Extensible Delegation for DNS
draft-homburg-deleg-01
This document is an Internet-Draft (I-D).
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Philip Homburg , Tim Wicinski , Jesse van Zutphen , Willem Toorop | ||
| Last updated | 2025-04-03 | ||
| Replaces | draft-homburg-deleg-incremental-deleg | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-homburg-deleg-01
DNS Delegation P. Homburg
Internet-Draft NLnet Labs
Intended status: Standards Track T. Wicinski
Expires: 5 October 2025 Cox Communications
J. V. Zutphen
University of Amsterdam
W. Toorop
NLnet Labs
3 April 2025
Extensible Delegation for DNS
draft-homburg-deleg-01
Abstract
This document proposes a mechanism for extensible delegations in the
DNS. The mechanism realizes delegations with resource record sets
placed below a _deleg label in the apex of the delegating zone. This
authoritative delegation point can be aliased to other names using
CNAME and DNAME. This document proposes a new DNS resource record
type, IDELEG, which is based on the SVCB and inherits extensibility
from it.
IDELEG RRsets containing delegation information will be returned in
the authority section in referral responses from supportive
authoritative name servers. Lack of support in the authoritative
name servers, forwarders or other components, does not obstruct
obtaining the delegation information for resolvers, as it is
originally authoritative information that can be queried for
directly. None, mixed or full deployment of the mechanism on
authoritative name servers are all fully functional, allowing for the
mechanism to be incrementally deployed on the authoritative name
servers.
About This Document
This note is to be removed before publishing as an RFC.
Status information for this document may be found at
https://datatracker.ietf.org/doc/draft-homburg-deleg/.
Discussion of this document takes place on the deleg Working Group
mailing list (mailto:dd@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/dd/. Subscribe at
https://www.ietf.org/mailman/listinfo/dd/.
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Source for this draft and an issue tracker can be found at
https://github.com/NLnetLabs/incremental-deleg.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on 5 October 2025.
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Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Signaling capabilities of the authoritative name
servers . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. _Note to the RFC Editor_: please remove this subsection
before publication. . . . . . . . . . . . . . . . . . . . 4
1.3. Outsourcing operation of the delegation . . . . . . . . . 4
1.4. DNSSEC protection of the delegation . . . . . . . . . . . 4
1.5. Maximize ease of deployment . . . . . . . . . . . . . . . 5
1.6. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
2. The IDELEG resource record type . . . . . . . . . . . . . . . 6
3. Delegation administration . . . . . . . . . . . . . . . . . . 7
3.1. Examples . . . . . . . . . . . . . . . . . . . . . . . . 8
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3.1.1. One name server within the subzone . . . . . . . . . 8
3.1.2. Two name servers within the subzone . . . . . . . . . 8
3.1.3. Outsourced to an operator . . . . . . . . . . . . . . 8
3.1.4. DNSSEC-signed name servers within the subzone . . . . 9
4. Authoritative name server support . . . . . . . . . . . . . . 11
4.1. Registration of authoritative name server support . . . . 15
4.2. Support detection with unsigned zones . . . . . . . . . . 15
4.3. Deregistering authoritative name server support . . . . . 16
5. Resolving without authoritative name server support . . . . . 16
5.1. The deleg query . . . . . . . . . . . . . . . . . . . . . 17
5.2. _deleg label presence . . . . . . . . . . . . . . . . . . 19
5.2.1. Test _deleg label presence (unsigned zones only) . . 19
5.3. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.3.1. Reduced latency . . . . . . . . . . . . . . . . . . . 21
6. Priming queries . . . . . . . . . . . . . . . . . . . . . . . 22
7. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . 22
8. How does the protocol described in this draft meet the
requirements . . . . . . . . . . . . . . . . . . . . . . 22
9. Implementation Status . . . . . . . . . . . . . . . . . . . . 24
10. Security Considerations . . . . . . . . . . . . . . . . . . . 25
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
11.1. IDELEG RR type . . . . . . . . . . . . . . . . . . . . . 25
11.2. _deleg Node Name . . . . . . . . . . . . . . . . . . . . 26
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 26
12.1. Normative References . . . . . . . . . . . . . . . . . . 26
12.2. Informative References . . . . . . . . . . . . . . . . . 27
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29
1. Introduction
This document describes a delegation mechanism for the Domain Name
System (DNS) [STD13] that addresses several matters that, at the time
of writing, are suboptimally supported or not supported at all.
These matters are elaborated upon in sections 1.1, 1.3 and 1.4. In
addition, the mechanism described in this document aspires to be
maximally deployable, which is elaborated upon in Section 1.5.
1.1. Signaling capabilities of the authoritative name servers
A new IDELEG resource record (RR) type is introduced in this
document, which is based on and inherits the wire and presentation
format from SVCB [RFC9460]. All Service Binding Mappings, as well as
the capability signalling, that are specified in [RFC9461] are also
applicable to IDELEG, with the exception of the limitations on
AliasMode records in Section 6 of [RFC9460]. Capability signalling
of DNS over Transport Layer Protocol [RFC7858] (DoT), DNS Queries
over HTTPS [RFC8484] and DNS over Dedicated QUIC Connections
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[RFC9250], on default or alternative ports, can all be used as
specified in [RFC9461]. The IDELEG RR type inherits its
extensibility from the SVCB RR type, which is designed to be
extensible to support future uses (such as keys for encrypting the
TLS ClientHello [I-D.ietf-tls-esni].)
1.2. _Note to the RFC Editor_: please remove this subsection before
publication.
The name IDELEG is chosen to avoid confusion with
[I-D.wesplaap-deleg].
1.3. Outsourcing operation of the delegation
Delegation information is stored at an authoritative location in the
zone with this mechanism. Legacy methods to redirect this
information to another location, possible under the control of
another operator, such as (CNAME Section 3.6.2 of [RFC1034]) and
DNAME [RFC6672] remain functional. One could even outsource all
delegation operational practice to another party with a DNAME record
on the _deleg label on the apex of the delegating zone.
Additional to the legacy methods, a delegation may be outsourced to a
set of third parties by having RRs in AliasMode. Unlike SVCB, IDELEG
allows for more than a single IDELEG RR in AliasMode in an IDELEG
RRset, enabling outsourcing a delegation to multiple different
operators.
1.4. DNSSEC protection of the delegation
With legacy delegations, the NS RRset at the parent side of a
delegation as well as glue records for the names in the NS RRset are
not authoritative and not DNSSEC signed. An adversary that is able
to spoof a referral response, can alter this information and redirect
all traffic for the delegation to a rogue name server undetected.
The adversary can then perceive all queries for the redirected zone
(Privacy concern) and alter all unsigned parts of responses (such as
further referrals, which is a Security concern).
DNSSEC protection of delegation information prevents that, and is the
only countermeasure that also works against on-path attackers. At
the time of writing, the only way to DNSSEC-validate and verify
delegations at all levels in the DNS hierarchy is to revalidate
delegations [I-D.ietf-dnsop-ns-revalidation], which is done after the
fact and has other security concerns (Section 7 of
[I-D.ietf-dnsop-ns-revalidation]).
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Direct delegation information (provided by IDELEG RRs in ServiceMode)
includes the hostnames of the authoritative name servers for the
delegation as well as IP addresses for those hostnames. Since the
information is stored authoritatively in the delegating zone, it will
be DNSSEC-signed if the zone is signed. When the delegation is
outsourced, then it's protected when the zones providing the aliasing
resource records _and_ the zones serving the targets of the aliases
are all DNSSEC-signed.
1.5. Maximize ease of deployment
Delegation information is stored authoritatively within the
delegating zone. No semantic changes as to what zones are
authoritative for what data are needed. As a consequence, existing
DNS software, such as authoritative name servers and DNSSEC signing
software, can remain unmodified. Unmodified authoritative name
server software will serve the delegation information when queried
for. Unmodified signers will sign the delegation information in the
delegating zone. Support for IDELEG is only required for
functionalities following delegations (like recursive resolvers), but
they do not need of the components it queries. None, mixed or full
deployment of the mechanism on authoritative name servers are all
fully functional, allowing for the mechanism to be incrementally
deployed on the authoritative name servers.
1.6. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
This document follows terminology as defined in [BCP219].
Throughout this document we will also use terminology with the
meaning as defined below:
Deleg:
The delegation mechanism as specified in this document.
IDELEG delegation:
A delegation as specified in this document
Legacy delegations:
The way delegations are done in the DNS traditionally as defined
in [STD13].
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Delegating zone:
The zone in which the delegation is administered. Sometimes also
called the "parent zone" of a delegation.
Subzone:
The zone that is delegated to from the delegating zone.
Delegating name:
The name which realizes the delegation. In legacy delegations,
this name is the same as the name of the subzone to which the
delegation refers. Delegations described in this document are
provided with a different name than the zone that is delegated to.
If needed we differentiate by explicitly calling it IDELEG
delegation name or legacy delegation name.
Deleg query:
An explicit query for IDELEG RRset at the delegating name as used
for IDELEG delegations.
Delegation point:
The location in the delegating zone where the RRs are provided
that make up the delegation. In legacy delegations, this is the
parent side of the zone cut and has the same name as the subzone.
With deleg, this is the location given by the IDELEG delegating
name. If needed we differentiate by explicitly calling it IDELEG
delegation point or legacy delegation point.
Triggering query:
The query on which resolution a recursive resolver is working.
Target zone:
The zone for which the authoritative servers, that a resolver
contacts while iterating, are authoritative.
2. The IDELEG resource record type
The IDELEG RR type is a variant of SVCB [RFC9460] for use with
resolvers to perform iterative resolution (Section 5.3.3 of
[RFC1034]). The IDELEG type requires registration in the "Resource
Record (RR) TYPEs" registry under the "Domain Name System (DNS)
Parameters" registry group (see IDELEG RR type (Section 11.1)). The
protocol-specific mapping specification for iterative resolutions are
the same as those for "DNS Servers" [RFC9461].
Section 2.4.2 of [RFC9460] states that SVCB RRsets SHOULD only have a
single RR in AliasMode, and that if multiple AliasMode RRs are
present, clients or recursive resolvers SHOULD pick one at random.
Different from SVCB (Section 2.4.2 of [RFC9460]), IDELEG allows for
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multiple AliasMode RRs to be present in a single IDELEG RRset. Note
however that the target of an IDELEG RR in AliasMode is an SVCB RRset
for the "dns" service type adhering fully to the Service Binding
Mapping for DNS Servers as specified in [RFC9461].
Section 2.4.1 of [RFC9460] states that within an SVCB RRset, all RRs
SHOULD have the same mode, and that if an RRset contains a record in
AliasMode, the recipient MUST ignore any ServiceMode records in the
set. Different from SVCB, mixed ServiceMode and AliasMode RRs are
allowed in an IDELEG RRset. When a mixed ServiceMode and AliasMode
IDELEG RRset is encountered by a resolver, the resolver first picks
one of the AliasMode RRs or all ServiceMode RRs, giving all
ServiceMode RRs equal weight as each single AliasMode RR. When the
result of that choice is an AliasMode RR, then that RR is followed
and the resulting IDELEG RRset is reevaluated. When the result of
that choice is all ServiceMode RRs, then within that set the resolver
adheres to the ServicePriority value.
At the delegation point (for example customer._deleg.example.), the
host names of the authoritative name servers for the subzone, are
given in the TargetName RDATA field of IDELEG records in ServiceMode.
Port Prefix Naming Section 3 of [RFC9461] is not used at the
delegation point, but MUST be used when resolving the aliased-to name
servers with IDELEG RRs in AliasMode.
3. Delegation administration
An IDELEG delegation is realized with an IDELEG Resource Record set
(RRset) [RFC9460] below a specially for the purpose reserved label
with the name _deleg at the apex of the delegating zone. The _deleg
label scopes the interpretation of the IDELEG records and requires
registration in the "Underscored and Globally Scoped DNS Node Names"
registry (see _deleg Node Name (Section 11.2)). The full scoping of
delegations includes the labels that are *below* the _deleg label and
those, together with the name of the delegating domain, make up the
name of the subzone to which the delegation refers. For example, if
the delegating zone is example., then a delegation to subzone
customer.example. is realized by a IDELEG RRset at the name
customer._deleg.example. in the parent zone. A fully scoped
delegating name (such as customer._deleg.example.) is referred to
further in this document as the "delegation point".
Note that if the delegation is outsourcing to a single operator
represented in a single IDELEG RR, it is RECOMMENDED to refer to the
name of the operator's IDELEG RRset with a CNAME on the delegation
point instead of a IDELEG RR in AliasMode Section 10.2 of [RFC9460].
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For reasons that will be explained in Section 4.2, operators SHOULD
include the following in zones that include IDELEG records: *._deleg
86400 IN IDELEG 0 .
3.1. Examples
3.1.1. One name server within the subzone
$ORIGIN example.
@ IN SOA ns zonemaster ...
customer1._deleg IN IDELEG 1 ( ns.customer1
ipv4hint=198.51.100.1,203.0.113.1
ipv6hint=2001:db8:1::1,2001:db8:2::1
)
Figure 1: One name server within the subzone
3.1.2. Two name servers within the subzone
$ORIGIN example.
@ IN SOA ns zonemaster ...
customer2._deleg IN IDELEG 1 ns1.customer2 ( ipv4hint=198.51.100.1
ipv6hint=2001:db8:1::1
)
IN IDELEG 1 ns2.customer2 ( ipv4hint=203.0.113.1
ipv6hint=2001:db8:2::1
)
Figure 2: Two name servers within the subzone
3.1.3. Outsourced to an operator
$ORIGIN example.
@ IN SOA ns zonemaster ...
customer3._deleg IN CNAME _dns.ns.operator1
Figure 3: Outsourced with CNAME
Instead of using CNAME, the outsourcing could also have been
accomplished with an IDELEG RRset with a single IDELEG RR in
AliasMode. The configuration below is operationally equivalent to
the CNAME configuration above. It is RECOMMENDED to use a CNAME over
an IDELEG RRset with a single IDELEG RR in AliasMode (Section 10.2 of
[RFC9460]). Note that an IDELEG RRset refers with TargetName to a
DNS service [RFC9461], which will be looked up using Port Prefix
Naming Section 3 of [RFC9461], but that an CNAME refers to the domain
name of the target SVCB RRset instead (or CNAME) which may have a
_dns prefix.
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$ORIGIN example.
@ IN SOA ns zonemaster ...
customer3._deleg IN IDELEG 0 ns.operator1
Figure 4: Outsourced with an AliasMode IDELEG RR
The operator SVCB RRset could for example be:
$ORIGIN operator1.example.
@ IN SOA ns zonemaster ...
_dns.ns IN SVCB 1 ns ( alpn=h2,dot,h3,doq
ipv4hint=192.0.2.1
ipv6hint=2001:db8:3::1
dohpath=/q{?dns}
)
IN SVCB 2 ns ( ipv4hint=192.0.2.2
ipv6hint=2001:db8:3::2
)
ns IN AAAA 2001:db8:3::1
IN AAAA 2001:db8:3::2
IN A 192.0.2.1
IN A 192.0.2.2
Figure 5: Operator zone
3.1.4. DNSSEC-signed name servers within the subzone
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$ORIGIN
@ IN SOA ns zonemaster ...
IN RRSIG SOA ...
IN DNSKEY 257 3 15 ...
IN RRSIG DNSKEY ...
IN NS ns.example.
IN RRSIG NS ...
IN NSEC customer5._deleg NS SOA RRSIG NSEC DNSKEY
IN RRSIG NSEC ...
customer5._deleg IN IDELEG 1 ns.customer5 alpn=h2,h3 (
ipv4hint=198.51.100.5
ipv6hint=2001:db8:5::1
dohpath=/dns-query{?dns}
)
IN RRSIG IDELEG ...
IN NSEC customer7._deleg RRSIG NSEC IDELEG
IN RRSIG NSEC ...
customer7._deleg IN CNAME customer5._deleg
IN RRSIG CNAME ...
IN NSEC customer5 CNAME RRSIG NSEC
IN RRSIG NSEC ...
customer5 IN NS ns.customer5
ns.customer5 IN A 198.51.100.5
IN AAAA 2001:db8:5::1
customer5 IN DS 17405 15 2 ...
IN RRSIG DS ...
IN NSEC customer6 NS DS RRSIG NSEC
IN RRSIG NSEC ...
customer6 IN NS ns.customer6
ns.customer6 IN A 203.0.113.1
IN AAAA 2001:db8:6::1
customer6 IN DS ...
IN RRSIG DS ...
IN NSEC customer7 NS DS RRSIG NSEC
IN RRSIG NSEC ...
customer7 IN NS ns.customer5
IN DS ...
IN RRSIG DS ...
IN NSEC example. NS DS RRSIG NSEC
IN RRSIG NSEC ...
Figure 6: DNSSEC-signed deleg zone
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customer5.example. is delegated to in an extensible way and
customer6.example. is delegated only in a legacy way.
customer7.example.'s delegation is outsourced to customer5's
delegation.
The delegation signals that the authoritative name server supports
DoH. customer5.example., customer6.example. and example. are all
DNSSEC-signed. The DNSSEC authentication chain links from example.
to customer5.example. in the for DNSSEC conventional way with the
signed customer5.example. DS RRset in the example. zone. Also,
customer6.example. is linked to from example. with the signed
customer6.example. DS RRset in the example. zone.
Note that both customer5.example. and customer6.example. have legacy
delegations in the zone as well. It is important to have those
legacy delegations to maintain support for legacy resolvers, that do
not support deleg. DNSSEC signers SHOULD construct the NS RRset and
glue for the legacy delegation from the IDELEG RRset.
4. Authoritative name server support
Deleg supporting authoritative name servers include the IDELEG
delegation information (or the NSEC(3) records showing the non-
existence) in the authority section of referral responses to legacy
DNS queries. For example, querying the zone from Figure 6 for
www.customer5.example. A, will return the following referral
response:
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;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 54349
;; flags: qr ; QUERY: 1, ANSWER: 0, AUTHORITY: 5, ADDITIONAL: 2
;; QUESTION SECTION:
;; www.customer5.example. IN A
;; ANSWER SECTION:
;; AUTHORITY SECTION:
customer5.example. 3600 IN NS ns.customer5.example.
customer5.example. 3600 IN DS ...
customer5.example. 3600 IN RRSIG DS ...
customer5._deleg.example. 3600 IN IDELEG 1 (
ns.customer5.example. alpn=h2,h3
ipv4hint=198.51.100.5 ipv6hint=2001:db8:5::1
dohpath=/dns-query{?dns}
)
customer5._deleg.example. 3600 IN RRSIG IDELEG ...
;; ADDITIONAL SECTION:
ns.customer5.example. 3600 IN A 198.51.100.5
ns.customer5.example. 3600 IN AAAA 2001:db8:5::1
;; Query time: 0 msec
;; EDNS: version 0; flags: do ; udp: 1232
;; SERVER: 192.0.2.53
;; WHEN: Mon Feb 24 20:36:25 2025
;; MSG SIZE rcvd: 456
Figure 7: A deleg referral response
The referral response in Figure 7 includes the signed IDELEG RRset in
the authority section.
As another example, querying the zone from Figure 6 for
www.customer6.example. A, will return the following referral
response:
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;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 36574
;; flags: qr ; QUERY: 1, ANSWER: 0, AUTHORITY: 9, ADDITIONAL: 2
;; QUESTION SECTION:
;; www.customer6.example. IN A
;; ANSWER SECTION:
;; AUTHORITY SECTION:
customer6.example. 3600 IN NS ns.customer6.example.
customer6.example. 3600 IN DS ...
customer6.example. 3600 IN RRSIG DS ...
customer5._deleg.example. 1234 IN NSEC (
customer7._deleg.example. RRSIG NSEC IDELEG )
customer5._deleg.example. 1234 IN RRSIG NSEC ...
example. 1234 IN NSEC (
customer5._deleg.example. NS SOA RRSIG NSEC DNSKEY )
example. 1234 IN RRSIG NSEC ...
;; ADDITIONAL SECTION:
ns.customer6.example. 3600 IN A 203.0.113.1
ns.customer6.example. 3600 IN AAAA 2001:db8:6::1
;; Query time: 0 msec
;; EDNS: version 0; flags: do ; udp: 1232
;; SERVER: 192.0.2.53
;; WHEN: Tue Feb 25 10:23:53 2025
;; MSG SIZE rcvd: 744
Figure 8: Referral response without deleg
Next to the legacy delegation, the deleg supporting authoritative
returns the NSEC(3) RRs needed to show that there was no IDELEG
delegation in the referral response in Figure 8.
Querying the zone from Figure 6 for www.customer7.example. A, will
return the following referral response:
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;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 9456
;; flags: qr ; QUERY: 1, ANSWER: 0, AUTHORITY: 7, ADDITIONAL: 2
;; QUESTION SECTION:
;; www.customer7.example. IN A
;; ANSWER SECTION:
;; AUTHORITY SECTION:
customer7.example. 3600 IN NS ns.customer5.example.
customer7.example. 3600 IN DS ...
customer7.example. 3600 IN RRSIG DS ...
customer7._deleg.example. 3600 IN CNAME (
customer5._deleg.example. )
customer7._deleg.example. 3600 IN RRSIG CNAME ...
customer5._deleg.example. 3600 IN IDELEG 1 (
ns.customer5.example. alpn=h2,h3
ipv4hint=198.51.100.5 ipv6hint=2001:db8:5::1 )
customer5._deleg.example. 3600 IN RRSIG IDELEG ...
;; ADDITIONAL SECTION:
ns.customer5.example. 3600 IN A 198.51.100.5
ns.customer5.example. 3600 IN AAAA 2001:db8:5::1
;; Query time: 0 msec
;; EDNS: version 0; flags: do ; udp: 1232
;; SERVER: 192.0.2.53
;; WHEN: Tue Feb 25 10:55:07 2025
;; MSG SIZE rcvd: 593
Figure 9: Aliasing referral response
The delegation of customer7.example. is aliased to the one that is
also used by customer5.example. Since both delegations are in the
same zone, the authoritative name server for example. returns both
the CNAME realising the alias, as well as the IDELEG RRset which is
the target of the alias in Figure 9. In other cases a returned CNAME
or IDELEG RR in AliasMode may need further chasing by the resolver.
With unsigned zones, only if an IDELEG delegation exists, the IDELEG
RRset (or CNAME) will be present in the authority section of referral
responses. If there is no IDELEG delegation, then the IDELEG RRset
(or CNAME) is simply absent from the authority section and the
referral response is indistinguishable from an non deleg supportive
authoritative.
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4.1. Registration of authoritative name server support
When the authority section of a referral response contains an IDELEG
RRset or a CNAME record on the IDELEG delegation name, or valid
NSEC(3) RRs showing the non-existence of such an IDELEG or CNAME
RRset, then IDELEG supporting resolver SHOULD register that the
contacted authoritative name server supports deleg for the duration
indicated by the TTL for that IDELEG, CNAME or NSEC(3) RRset,
adjusted to the resolver's TTL boundaries (Section 4 of [RFC8767]),
but only if it is longer than any already registered duration.
For example, in Figure 7, the IDELEG RRset at the IDELEG delegation
point has TTL 3600. The resolver should register that the contacted
authoritative name server supports deleg for (at least) 3600 seconds
(one hour). All subsequent queries to that authoritative name server
SHOULD NOT include deleg queries to be send in parallel.
If the authority section contains more than one RRset making up the
IDELEG delegation, then the RRset with the longest TTL MUST be taken
to determine the duration for which deleg support is registered.
For example, in Figure 9, both a CNAME and an IDELEG RRset for the
IDELEG delegation are included in the authority section. The longest
TTL must be taken for deleg support registration, though because the
TTL of both RRsets is 3600, it does not matter in this case.
If an proof of non-existence of an IDELEG delegation is returned in
the authority section of a referral response, IDELEG supporting
resolvers SHOULD register that the authoritative name server that
returned that response supports IDELEG for the duration of the
maximum of the TTL of the NSEC(3) covering the name of the IDELEG
delegation and the minimum rdata field of the SOA for the zone,
adjusted to the boundaries for TTL values that the resolver has
(Section 4 of [RFC8767]), but only if it is longer than any already
registered duration.
4.2. Support detection with unsigned zones
An IDELEG RRset on an IDELEG delegation point, with an IDELEG RR in
AliasMode, aliasing to the root zone, MUST be interpreted to mean
that the legacy delegation information MUST be used to follow the
referral. All service parameters for such AliasMode (aliasing to the
root) IDELEG RRs on the IDELEG delegation point, MUST be ignored.
For example, such an IDELEG RRset registered on the wildcard below
the _deleg label on the apex of a zone, can signal that legacy DNS
referrals MUST be used for both signed and _unsigned_ zones:
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$ORIGIN example.
@ IN SOA ns zonemaster ...
*._deleg 86400 IN IDELEG 0 .
customer1._deleg IN IDELEG 1 ( ns.customer1
ipv4hint=198.51.100.1,203.0.113.1
ipv6hint=2001:db8:1::1,2001:db8:2::1
)
customer3._deleg IN CNAME _dns.ns.operator1
Figure 10: Wildcard IDELEG delegation to control duration of
detected support
Resolvers SHOULD register that an authoritative name server supports
deleg, if such an IDELEG RRset is returned in the authority section
of referral responses, for the duration of the TTL if the IDELEG
RRset, adjusted to the resolver's TTL boundaries (Section 4 of
[RFC8767]), but only if it is longer than any already registered
duration. Note that this will also be included in referral responses
for unsigned zones, which would otherwise not have signalling of
deleg support by the authoritative name server.
Also, signed zones need fewer RRs to indicate that no IDELEG
delegation exists. The wildcard expansion already shows the closest
encloser (i.e. _deleg.<apex>), so only one additional NSEC(3) is
needed to show non-existence of the queried-for name below the
closest encloser.
This method of signalling that the legacy delegation MUST be used, is
RECOMMENDED.
4.3. Deregistering authoritative name server support
If the resolver knows that the authoritative name server supports
deleg, _and_ a DNSSEC-signed zone is being served, then all referrals
SHOULD contain either an IDELEG delegation, or NSEC(3) records
showing that the delegation does not exist. If a referral is
returned that does not contain an IDELEG delegation nor an indication
that it does not exist, then the resolver MAY deregister that the
authoritative server supports IDELEG and MUST send an additional
deleg query to find the delegation (or denial of its existence) (see
also Resolving without authoritative name server support
(Section 5)).
5. Resolving without authoritative name server support
In two cases, resolvers do *not* need to do additional processing.
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1. As part of the processing a recursive resolver does, it learns
where the zone boundaries are in the DNS name tree. If the
triggering query name is already known to be the apex of a zone,
then no further delegation point probing will need to be done for
this name (subject to the TTL of this information).
2. If a resolver encounters a non-referral response, then no
delegations are involved and no further delegation probing is
needed for this name (subject to the TTL of this information).
If a resolver encounters an referral that does not contain an IDELEG
delegation nor an indication that it does not exist, then the
resolver MUST find out whether the queried zone contains IDELEG
delegations at all.
1. For DNSSEC signed zones, a direct query for the IDELEG delegation
information suffices (see The deleg query (Section 5.1)).
2. For unsigned zones, if unknown, the presence of the _deleg label
at the zone's apex needs to be detected in addition to a direct
query for the IDELEG delegation information (see _deleg label
presence (Section 5.2)).
Sub section Summary (Section 5.3) contains an overview summarizing
sub sections Section 5.1 and Section 5.2
5.1. The deleg query
The deleg query name is constructed by concatenating the first label
below the part that the triggering query name has in common with the
target zone, a _deleg label and the name of the target zone. For
example if the triggering query is www.customer.example. and the
target zone example., then the deleg query name is
customer._deleg.example. For another example, if the triggering
query is www.faculty.university.example. and the target zone
faculty.university.example. then the deleg query name is
www._deleg.faculty.university.example.
DNAME, CNAME and IDELEG in AliasMode processing happens as before,
though note that when following an IDELEG RR in AliasMode the target
RR type is SVCB (see Section 2). The eventual deleg query response,
after following all redirections caused by DNAME, CNAME and AliasMode
IDELEG RRs, has three possible outcomes:
1. An IDELEG RRset in ServiceMode is returned in the response's
answer section containing the delegation for the subzone.
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The IDELEG RRs in the RRset MUST be used to follow the referral.
The TargetName data field in the IDELEG RRs in the RRset MUST be
used as the names for the name servers to contact for the
subzone, and the ipv4hint and ipv6hint parameters MUST be used as
the IP addresses for the TargetName in the same IDELEG RR.
The NS RRset and glue, from the referral response, MUST NOT be
used, but the signed DS record (or NSEC(3) records indicating
that there was no DS) MUST be used in linking the DNSSEC
authentication chain as which would conventionally be done with
DNSSEC as well.
2. The deleg query name does not exist (NXDOMAIN).
There is no IDELEG delegation for the subzone, and the referral
response for the legacy delegation MUST be processed as would be
done with legacy DNS and DNSSEC processing.
When the query was for an DNSSEC signed zone, the NXDOMAIN
response will expose whether or not the _deleg label exists at
the zone's apex. If it does not exist, this should be registered
for the duration of the maximum of the TTL of the NSEC(3)
covering the _deleg label and the minimum rdata field of the SOA
for the zone, adjusted to the boundaries for TTL values that the
resolver has (Section 4 of [RFC8767]). For this period, deleg
queries to this zone MUST NOT be made (see also Section 5.2).
3. The deleg query name does exist, but resulted in a NOERROR no
answer response (also known as a NODATA response).
If the legacy query, did result in a referral for the same number
of labels as the subdomain that the deleg query was for, then
there was no IDELEG delegation for the subzone, and the referral
response for the legacy delegation MUST be processed as would be
done with legacy DNS and DNSSEC processing.
Otherwise, the subzone may be more than one label below the
delegating zone.
A new deleg query MUST be spawned, matching the zone cut of the
initial referral response. For example if the triggering query
is www.university.ac.example. and the target zone example., and
the legacy response contained an NS RRset for
university.ac.example., then the deleg query name is
university.ac._deleg.example. The response to the new deleg
query MUST be processed as described above, as if it was the
initial deleg query.
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If the legacy query was sent minimised and needs a followup
query, then parallel to that followup query a new deleg query
will be sent, adding a single label to the previous deleg query
name. For example if the triggering query is
www.university.ac.example. and the target zone is example. and
the minimised legacy query name is ac.example. (which also
resulted in a NOERROR no answer response), then the deleg query
to be sent along in parallel with the followup legacy query will
become university.ac._deleg.example. Processing of the responses
of those two new queries will be done as described above.
5.2. _deleg label presence
Absence of the _deleg label in a zone is a clear signal that the zone
does not contain any IDELEG delegations. Recursive resolvers SHOULD
NOT send any additional deleg queries for zones for which it is known
that it does not contain the _deleg label at the apex. The state
regarding the presence of the _deleg label within a resolver can be
"unknown", "known not to be present", or "known to be present".
The state regarding the presence of the _deleg label can be deduced
from the response of the deleg query, if the target zone is signed
with DNSSEC. *No* additional queries are needed. If the target zone
is unsigned, the procedure as described in the remainder of this
section SHOULD be followed.
5.2.1. Test _deleg label presence (unsigned zones only)
When the presence of a _deleg label is "unknown", a _deleg presence
test query SHOULD be sent in parallel to the next query for the
unsigned target zone (though not when the target name server is known
to support _deleg, which is discussed in Authoritative name server
support (Section 4)). The query name for the test query is the
_deleg label prepended to the apex of zone for which to test
presence, with query type NS.
The testing query can have three possible outcomes:
1. The _deleg label does not exist within the zone, and an NXDOMAIN
response is returned.
The non-existence of the _deleg label MUST be registered for the
duration indicated by the "minimum" RDATA field of the SOA
resource record in the authority section, adjusted to the
boundaries for TTL values that the resolver has (Section 4 of
[RFC8767]). For the period the non-existence of the _deleg label
is cached, the label is "known not to be present" and the
resolver SHOULD NOT send any (additional) deleg queries.
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2. The _deleg label does exist within the zone but contains no data.
A NOERROR response is returned with no RRs in the answer section.
The existence of the _deleg name MUST be cached for the duration
indicated by the "minimum" RDATA field of the SOA resource record
in the authority section, adjusted to the resolver's TTL
boundaries (Section 4 of [RFC8767]). For the period the
existence of the empty non-terminal at the _deleg label is
cached, the label is "known to be present".
3. The _deleg label does exist within the zone, but is a delegation.
A NOERROR legacy referral response is returned with an NS RRset
in the authority section.
The resolver MUST record that the zone does not have valid IDELEG
delegations deployed for the duration indicated by the NS RRset's
TTL value, adjusted to the resolver's TTL boundaries (Section 4
of [RFC8767]). For the period indicated by the NS RRset's TTL
value, the zone is considered to *not* to have valid IDELEG
delegations, and MUST NOT send any (additional) deleg queries.
5.3. Summary
Table Table 1 provides an overview of when additional queries,
following a non-IDELEG referral response, are sent.
+===+=========+==========+===+=====================+================+
| | auth | _deleg | | | <sub>._deleg.<apex> | _deleg.<apex> |
| | support | presence | | IDELEG | A |
+===+=========+==========+===+=====================+================+
| 1 | Yes | * | | | | |
+---+---------+----------+---+---------------------+----------------+
| 2 | No | No | | | | |
+---+---------+----------+---+---------------------+----------------+
| 3 | No | Yes | | | X | |
+---+---------+----------+---+---------------------+----------------+
| 4 | No | Unknown | | | X | only for |
| | | | | | unsigned |
| | | | | | zones |
+---+---------+----------+---+---------------------+----------------+
Table 1: Additional queries to an non-IDELEG referral response
The two headers on the left side of the table mean the following:
auth support:
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Whether or not the target authoritative server supports
incremental deleg. "Yes" means support is registered and "No"
means support is not registered.
_deleg presence:
Whether or not the _deleg label is present in the target zone (and
thus incremental delegations) "Yes" means it is present, "No"
means it is not present, "Unknown" means this is not yet known and
"*" means it doesn't matter.
On the right side of the table are the additional follow-up queries,
to be sent in response to non-IDELEG referrals. The _deleg presence
test query (most right column) only needs to be sent to unsigned
target zones, because its non-existence will be shown in the NSEC(3)
records showing the non-existence of the incremental delegation
(second from right column).
If the query name is the same as the apex of the target zone, or the
response is a non-referral response, no additional queries need to be
sent. Otherwise:
1. If the authoritative name server supports IDELEG (Row 1), no
additional queries need to be sent.
2. If the _deleg label is known not to exist in the target zone (Row
2), no additional queries need to be sent.
3. If the _deleg label is known to exist in the target zone, but
there was no authoritative name server support in the referral
response (Row 3), an additional deleg query (Section 5.1) needs
to be sent.
4. If it is not known whether or not the _delewg label exists, and
there was no authoritative name server support in the referral
response (Row 4), an additional deleg query (Section 5.1) needs
to be sent. If the target zone is unsigned, presence of the
_deleg label needs to be tested explicitly as well (Section 5.2).
5.3.1. Reduced latency
Latency can be reduced with one round trip when the deleg query is
sent in parallel to the legacy query. This will induce more
additional queries since authoritative name server support
(eliminating the need to send deleg queries), is detected from the
legacy query.
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6. Priming queries
Some zones, such as the root zone, are targeted directly from hints
files. Information about which authoritative name servers and with
capabilities, MAY be provided in an IDELEG RRset directly at the
_deleg label under the apex of the zone. Priming queries from an
deleg supporting resolver, MUST send an _deleg.<apex> IDELEG query in
parallel to the legacy <apex> NS query and process the content as if
it was found through an referral response.
7. Limitations
The presence of the _deleg label in the delegation information
reduces that maximum length of a domain name for a zone to 248 bytes.
Note that names within zones are not limited and can still be 255
bytes.
8. How does the protocol described in this draft meet the requirements
This section will discuss how deleg meets the requirements for a new
delegation mechanism as described in [I-D.ietf-deleg-requirements-02]
* H1. DELEG must not disrupt the existing registration model of
domains.
The existing zone structure including the concept of delegations
from a parent zone to a child zone is left unchanged.
* H2. DELEG must be backwards compatible with the existing
ecosystem.
The new delegations do not interfere with legacy software.
The behavior of deleg supporting resolvers includes a fallback to
NS records if no IDELEG delegation is present (See Section 5.1).
* H3. DELEG must not negatively impact most DNS software.
Deleg introduces a new RR type. Software that parses zone file
format needs to be changed to support the new type. Though
unknown type notation [RFC3597] can be used in some cases if no
support for the new RR type is present. Existing authoritatives
can serve IDELEG zones (though less efficiently), existing signers
can sign IDELEG zones, existing diagnostic tools can query IDELEG
zones. Non-recursive DNSSEC validators can operate independently
from (possibly legacy) recursive resolvers.
* H4. DELEG must be able to secure delegations with DNSSEC.
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IDELEG delegations as described in this document are automatically
secured with DNSSEC (if the parent zone is signed). A replacement
for DS records is described in
[I-D.homburg-deleg-incremental-dnssec].
* H5. DELEG must support updates to delegation information with the
same relative ease as currently exists with NS records.
IDELEG delegations are affected by TTL like any other DNS record.
* H6. DELEG must be incrementally deployable and not require any
sort of flag day of universal change.
IDELEG zones can be added without upgrading authoritatives.
IDELEG zones still work with old resolvers and validators.
Basically any combination of old and new should work, though with
reduced efficiency for some combinations.
* H7. DELEG must allow multiple independent operators to
simultaneously serve a zone.
Deleg allows for multiple IDELEG records. This allows multiple
operators to serve the zone.
* S1. DELEG should facilitate the use of new DNS transport
mechanisms
New transports are already defined for the DNS mode of SVCB
([RFC9461]). The same parameters are used for IDELEG.
* S2. DELEG should make clear all of the necessary details for
contacting a service
Most of the needed SVCB parameters are already defined in existing
standards. The exception is a replacement for the DS records,
which is described in [I-D.homburg-deleg-incremental-dnssec].
* S3. DELEG should minimize transaction cost in its usage.
Assuming Qname-minimisation, there are no extra queries needed in
most cases if the authoritative name server has deleg support.
The exception is when the parent zone is not signed and has no
IDELEG records. In that case, one extra query is needed when the
parent zone is first contacted (and every TTL).
Additional queries may be needed to resolve aliases.
* S4. DELEG should simplify management of a zone's DNS service.
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Zone management can be simplified using the alias mode of IDELEG.
This allows the zone operator to change the details of the
delegation without involving the parent zone.
Draft [I-D.homburg-deleg-incremental-dnssec] defines the dnskeyref
parameter which offers the same simplification for DNSSEC
delegations.
* S5. DELEG should allow for backward compatibility to the
conventional NS-based delegation mechanism.
NS records and glue can be extracted from the IDELEG record
assuming no aliasing is used.
The ds parameter in [I-D.homburg-deleg-incremental-dnssec] has the
same value as the rdata of a DS record.
* S6. DELEG should be extensible and allow for the easy incremental
addition of new delegation features after initial deployment.
SVCB-style records are extensible by design.
* S7. DELEG should be able to convey a security model for
delegations stronger than currently exists with DNSSEC.
IDELEG delegations are protected by DNSSEC, unlike NS records at
the parent zone.
9. Implementation Status
*Note to the RFC Editor*: please remove this entire section before
publication.
We are using RR type code 65280 for experiments.
Jesse van Zutphen has built a proof of concept implementation
supporting IDELEG delegations as specified in a previous version of
this document [I-D.homburg-deleg-incremental-deleg-00] for the
Unbound recursive resolver as part of his master thesis for the
Security and Network Engineering master program of the University of
Amsterdam [JZUTPHEN]. Jesse's implementation has been adapted to
query for the IDELEG RR types (with code point 65280). This version
is available in the ideleg branch of the NLnetLabs/unbound github
repository [IDELEG4UNBOUND]. Note that this implementation does not
yet respond to support in the authoritative Authoritative name server
support (Section 4), and also does not yet follow AliasMode IDELEG
RRs.
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The ldns DNS library and tools software has been extended with
support for IDELEG, which is available in the features/ideleg branch
of the NLnetLabs/ldns github repository [IDELEG4LDNS]. This includes
support for IDELEG in the DNS lookup utility drill, as well as in the
DNSSEC zone signer ldns-signzone and all other tools and examples
included with the ldns software.
Wouter Petri has built a proof of concept support for IDELEG in the
NSD authoritative name server software as part of a research project
for the Security and Network Engineering master program of the
University of Amsterdam [WPETRI]. The source code of his
implementation is available on github [IDELEG4NSD].
Wouter's implementation is serving the ideleg.net. domain, containing
a variety of different IDELEG delegations, for evaluation purposes.
We are planning to provide information about the deployment,
including what software to evaluate these delegations, at
http://ideleg.net/ (http://ideleg.net/), hopefully before the IETF
122 in Bangkok (https://datatracker.ietf.org/meeting/122/
proceedings).
10. Security Considerations
Deleg moves the location of referral information to a unique location
that currently exists. However, as this is a new approach, thought
must be given to usage. There must be some checks to ensure that the
registering a _deleg subdomain happens at the time the domain is
provisioned. The same care needs to be addressed when a domain is
de-provisioned that the _deleg is removed. This is similar to what
happens to A/AAAA glue records for NS records deployed in parent
zones.
While the recommendation is to deploy DNSSEC with deleg, it is not
mandatory. However, using deleg with unsigned zones can create
possibilities of domain hijackings. This could be hard to detect
when not speaking directly to the authoritative name server. This
risk of domain hijacking is not expected to increase significantly
compared to the situation without deleg.
There are bound to be other considerations.
11. IANA Considerations
11.1. IDELEG RR type
IANA is requested to update the "Resource Record (RR) TYPEs" registry
under the "Domain Name System (DNS) Parameters" registry group as
follows:
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+========+=======+============+=================+
| TYPE | Value | Meaning | Reference |
+========+=======+============+=================+
| IDELEG | TBD | Delegation | [this document] |
+--------+-------+------------+-----------------+
Table 2
11.2. _deleg Node Name
Per [RFC8552], IANA is requested to add the following entry to the
DNS "Underscored and Globally Scoped DNS Node Names" registry:
+=========+============+=================+
| RR Type | _NODE NAME | Reference |
+=========+============+=================+
| IDELEG | _deleg | [this document] |
+---------+------------+-----------------+
Table 3: Entry in the Underscored and
Globally Scoped DNS Node Names
registry
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC3597] Gustafsson, A., "Handling of Unknown DNS Resource Record
(RR) Types", RFC 3597, DOI 10.17487/RFC3597, September
2003, <https://www.rfc-editor.org/rfc/rfc3597>.
[RFC6672] Rose, S. and W. Wijngaards, "DNAME Redirection in the
DNS", RFC 6672, DOI 10.17487/RFC6672, June 2012,
<https://www.rfc-editor.org/rfc/rfc6672>.
[RFC7858] Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D.,
and P. Hoffman, "Specification for DNS over Transport
Layer Security (TLS)", RFC 7858, DOI 10.17487/RFC7858, May
2016, <https://www.rfc-editor.org/rfc/rfc7858>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
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[RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS
(DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018,
<https://www.rfc-editor.org/rfc/rfc8484>.
[RFC8767] Lawrence, D., Kumari, W., and P. Sood, "Serving Stale Data
to Improve DNS Resiliency", RFC 8767,
DOI 10.17487/RFC8767, March 2020,
<https://www.rfc-editor.org/rfc/rfc8767>.
[RFC9250] Huitema, C., Dickinson, S., and A. Mankin, "DNS over
Dedicated QUIC Connections", RFC 9250,
DOI 10.17487/RFC9250, May 2022,
<https://www.rfc-editor.org/rfc/rfc9250>.
[RFC9460] Schwartz, B., Bishop, M., and E. Nygren, "Service Binding
and Parameter Specification via the DNS (SVCB and HTTPS
Resource Records)", RFC 9460, DOI 10.17487/RFC9460,
November 2023, <https://www.rfc-editor.org/rfc/rfc9460>.
[RFC9461] Schwartz, B., "Service Binding Mapping for DNS Servers",
RFC 9461, DOI 10.17487/RFC9461, November 2023,
<https://www.rfc-editor.org/rfc/rfc9461>.
[STD13] Internet Standard 13,
<https://www.rfc-editor.org/info/std13>.
At the time of writing, this STD comprises the following:
Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
<https://www.rfc-editor.org/info/rfc1034>.
Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
November 1987, <https://www.rfc-editor.org/info/rfc1035>.
12.2. Informative References
[BCP219] Best Current Practice 219,
<https://www.rfc-editor.org/info/bcp219>.
At the time of writing, this BCP comprises the following:
Hoffman, P. and K. Fujiwara, "DNS Terminology", BCP 219,
RFC 9499, DOI 10.17487/RFC9499, March 2024,
<https://www.rfc-editor.org/info/rfc9499>.
[I-D.homburg-deleg-incremental-deleg-00]
Homburg, P., van Zutphen, J., and W. Toorop,
"Incrementally Deployable Extensible Delegation for DNS",
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Work in Progress, Internet-Draft, draft-homburg-deleg-
incremental-deleg-00, 8 July 2024,
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Homburg, et al. Expires 5 October 2025 [Page 28]
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[IDELEG4LDNS]
Toorop, W., "A proof of concept support for IDELEG in the
ldns DNS library and tools", n.d.,
<https://github.com/NLnetLabs/ldns/tree/features/ideleg>.
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Petri, W., "A proof of concept support for IDELEG in the
NSD authoritative name server software", n.d.,
<https://github.com/WP-Official/nsd>.
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van Zutphen, J. and P. Homburg, "A proof of concept
implementation of incremental deleg", n.d.,
<https://github.com/NLnetLabs/unbound/tree/ideleg>.
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resolvers", n.d.,
<https://nlnetlabs.nl/downloads/publications/extensible-
deleg-in-resolvers_2024-07-08.pdf>.
[RFC8552] Crocker, D., "Scoped Interpretation of DNS Resource
Records through "Underscored" Naming of Attribute Leaves",
BCP 222, RFC 8552, DOI 10.17487/RFC8552, March 2019,
<https://www.rfc-editor.org/rfc/rfc8552>.
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nameservers", n.d.,
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Acknowledgments
The idea to utilize SVCB based RRs to signal capabilities was first
proposed by Tim April in [I-D.tapril-ns2].
The idea to utilize SVCB for IDELEG delegations (and also the idea
described in this document) emerged from the DNS Hackathon at the
IETF 118. The following participants contributed to this brainstorm
session: Vandan Adhvaryu, Roy Arends, David Blacka, Manu Bretelle,
Vladimír Čunát, Klaus Darilion, Peter van Dijk, Christian Elmerot,
Bob Halley, Philip Homburg, Shumon Huque, Shane Kerr, David C
Lawrence, Edward Lewis, George Michaelson, Erik Nygren, Libor Peltan,
Ben Schwartz, Petr Špaček, Jan Včelák and Ralf Weber
Authors' Addresses
Philip Homburg
NLnet Labs
Homburg, et al. Expires 5 October 2025 [Page 29]
Internet-Draft deleg April 2025
Email: philip@nlnetlabs.nl
Tim Wicinski
Cox Communications
Email: tjw.ietf@gmail.com
Jesse van Zutphen
University of Amsterdam
Email: Jesse.vanZutphen@os3.nl
Willem Toorop
NLnet Labs
Email: willem@nlnetlabs.nl
Homburg, et al. Expires 5 October 2025 [Page 30]