Internet DRAFT - draft-thomassen-dnsop-generalized-dns-notify
draft-thomassen-dnsop-generalized-dns-notify
DNSOP Working Group J. Stenstam
Internet-Draft The Swedish Internet Foundation
Intended status: Standards Track P. Thomassen
Expires: 8 February 2024 deSEC, Secure Systems Engineering
J. Levine
Standcore LLC
7 August 2023
Generalized DNS Notifications
draft-thomassen-dnsop-generalized-dns-notify-02
Abstract
Changes in CDS/CDNSKEY, CSYNC, and other records related to
delegation maintenance are usually detected through scheduled scans
run by the consuming party (e.g. top-level domain registry),
incurring an uncomfortable trade-off between scanning cost and update
latency.
A similar problem exists when scheduling zone transfers, and has been
solved using the well-known DNS NOTIFY mechanism ([RFC1996]). This
mechanism enables a primary nameserver to proactively inform
secondaries about zone changes, allowing the secondary to initiate an
ad-hoc transfer independently of when the next SOA check would be
due.
This document extends the use of DNS NOTIFY beyond conventional zone
transfer hints, bringing the benefits of ad-hoc notifications to DNS
delegation maintenance in general. Use cases include DNSSEC key
rollovers hints via NOTIFY(CDS) and NOTIFY(DNSKEY) messages, and
quicker changes to a delegation's NS record set via NOTIFY(CSYNC)
messages.
Furthermore, this document proposes a new DNS record type,
tentatively referred to as "NOTIFY record", which is used to publish
details about where generalized notifications should be sent.
TO BE REMOVED: This document is being collaborated on in Github at:
https://github.com/peterthomassen/draft-thomassen-dnsop-generalized-
dns-notify (https://github.com/peterthomassen/draft-thomassen-dnsop-
generalized-dns-notify). The most recent working version of the
document, open issues, etc. should all be available there. The
authors (gratefully) accept pull requests.
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Status of This Memo
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This Internet-Draft will expire on 8 February 2024.
Copyright Notice
Copyright (c) 2023 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
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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. Requirements Notation . . . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. Costs and Dangers of Slow Convergence . . . . . . . . . . . . 4
3. Efficiency Issues with DNS Scanning vs. Notification . . . . 5
3.1. CDS and CDNSKEY Scanners . . . . . . . . . . . . . . . . 5
3.2. CSYNC Scanners . . . . . . . . . . . . . . . . . . . . . 5
3.3. Multi-Signer Setups . . . . . . . . . . . . . . . . . . . 6
4. CDS/CDNSKEY and CSYNC Notifications . . . . . . . . . . . . . 6
4.1. Where to send CDS and CSYNC Notifications . . . . . . . . 7
4.2. How to Interpret CDS and CSYNC Notifications . . . . . . 8
5. DNSKEY Notifications . . . . . . . . . . . . . . . . . . . . 9
5.1. Where to send DNSKEY Notifications . . . . . . . . . . . 9
5.2. How to Interpret DNSKEY Notifications . . . . . . . . . . 10
6. Who Should Send the Notifications? . . . . . . . . . . . . . 10
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7. Timing Considerations . . . . . . . . . . . . . . . . . . . . 10
8. The Format of the NOTIFY Record . . . . . . . . . . . . . . . 11
9. Open Questions . . . . . . . . . . . . . . . . . . . . . . . 11
9.1. Rationale for a new record type, "NOTIFY" . . . . . . . . 11
9.2. Rationale for Keeping DNS Message Format and Transport . 12
9.3. Open Question For DNSKEY Notifications . . . . . . . . . 13
10. Out of Scope . . . . . . . . . . . . . . . . . . . . . . . . 13
11. Security Considerations . . . . . . . . . . . . . . . . . . . 13
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
14. Normative References . . . . . . . . . . . . . . . . . . . . 14
Appendix A. Change History (to be removed before publication) . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
This document introduces a generalization of the DNS NOTIFY mechanism
described in [RFC1996].
Traditional DNS notifications, which are here referred to as
"NOTIFY(SOA)", are sent from a primary server to a secondary server
to minimize the latter's convergence time to a new version of the
zone. This mechanism successfully addresses a significant
inefficiency in the original protocol.
Today there are several new cases where similar inefficiencies cause
significant problems. However, just as in the NOTIFY(SOA) case, a
new set of notification types will have a major positive benefit by
allowing the DNS infrastructure to completely sidestep these
inefficiencies.
There are no DNS protocol changes introduced by this document.
There are, however, proposals for how to interpret a wider range of
DNS messages that are already allowed (but not used) by the protocol.
Readers are expected to be familiar with DNSSEC, including [RFC4033],
[RFC4034], [RFC4035], [RFC6781], [RFC7344], [RFC7477], [RFC7583], and
[RFC8901].
1.1. Requirements Notation
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.
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1.2. Terminology
In the text below there are two different uses of the term "NOTIFY".
One refers to the NOTIFY message, sent from a DNSSEC signer or name
server to a notification target (for subsequent processing). We
refer to this message as NOTIFY(RRtype) where the RRtype indicates
the type of NOTIFY message (CDS, CSYNC or DNSKEY respectively).
The second is a proposed new DNS record type, with the suggested
mnemonic "NOTIFY". This record is used to publish the location of
the notification target. We refer to this as the "NOTIFY record".
2. Costs and Dangers of Slow Convergence
[RFC1996] introduced the concept of a DNS Notify message which was
used to improve the convergence time for secondary servers when a DNS
zone had been updated in the primary. The basic idea was to augment
the traditional "pull" mechanism (a periodic SOA query) with a "push"
mechanism (a Notify) for a common case that was otherwise very
inefficient (due to either slow convergence or wasteful overly
frequent scanning of the primary for changes).
Today we have similar issues with slow updates of DNS data in spite
of the data having been published. The two most obvious cases are
the scalability issues of modern CDS and CSYNC scanners that are
beginning to be deployed in a growing number of TLD registries.
Because of the large number of child delegations, scanning for CDS
and CSYNC records is rather slow (as in infrequent).
Another use case is for so-called "multi-signer" setups where there
are multiple, semi-independent, "signers" that each sign the same
zone, but with individual sets of keys. One requirement for multi-
signer setups to work is the ability to insert additional DNSKEY
records in each signer's version of the zone. (This is not the only
multi-signer requirement, but it is the one that matters here.) The
problem here is that modern signers will commonly roll DNSSEC Zone
Signing Keys automatically and without informing anyone, assuming a
single-signer setup where ZSK rollovers are a local matter (as
opposed to KSK rollovers that involve the parent). As a result, when
the ZSKs of one signer are rolled, the other signers will be unaware
of this event. However, to enable validation of signatures using a
new ZSK, it needs to be announced by all nameservers that are
authoritative for the child. To achieve this, it is therefore
necessary to bring the signers' DNSKEY RRsets back in sync. Such re-
synchronization can either happen based on a schedule, or on demand,
given a suitable trigger.
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3. Efficiency Issues with DNS Scanning vs. Notification
The original problem that [RFC1996] addressed was the problem of
optimization between frequent checking for new versions of a zone by
a secondary and infrequent checking. While it is possible to
indicate how frequently checks should occur (via the SOA Refresh
parameter), these checks did not allow catching zone changes that
fall between checkpoints. NOTIFY replaces scheduled scanning with a
more efficient mechanism.
In modern DNS infrastructure there are several new scanning-based
inefficiencies that did not exist at the time of the writing of
[RFC1996].
3.1. CDS and CDNSKEY Scanners
An increasing number of TLD registries are implementing periodic
scanning for CDS and CDNSKEY records in child zones. Because of the
large number of delegations this is rather costly, especially as it
is only a very small number of the signed delegations that will have
updated the CDS or CDNSKEY record between two scanning runs.
Frequent scanning is costly. Infrequent scanning causes slower
convergence (i.e. delay until the DS in the parent is updated).
Not every zone runs a CDS or CSYNC scanner (today). However, for
those that do, the problem is actually worse than in the traditional
primary to secondary case. The reason is that in the original case
the primary is able to indicate how frequently changes are to be
expected (via the SOA Refresh parameter). No equivalent mechanism
exist for the new scanning services.
3.2. CSYNC Scanners
This is basically the same problem as for the CDS / CDNSKEY scanners:
large number of delegations vs infrequent updates to the CSYNC record
in the child zones.
Frequent scanning is costly. Infrequent scanning causes slower
convergence (i.e. delay until the delegation information in the
parent is updated).
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3.3. Multi-Signer Setups
[I-D.wisser-dnssec-automation] describes processes for managing
signed zones using multiple semi-independent "signers" (i.e. services
that take an unsigned zone, sign it using unique DNSKEYs and publish
the zone on the public Internet). The setup most commonly discussed
for multi-signer uses a "multi-signer controller" which is a separate
service responsible for keeping the signing and delegation
information in sync across multiple signers.
To keep information in sync, the signers need to be scanned for
current information about the DNSKEY RRset in each signer. The
problem is that modern "signers" will typically do DNSKEY rollovers
(especially ZSK rollovers) automatically without informing anyone
else, because a single-signer setup is often assumed (in which case
the ZSK rollover is a matter completely internal to the signer).
In the multi-signer case, this is not a correct assumption. It is
therefore necessary to run polls frequently to minimize the time
window between one signer changing its version of the DNSKEY RRset
and the controller noticing and re-synchronizing all signers.
Frequent scanning: costly. Infrequent scanning: slower convergence
(i.e. longer potential inconsistency across signers).
4. CDS/CDNSKEY and CSYNC Notifications
The [RFC1996] NOTIFY message sends a SOA record in the Query Section.
We refer to this as a NOTIFY(SOA). By generalizing the concept of
DNS NOTIFY it is possible to address not only the original
inefficiency (primary name server to secondary nameserver
convergence) but also the problems with CDS/CDNSKEY, CSYNC and Multi-
Signer scanning for zone updates.
The CDS/CDNSKEY inefficiency may be addressed by the child sending a
NOTIFY(CDS) to an address where the parent listens for such
notifications.
While the receiving side will often be a scanning service provided by
the registry itself, it is expected that in the ICANN RRR model, some
registries will prefer registrars to conduct CDS/CDNSKEY scans. For
such parents, the receiving service should notify the appropriate
registrar, over any communication channel deemed suitable between
registry and registrar (such as EPP, or possibly by forwarding the
actual NOTIFY(CDS) or NOTIFY(CSYNC) directly). Such internal
processing is inconsequential from the perspective of the child: the
NOTIFY packet is simply sent to the notification address.
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To address the CDS/CDNSKEY dichotomy, NOTIFY(CDS) is defined to
indicate any child-side changes pertaining to a upcoming update of DS
records. Upon receipt of NOTIFY(CDS), the parent SHOULD initiate the
same scan that would otherwise be triggered based on a timer.
The CSYNC inefficiency may similarly be addressed by the child
sending a NOTIFY(CSYNC) to an address where the parent is listening
to CSYNC notifications.
In both cases the notification will speed up the CDS and CSYNC
scanning by providing the parent with a hint that a particular child
zone has published new CDS, CDNSKEY and/or CSYNC records.
The DNS protocol already allows these new notification types, so no
protocol change is required. The only thing needed is specification
of where to send the new types of Notifies and how to interpret them
in the receiving end.
4.1. Where to send CDS and CSYNC Notifications
In the case of NOTIFY(CDS) and NOTIFY(CSYNC) the ultimate recipient
of the notification is the parent, to improve the speed and
efficiency of the parent's CDS/CSYNC scanning. Because the name of
the parent zone is known, and because the parent obviously controls
the contents of its own zone the simplest solution is for the parent
to publish the address where it prefers to have notifications sent.
However, there may exist cases where this scheme (sending the
notification to the parent) is not sufficient and a more general
design is needed. At the same time, it is strongly desireable that
the child is able to figure out where to send the NOTIFY via a single
query.
By adding the following to the zone parent.:
parent. IN NOTIFY CDS scheme port scanner.parent.
parent. IN NOTIFY CSYNC scheme port scanner.parent.
where the only scheme defined here is scheme=1 with the
interpretation that when a new CDS (or CDNSKEY or CSYNC) is
published, a NOTIFY(CDS) or NOTIFY(CSYNC) should be sent to the
address and port listed in the corresponding NOTIFY RRset.
Example:
parent. IN NOTIFY CDS 1 5359 cds-scanner.parent.
parent. IN NOTIFY CSYNC 1 5360 csync-scanner.parent.
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Other schemes are possible, but are out of scope for this document.
The suggested mnemonic for the new record type is "NOTIFY" and it is
further described below.
4.2. How to Interpret CDS and CSYNC Notifications
Upon receipt of a NOTIFY(CDS) for a particular child zone at the
published address for CDS notifications, the parent has two options:
1. Schedule an immediate check of the CDS and CDNSKEY RRsets as
published by that particular child zone.
If the check finds that the CDS/CDNSKEY RRset has indeed changed,
the parent MAY reset the scanning timer for children for which
NOTIFY(CDS) is received, or reduce the periodic scanning
frequency accordingly (e.g. to every two weeks). This will
decrease the scanning effort for the parent. If a CDS/CDNSKEY
change is then detected (without having received a notification),
the parent SHOULD clear that state and revert to the default
scanning schedule.
Parents introducing CDS/CDNSKEY scanning support at the same time
as NOTIFY(CDS) support are not in danger of breaking children's
scanning assumption, and MAY therefore use a low-frequency
scanning schedule in default mode.
2. Ignore the notification, in which case the system works exactly
as before.
If the parent implements the first option, the convergence time (time
between publication of a new CDS and propagation of the resulting DS)
will decrease significantly, thereby providing improved service to
the child zone.
If the parent, in addition to scheduling an immediate check for the
child zone of the notification, also choses to modify the scanning
schedule (to be less frequent), the cost of providing the scanning
service will be reduced.
Upon receipt of a NOTIFY(CSYNC) to the published address for CSYNC
notifications, the parent has exactly the same options to choose
among as for the NOTIFY(CDS).
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5. DNSKEY Notifications
In the multi-signer case the problem is slightly different, because
it is not the parent that should be notified, but rather a third
party.
5.1. Where to send DNSKEY Notifications
The question is how the multi-signer controller should inform the
signer about where to send the notification. In the NOTIFY(CDS) and
NOTIFY(CSYNC) cases the child (the service that signs the child zone)
knows the name of the parent zone and can look up the notification
address there. In the NOTIFY(DNSKEY) case, there is no trivial
target.
However, it is possible to look up the notification address in the
child zone itself. This translates into a requirement for multi-
signer setups, namely that at least one external party (typically a
multi-signer controller) has the ability to insert or modify RRsets
in the child zone. Therefore the controller should be able to insert
a record that documents the wanted notification address for
NOTIFY(DNSKEY) messages.
Also in the NOTIFY(DNSKEY) case there is the possibility that this
scheme will not be sufficient for all cases. And therefore the
proposed design (in analogy with the NOTIFY(CDS) and NOTIFY(CSYNC)
cases) is:
child.parent. IN NOTIFY DNSKEY scheme port scanner.signerA.
child.parent. IN NOTIFY DNSKEY scheme port scanner.signerB.
with the only defined scheme at this time being scheme=1 with the
interpretation that whenever there are changes to the DNSKEY RRset in
a signer it should send a corresponding NOTIFY(DNSKEY) to all
notification addresses listed in the "child.parent. NOTIFY" RRset.
Example:
child.parent. IN NOTIFY DNSKEY 1 5361 scanner.signerA.
child.parent. IN NOTIFY DNSKEY 1 5361 scanner.signerB.
child.parent. IN NOTIFY DNSKEY 1 5361 ctrl.multi-signer.example.
Other schemes are possible, but are out of scope for this document.
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5.2. How to Interpret DNSKEY Notifications
The receipt of a NOTIFY(DNSKEY) is a hint that the DNSKEY RRset at
the sending signer has been updated. If the child zone is not part
of a multi-signer setup this should be a no-op that does not cause
any action. In a multi-signer setup, though, this hint provides the
recipient of the notification with the same options as in the
NOTIFY(CDS) and NOTIFY(CSYNC) cases: schedule an immediate check, or
ignore.
6. Who Should Send the Notifications?
Because of the security model where a notification by itself never
causes a change (it can only speed up the time until the next check
for the same thing), the sender's identity is not crucial.
This opens up the possibility of having the controller in a multi-
signer setup send the CDS and CSYNC notifications to the parent,
thereby enabling this new functionality even before the emergence of
support for generalized DNS notifications in the name servers used
for signing.
However, as multi-signer is strongly dependent on DNSKEY
notifications (which, in case of an automatic ZSK rollover, can only
be generated by the signing software), this does not alleviate the
need for modifications also to signing software to support
NOTIFY(DNSKEY).
7. Timing Considerations
When a primary name server publishes a new CDS RRset there will be a
time delay until all copies of the zone world-wide will have been
updated. Usually this delay is short (on the order of seconds), but
it is larger than zero. If the primary sends a NOTIFY(CDS) at the
exact time of publication of the new zone there is a potential for
the parent to schedule the CDS check that the notification triggers
faster than the zone propagates to all secondaries. In this case the
parent may draw the wrong conclusion ("the CDS RRset has not been
updated").
Having a delay between the publication of the new data and the check
for the new data would alleviate this issue. However, as the parent
has no way of knowing how quickly the child zone propagates, the
appropriate amount of delay is uncertain. It is therefore
RECOMMENDED that the child delays sending NOTIFY packets to the
parent until a consistent public view of the pertinent records is
ensured.
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NOTIFY(CSYNC) has the same timing consideration as NOTIFY(CDS) while
NOTIFY(DNSKEY) does not.
8. The Format of the NOTIFY Record
Here is the format of the NOTIFY RR, whose DNS type code is not yet
defined.
Name TTL Class NOTIFY RRtype Scheme Port Target
Name The zone this RR refers to. In the case of NOTIFY(CDS) and
NOTIFY(CSYNC) this is the name of the parent zone. In the case of
NOTIFY(DNSKEY) this is the name of the zone in which a change in the
DNSKEY RRset is taking place.
TTL Standard DNS meaning [RFC 1035].
Class Standard DNS meaning [RFC 1035]. NOTIFY records occur in the
IN Class.
RRtype The type of generalized NOTIFY that this NOTIFY RR defines the
desired target address for. Currently only the types CDS, CSYNC and
DNSKEY are suggested to be supported, but there is no protocol issue
should a use case for additional types of notifications arise in the
future.
Scheme The scheme for locating the desired notification address. The
range is 0-255. This is a 16 bit unsigned integer in network byte
order. The value 0 is an error. The value 1 is described in this
document and all other values are currently unspecified.
Port The port on the target host of the notification service. The
range is 0-65535. This is a 16 bit unsigned integer in network byte
order.
Target The domain name of the target host providing the service of
listening for generalized notifications of the specified type. This
name MUST resolve to one or more address records.
9. Open Questions
9.1. Rationale for a new record type, "NOTIFY"
It is technically possible to store the same information in an SRV
record as in the proposed NOTIFY record. This would, however,
require name space pollution (indicating the RRtype via a label in
the owner name) and also changing the semantics of one of the integer
fields of the SRV record.
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Overloading semantics on a single record type has not been a good
idea in the past. Furthermore, as the generalized notifications are
a new proposal with no prior deployment on the public Internet there
is an opportunity to avoid repeating previous mistakes.
In the case of the "vertical" NOTIFY(CDS) and NOTIFY(CSYNC), no
special processing needs to be applied by the authoritative
nameserver upon insertion of the record indicating the notification
target. The nameserver can be "unaware"; a conventional SRV record
would therefore suffice from a processing point of view. In the case
of the more "horizontal" NOTIFY(DNSKEY), however, the nameserver will
have to act on the insertion of a
zone.example. IN NOTIFY DNSKEY ...
record.
A new record type would therefore make it possible to more easily
associate the special processing with the record's insertion. The
NOTIFY record type would provide a cleaner solution to all the new
types of notification signaling. Eg.:
parent. IN NOTIFY CDS 1 59 scanner.parent.
parent. IN NOTIFY CSYNC 1 59 scanner.parent.
child.parent. IN NOTIFY DNSKEY 1 5900 ctrl.multi-signer.example.
9.2. Rationale for Keeping DNS Message Format and Transport
In the most common cases of using generalized notifications the
recipient is expected to not be a nameserver, but rather some other
type of service, like a CDS/CSYNC scanner.
However, this will likely not always be true. In particular it seems
likely that in cases where the parent is not a large delegation-
centric zone like a TLD, but rather a smaller zone with a small
number of delegations there will not be separate services for
everything and the recipient of the NOTIFY(CDS) or NOTIFY(CSYNC) will
be an authoritative nameserver for the parent zone.
Another case where this seems likely is in controller-less multi-
signer setups where there is no central controller. Instead the
multi-signer algorithms will be implemented inside or near each
participating signer. Also in these cases it seems likely that the
recipient in some cases will be an authoritative nameserver.
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For this reason it seems most reasonable to stay within the the well
documented and already supported message format specified in RFC 1996
and delivered over normal DNS transport, although not necessarily to
port 53.
9.3. Open Question For DNSKEY Notifications
In a multi-signer setup there are multiple signers. How will the
multi-signer controller know which signer sent the notification? As
the number of signers for a particular zone is low (typically 2 or
possibly 3), there is no major problem caused by not knowing which
signer sent the notification and instead always check all the signers
for updates to the DNSKEY RRset.
10. Out of Scope
To accommodate ICANN's RRR model, the parent's designated
notification target may forward NOTIFY(CDS) messages to the
registrar, e.g. via EPP or by forwarding the NOTIFY(CDS) message
directly. The same is true also for NOTIFY(CSYNC).
From the perspective of this protocol, the NOTIFY(CDS) packet is
simply sent to the parent's listener address. However, should this
turn out not to be sufficient, it is possible to define a new
"scheme" that specifies alternative logic for dealing with such
requirements. Description of internal processing in the recipient
end or for locating the recipient are out of scope of this document.
In the multi-signer case, where the same zone is signed by multiple
semi-independent "signers" it is obviously necessary to devise means
of keeping the non-DNSSEC contents of the zone in sync. That is out
of scope of the multi-signer work and also out of scope of this
document.
A corner case of this scoping regards making changes to the NS RRset.
Individual signers (as in DNS service providers) may want to be able
to make such changes independently of the other contents of the zone.
11. Security Considerations
The original NOTIFY specification ([RFC1996]) sidesteps most security
issues by not relying on the information in the NOTIFY message in any
way but instead only use it to set the timer until the next scheduled
check (for the SOA record) to zero. Therefore it is impossible to
affect the behaviour of the recipient of the NOTIFY other than by
changing the timing for when different checks are initiated.
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This mechanism and security model is reused for all the generalized
NOTIFY messages.
Another consideration is whether generalized DNS Notifications can be
used as an amplification attack. The answer seems to be "NO",
because the size of the generalized NOTIFY messages is mostly equal
to the size of the response and it is also mostly equal to the size
of the resulting outbound query (for the child zone's CDS, CSYNC or
DNSKEY RRset).
Hence the amplification attack potential of generalized Notifications
is the same as for the original NOTIFY(SOA), which has never been
found to be useful for amplification attacks.
In any case, NOTIFY consumers MAY configure rate limits to address
concerns about the impact of unsolicited NOTIFY messages.
12. IANA Considerations
Per [RFC8552], IANA is requested to create a new registry on the
"Domain Name System (DNS) Parameters" IANA web page as follows:
Name: Generalized DNS Notifications
Assignment Policy: Expert Review
Reference: [this document]
+=============+========+==========+=================+
| NOTIFY type | Scheme | Location | Reference |
+=============+========+==========+=================+
| CDS | 1 | parent. | [this document] |
+-------------+--------+----------+-----------------+
| CSYNC | 1 | parent. | [this document] |
+-------------+--------+----------+-----------------+
| DNSKEY | 1 | zone. | [this document] |
+-------------+--------+----------+-----------------+
Table 1
13. Acknowledgements
Joe Abley, Mark Andrews, Christian Elmerot, Olafur Gu[eth]mundsson,
Paul Wouters, Brian Dickson
14. Normative References
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[I-D.wisser-dnssec-automation]
Wisser, U. and S. Huque, "DNSSEC automation", Work in
Progress, Internet-Draft, draft-wisser-dnssec-automation-
03, 6 March 2022, <https://datatracker.ietf.org/doc/html/
draft-wisser-dnssec-automation-03>.
[RFC1996] Vixie, P., "A Mechanism for Prompt Notification of Zone
Changes (DNS NOTIFY)", RFC 1996, DOI 10.17487/RFC1996,
August 1996, <https://www.rfc-editor.org/rfc/rfc1996>.
[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>.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements",
RFC 4033, DOI 10.17487/RFC4033, March 2005,
<https://www.rfc-editor.org/rfc/rfc4033>.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, DOI 10.17487/RFC4034, March 2005,
<https://www.rfc-editor.org/rfc/rfc4034>.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
<https://www.rfc-editor.org/rfc/rfc4035>.
[RFC6781] Kolkman, O., Mekking, W., and R. Gieben, "DNSSEC
Operational Practices, Version 2", RFC 6781,
DOI 10.17487/RFC6781, December 2012,
<https://www.rfc-editor.org/rfc/rfc6781>.
[RFC7344] Kumari, W., Gudmundsson, O., and G. Barwood, "Automating
DNSSEC Delegation Trust Maintenance", RFC 7344,
DOI 10.17487/RFC7344, September 2014,
<https://www.rfc-editor.org/rfc/rfc7344>.
[RFC7477] Hardaker, W., "Child-to-Parent Synchronization in DNS",
RFC 7477, DOI 10.17487/RFC7477, March 2015,
<https://www.rfc-editor.org/rfc/rfc7477>.
[RFC7583] Morris, S., Ihren, J., Dickinson, J., and W. Mekking,
"DNSSEC Key Rollover Timing Considerations", RFC 7583,
DOI 10.17487/RFC7583, October 2015,
<https://www.rfc-editor.org/rfc/rfc7583>.
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[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>.
[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>.
[RFC8901] Huque, S., Aras, P., Dickinson, J., Vcelak, J., and D.
Blacka, "Multi-Signer DNSSEC Models", RFC 8901,
DOI 10.17487/RFC8901, September 2020,
<https://www.rfc-editor.org/rfc/rfc8901>.
Appendix A. Change History (to be removed before publication)
* draft-thomassen-dnsop-generalized-dns-notify-02
Add rationale for staying in band
Add John as an author
* draft-thomassen-dnsop-generalized-dns-notify-01
Mention Ry-to-Rr forwarding to accommodate RRR model
Add port number flexiblity
Add scheme parameter
Drop SRV-based alternative in favour of new NOTIFY RR
Editorial improvements
* draft-thomassen-dnsop-generalized-dns-notify-00
Initial public draft.
Authors' Addresses
Johan Stenstam
The Swedish Internet Foundation
Email: johan.stenstam@internetstiftelsen.se
Peter Thomassen
deSEC, Secure Systems Engineering
Email: peter@desec.io
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John Levine
Standcore LLC
Email: standards@standcore.com
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