<http://www.rfc-editor.org/info/rfc7483>.
[RFC7484] Blanchet, M., "Finding the Authoritative Registration Data
(RDAP) Service", RFC 7484, DOI 10.17487/RFC7484, March
2015, <http://www.rfc-editor.org/info/rfc7484>.
[RFC7485] Zhou, L., Kong, N., Shen, S., Sheng, S., and A. Servin,
"Inventory and Analysis of WHOIS Registration Objects",
RFC 7485, DOI 10.17487/RFC7485, March 2015,
<http://www.rfc-editor.org/info/rfc7485>.
Authors' Addresses Authors' Addresses
Paul Hoffman Paul Hoffman
VPN Consortium ICANN
127 Segre Place
Santa Cruz, CA 95060
USA
Email: paul.hoffman@vpnc.org Email: paul.hoffman@icann.org
Andrew Sullivan Andrew Sullivan
Dyn Dyn
150 Dow St, Tower 2 150 Dow St, Tower 2
Manchester, NH 1604 Manchester, NH 1604
USA USA
Email: asullivan@dyn.com Email: asullivan@dyn.com
Kazunori Fujiwara Kazunori Fujiwara
Japan Registry Services Co., Ltd. Japan Registry Services Co., Ltd.
Chiyoda First Bldg. East 13F, 3-8-1 Nishi-Kanda Chiyoda First Bldg. East 13F, 3-8-1 Nishi-Kanda
Chiyoda-ku, Tokyo 101-0065 Chiyoda-ku, Tokyo 101-0065
Japan Japan
Phone: +81 3 5215 8451 Phone: +81 3 5215 8451
Email: fujiwara@jprs.co.jp Email: fujiwara@jprs.co.jp
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