Brokered Agent Network for DNS AI Discovery
draft-mozleywilliams-dnsop-bandaid-00

Abstract

The emerging field of agent-to-agent protocol standards introduces
new requirements in order to facilitate discovery, trust signaling,
session negotiation and communication. This document specifies a
method for utilizing the Domain Name System (DNS) to facilitate
scalable and interoperable discovery between AI agents. The proposed
mechanism, referred to as _Brokered Agent Network for DNS AI
Discovery_ (BANDAID), defines a structured DNS namespace and record
usage model to support metadata exchange and capability
advertisement.

BANDAID introduces a leaf zone convention (e.g., _agents.example.com)
containing Service Binding (SVCB) records (e.g.,
chat._agents.example.com) that encode application-specific metadata.
These records enable agents to retrieve operational parameters prior
to initiating a session, supporting both targeted lookups and
capability-based discovery. The approach leverages existing DNS
infrastructure, including DNS Service Discovery (DNS-SD), DNSSEC, and
DANE, to provide integrity, authenticity, and automation without
requiring human intervention. Lastly, the draft for Domain Control
Validation (DCV) proposes a best current practice to prove an agent
is authorized to act on behalf of a domain.

_This document proposes no change to the structure of DNS messages,
and no new operation codes, response codes, resource record types, or
any other new DNS protocol values._

About This Document

This note is to be removed before publishing as an RFC.

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The latest revision of this draft can be found at
https://example.com/LATEST. Status information for this document may
be found at https://datatracker.ietf.org/doc/draft-mozleywilliams-
dnsop-bandaid/.

Discussion of this document takes place on the WG Working Group
mailing list (mailto:WG@example.com), which is archived at
https://example.com/WG.

Source for this draft and an issue tracker can be found at
https://github.com/USER/REPO.

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 19 April 2026.

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Table of Contents

1. Conventions and Definitions . . . . . . . . . . . . . . . . . 4
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4

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2.1. Challenges with Existing Proposed Mechanisms and Benefits
of DNS . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.1. Development . . . . . . . . . . . . . . . . . . . . . 6
2.1.2. Opportunity Cost . . . . . . . . . . . . . . . . . . 6
2.1.3. Governance . . . . . . . . . . . . . . . . . . . . . 7
2.1.4. Sovereignty . . . . . . . . . . . . . . . . . . . . . 8
2.1.5. Commerce . . . . . . . . . . . . . . . . . . . . . . 8
2.1.6. Application . . . . . . . . . . . . . . . . . . . . . 9
2.1.7. Granularity . . . . . . . . . . . . . . . . . . . . . 9
2.1.8. Performance . . . . . . . . . . . . . . . . . . . . . 10
2.1.9. Lifecycle / Management . . . . . . . . . . . . . . . 10
2.1.10. Trust . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1.11. Agent Properties . . . . . . . . . . . . . . . . . . 11
2.1.12. Control . . . . . . . . . . . . . . . . . . . . . . . 12
2.2. Mechanisms for Successful Agent Communication . . . . . . 13
2.2.1. Service Binding Records, aka SVCB . . . . . . . . . . 13
2.2.2. DNS Security Extensions, aka DNSSEC . . . . . . . . . 14
2.2.3. DNS Service Discovery, aka DNS-SD . . . . . . . . . . 15
2.2.4. DNS-Based Authentication of Named Entities, aka
DANE . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.5. Domain Control Validation, aka DCV . . . . . . . . . 16
2.2.6. Service Resilience . . . . . . . . . . . . . . . . . 17
2.2.7. Observability, Auditability . . . . . . . . . . . . . 17
2.2.8. Interoperability . . . . . . . . . . . . . . . . . . 18
2.2.9. Multitenancy, Federation . . . . . . . . . . . . . . 18
2.3. Architecture . . . . . . . . . . . . . . . . . . . . . . 18
2.3.1. Example Communication . . . . . . . . . . . . . . . . 18
2.3.2. Example Record . . . . . . . . . . . . . . . . . . . 18
2.3.3. Example Use Cases . . . . . . . . . . . . . . . . . . 19
3. BANDAID Overview . . . . . . . . . . . . . . . . . . . . . . 20
3.1. Zone and Other Requirements . . . . . . . . . . . . . . . 20
3.1.1. Delegation and Chain of Trust . . . . . . . . . . . . 20
3.1.2. Algorithms and Parameters . . . . . . . . . . . . . . 21
3.1.3. Authenticated Denial of Existence . . . . . . . . . . 21
3.1.4. Signature Validity . . . . . . . . . . . . . . . . . 21
3.1.5. Key Rollover . . . . . . . . . . . . . . . . . . . . 21
3.1.6. Transport and Message Size . . . . . . . . . . . . . 22
3.1.7. Transfer and Integrity . . . . . . . . . . . . . . . 22
3.1.8. Monitoring . . . . . . . . . . . . . . . . . . . . . 22
3.1.9. Abuse Resistance . . . . . . . . . . . . . . . . . . 22
3.1.10. BANDAID Records . . . . . . . . . . . . . . . . . . . 22
3.1.11. Performance Optimization(s) . . . . . . . . . . . . . 23
3.1.12. Customization(s) . . . . . . . . . . . . . . . . . . 24
4. Implementation Guidance . . . . . . . . . . . . . . . . . . . 25
4.1. AI Operators . . . . . . . . . . . . . . . . . . . . . . 25
4.1.1. Separation of Roles . . . . . . . . . . . . . . . . . 25
4.1.2. Local Root Zone Copy . . . . . . . . . . . . . . . . 25
4.1.3. Aggressive Caching and Prefetch . . . . . . . . . . . 25

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4.1.4. EDNS(0) Transport Resilience . . . . . . . . . . . . 26
4.1.5. Load Distribution . . . . . . . . . . . . . . . . . . 26
4.1.6. Monitoring and Telemetry . . . . . . . . . . . . . . 26
4.1.7. Encrypted Resolver Steering (Informative) . . . . . . 27
4.2. AI Consumers . . . . . . . . . . . . . . . . . . . . . . 27
4.2.1. DNS-Based Service Discovery . . . . . . . . . . . . . 27
4.2.2. Communication Failure / Retry . . . . . . . . . . . . 27
4.2.3. Domain Control Validation . . . . . . . . . . . . . . 28
4.3. AI Developers . . . . . . . . . . . . . . . . . . . . . . 28
4.3.1. Publishing Schema . . . . . . . . . . . . . . . . . . 28
4.3.2. TTLs, Update Agility . . . . . . . . . . . . . . . . 28
4.3.3. Capability Retrieval . . . . . . . . . . . . . . . . 29
4.3.4. Example DCV Flow . . . . . . . . . . . . . . . . . . 29
4.3.5. Example Zonefile . . . . . . . . . . . . . . . . . . 29
5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 32
5.1. Future Work & Unaddressed Portions . . . . . . . . . . . 32
6. Security Considerations . . . . . . . . . . . . . . . . . . . 33
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 33
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 33
8.1. Normative References . . . . . . . . . . . . . . . . . . 33
8.2. Informative References . . . . . . . . . . . . . . . . . 33
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 37
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37

1. Conventions and Definitions

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.

2. Introduction

Agent-to-agent communication introduces novel requirements for
service discovery, authorization signaling, and metadata exchange.
While several proposals have explored new discovery protocols, the
DNS remains the most widely deployed and interoperable mechanism for
service discovery, with decades of operational maturity. Existing
DNS record types (including SRV, NAPTR, SVCB, TXT, and A/AAAA) are
routinely used to locate services and convey configuration metadata.
It is therefore reasonable to assume that AI agents will interact
with this network protocol during discovery, session initiation, and
their application exchange.

If a user at $company asks their agent "clean up my Salesforce data
based on this email," how does $company agent then know where to find
Salesforce's agents? How would the Salesforce agent validate the

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$company agent and make the correct requested changes to Salesforce
data? The former question is a DNS-solvable problem, the latter is
not in the scope of this draft.

DNS can convey authorization and intent: DNS provides an organization
a way to indicate that an agent is authorized to act on behalf of a
domain (DCV draft), publish allowed endpoints or capabilities (SVCB),
advertise service metadata in a way that’s cacheable, verifiable, and
language-agnostic (tree domain etc), all while creating tamper-proof
records and binding identities to certificates (DNSSEC + DANE).
Additionally, DNS contributes to agent security by enabling
connections to trusted nameservers, mitigating risks from
typosquatted or malicious domains, and enforcing geographic or
jurisdictional boundaries through country-code top-level domains
(ccTLDs) and regionally scoped authoritative servers. These features
collectively support secure, policy-compliant agent interactions at
scale.

Unlike proposals that rely on centralized registries or ungoverned
discovery networks, BANDAID builds upon existing infrastructure and
governance models. It preserves operator sovereignty, supports
decentralized publication, and benefits from support in the form of
legal dispute processes and vulnerability disclosure programs.

This document aims to address key concerns in governance, commerce,
security, and performance, allowing agent protocol designers to focus
on data exchange standards while relying on the DNS for discovery.
Agent-to-agent communication would take place after initial
discovery, but some key data can be put into the DNS as a shortcut to
make it more efficient.

The problem statement addressed by this draft is
[I-D.draft-mozley-aidiscovery] and also relevant is
[I-D.draft-rosenberg-ai-protocols] although this draft is related to
the discovery of agents rather than protocols used directly in agent-
to-agent communication.

2.1. Challenges with Existing Proposed Mechanisms and Benefits of DNS

Several alternative approaches to agent discovery have been proposed,
including centralized registries, blockchain-based naming systems,
and proprietary service directories. While these models may offer
novel features, they introduce significant architectural,
operational, and governance challenges. Centralized registries
concentrate control and introduce single points of failure, limiting
resilience and scalability.

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Blockchain-based systems often lack integration with existing
internet infrastructure, suffer from latency and cost constraints,
and present jurisdictional ambiguity due to decentralized governance.
Proprietary directories fragment the discovery ecosystem and inhibit
interoperability across agent frameworks and administrative domains.
Furthermore, securely delegating authority to AI solution providers
on behalf of your organization requires interfacing between this
central authority as opposed to business-to-business.

2.1.1. Development

The DNS benefits from decades of global development and operational
deployment. It is supported by mature ecosystems for vulnerability
disclosure, patch management, and protocol evolution, with active
participation from security researchers, vendors, and operators
worldwide. This distributed development model ensures that no single
entity maintains disproportionate control over the protocol’s
trajectory or security posture.

DNS infrastructure is also tightly integrated with existing
cybersecurity practices. Connections to trusted nameservers,
protections against typosquatted or malicious domains, and support
for jurisdictional scoping via country-code top-level domains
(ccTLDs) contribute to a robust security baseline. These features
are particularly relevant in agent-to-agent contexts, where automated
systems make trust decisions without human oversight... and
importantly, may be maliciously modified without human awareness.

In contrast, the introduction of a novel discovery protocol would
require the establishment of new governance structures, security
models, and operational tooling. Early implementations would likely
be centralized among a limited set of stakeholders, introducing
bottlenecks in protocol evolution and risk mitigation. Building a
comparable ecosystem would require sustained investment, cross-
organizational coordination, and long-term trust-building—resources
that DNS already possesses.

2.1.2. Opportunity Cost

Introducing a new protocol for agent-to-agent discovery imposes
nontrivial infrastructure and operational requirements. In
particular, organizations may be required to deploy and maintain
additional components such as specialized cache servers or registry
interfaces, which increases complexity and operational overhead.
Some proposals suggest a generic top level domain (gTLD) like
.aiagent, which is more cost to advertise as domains are purchased by
early opportunists. These requirements may present barriers to
adoption, especially for small or resource-constrained entities, and

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risk reinforcing disparities in access to AI technologies.

DNS, by contrast, is already deeply integrated into global
infrastructure and supported by mature tooling, operational
expertise, and deployment models. Its use for agent discovery
enables rapid adoption without introducing new layers of technical
debt. Leveraging DNS allows organizations to participate in agent-
to-agent ecosystems using existing infrastructure, reducing
onboarding friction and accelerating innovation. This approach
supports incremental deployment and minimizes opportunity cost by
avoiding the need for parallel protocol development and
infrastructure investment.

2.1.3. Governance

The DNS operates within a well-established and internationally
recognized governance framework. Oversight is provided by entities
such as the Internet Assigned Numbers Authority (IANA), top-level
domain (TLD) operators, and national network information centers
(NICs). These organizations maintain accountability mechanisms and
support dispute resolution processes, including domain takedowns,
mitigation of impersonation, and remediation of malicious behavior.
The governance structures surrounding DNS have evolved over decades
and are supported by legal, technical, and operational norms that
facilitate cross-jurisdictional trust and stability.

DNS also enables policy enforcement at the infrastructure level. For
example, country-code top-level domains (ccTLDs) and regionally
scoped authoritative servers allow for jurisdictional boundaries to
be respected, which may be relevant in agent deployments subject to
regulatory constraints. Additionally, DNSSEC and DANE provide
cryptographic assurances that bind domain identities to certificates,
supporting automated trust decisions without requiring centralized
registries or manual validation.

In contrast, alternative discovery proposals—such as blockchain-based
registries or neutral third-party systems—lack formal integration
with existing governance bodies and may be susceptible to
fragmentation, influence, or jurisdictional ambiguity. These models
do not currently offer the same level of operational recourse or
reliability. Leveraging DNS for agent discovery allows organizations
to build on trusted infrastructure while maintaining compatibility
with existing governance frameworks, providing a stable foundation
for innovation as more experimental models mature.

Establishing a new governance structure based on new agent discovery
protocols would be time consuming, involve all stakeholders agreeing
on the structure, establishing the structure in a specific

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jurisdiction (which may not be suitable for all parties), and involve
creating the technical infrastructure to support it. The DNS already
has all of these components in place.

2.1.4. Sovereignty

The DNS supports decentralized control while maintaining global
interoperability. Organizations may operate their own authoritative
DNS infrastructure, publish service records independently, and retain
full control over how their services are discovered. This model
enables entities to maintain autonomy over their service exposure and
operational boundaries without reliance on centralized intermediaries
which may not share their same interests.

Proposed alternatives—such as blockchain-based registries, single-
purpose generic top-level domains (gTLDs), or third-party discovery
networks—often introduce opaque governance models, unclear trust
boundaries, and dependencies on external infrastructure. Although
these systems may be described as “decentralized,” they frequently
concentrate control within protocol maintainers, validator networks,
or registry operators, which may not be accountable to the
organizations they serve.

DNS provides a proven and extensible registry model that supports
secure, independent publication of agent metadata. It aligns with
principles of digital sovereignty and operational self-determination,
allowing organizations to participate in agent ecosystems without
relinquishing control over discovery infrastructure.

2.1.5. Commerce

A critical consideration in the design of agent discovery
infrastructure is the potential for commercialization to compromise
integrity. In the absence of established norms or constraints, new
registry-based discovery mechanisms may evolve into visibility-driven
platforms, where agent discoverability is influenced by paid
placement rather than technical merit, trust, or reputation. This
introduces incentives that prioritize commercial interests over
operational reliability and security, undermining the predictability
and neutrality of agent interactions and the free and open Internet
as a whole.

DNS, by contrast, is built on open standards and governed by
transparent, non-commercial processes. It provides mechanisms for
validation and authentication, such as DNSSEC, and certificate
bindings via DANE that are not subject to monetization. The
resolution process is deterministic and not influenced by financial
incentives, preserving the integrity of service discovery.

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Leveraging DNS ensures that agent discovery remains a technical
function grounded in verifiable identity and operational metadata,
rather than a commercial battleground. This supports fair access and
trustworthy interactions across heterogeneous agent ecosystems.

2.1.6. Application

Regardless of how agent discovery is initiated, agent-to-agent
communication ultimately intersects with existing network
infrastructure. Agents may require access to internal services,
external APIs, or shared data repositories, all of which are
typically addressed through conventional networking and resolution
mechanisms. Introducing a separate discovery protocol that fragments
the location and representation of service metadata introduces
architectural complexity and increases the risk of cascading failures
across systems.

Operators would be required to manage multiple layers of resolution
logic, synchronization mechanisms, and failure domains, which
complicates deployment and undermines operational reliability. DNS,
by contrast, is already embedded in the fabric of networked
applications and provides a natural point of integration for
discovery. It enables metadata publication to remain proximate to
the services it describes, reducing latency, simplifying
architecture, and aligning with existing operational models. This
approach supports innovation in agent systems while avoiding brittle
dependencies and minimizing architectural drift.

DNS is predictable for agents to use for the purposes of discovery,
requiring no advanced configurations to consume the service, rather
it is embedded in all pieces of the application stack eliminating the
need to retrofit legacy devices to operate in an agent-to-agent
environment.

2.1.7. Granularity

DNS supports fine-grained control over service discovery through its
hierarchical zone structure and flexible record types. Organizations
may define zones and records at varying levels of specificity,
including per-host, per-service, per-environment (e.g., staging vs.
production), or per geographic region. This granularity enables
precise targeting and segmentation of agent capabilities,
facilitating operational clarity and policy enforcement.

Service Binding (SVCB) records further enhance granularity by
allowing metadata to be associated with individual service endpoints.
This includes transport preferences, supported protocols, and
application-specific parameters. Combined with DNS Service Discovery

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(DNS-SD), these features allow agents to discover services with high
specificity, reducing ambiguity and improving interoperability. The
DNS model supports modular deployment and incremental adoption,
making it well-suited for diverse agent architectures and operational
contexts.

2.1.8. Performance

DNS is well-suited to meet the scale and responsiveness requirements
of agent discovery, where billions of agents may generate trillions
of queries. Its architecture supports high-throughput, low-latency
resolution through mechanisms such as caching, retry logic, and
autom,atic zone distribution to secondary servers. Recursive
resolvers may be further optimized by locally hosting the root zone
[RFC8806], reducing lookup latency and improving fault tolerance.

Additional features such as pre-fetching and negative caching allow
resolvers to anticipate agent behavior and reduce query overhead.
Country code (ccTLD) and Generic Top Level Domain (gTLD) operators
have global infrastructure to support localized resolution and
improve performance for AI-specific applications. These capabilities
enable scalable deployment without requiring protocol redesign or new
infrastructure layers.

Furthermore, DNS-based discovery enables immediate connection
establishment. Once an agent endpoint is resolved, transport
protocols such as QUIC may be used to initiate communication
directly, benefiting from features such as 0-RTT and multiplexed
streams. This eliminates the need for a separate handshake or
negotiation phase for discovery, reducing latency and improving
throughput in high-volume environments. DNS thus provides a
performant and extensible foundation for agent discovery at global
scale.

2.1.9. Lifecycle / Management

DNS provides robust provisioning and lifecycle management
capabilities that align with the dynamic nature of agent-based
systems. Mechanisms such as Incremental Zone Transfer (IXFR) and
Full Zone Transfer (AXFR) allow for rapid propagation of zone updates
across authoritative servers. When backed by database-centric DNS
implementations, zone data may be treated as replicable state,
enabling near-real-time onboarding or decommissioning of agents.

Operational observability is supported through query logging, zone
monitoring, and resolver telemetry, which can be used to track agent
utilization patterns and identify stale or inactive records.

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These lifecycle management capabilities are mature, widely supported,
and compatible with existing operational tooling. They enable high-
churn agent ecosystems to be managed efficiently without requiring
the development of new provisioning, monitoring, or cleanup
protocols.

2.1.10. Trust

In agent discovery, trust encompasses more than identity verification
— it includes confidence in the provenance, behavior, and reliability
of the agents being discovered. The DNS provides a recognizable and
auditable namespace rooted in organizational domains (e.g.,
microsoft.com, openai.com), enabling systems to make informed
decisions about agent interactions based on domain ownership and
established reputational context. This is particularly critical in
AI environments, where agents may initiate autonomous actions or
access sensitive data.

DNS enables organizations to publish agent endpoints under domains
they control, establishing a clear chain of accountability. This
trust model supports cryptographic validation through DNSSEC and
DANE, allowing agents to verify domain ownership and certificate
bindings without manual intervention. By contrast, discovery
mechanisms lacking verifiable lineage introduce significant risk and
complexity, particularly when agents are discovered through opaque or
ungoverned registries.

The BANDAID model builds on the DNS’s trust infrastructure to support
safe and scalable agent discovery. It allows agents to assess the
authenticity and authority of remote endpoints prior to interaction,
reducing the likelihood of misrouting, impersonation, or unauthorized
access. This trust-validation-first approach is foundational to
enabling secure automation in agent ecosystems.

2.1.11. Agent Properties

As agent-to-agent protocols evolve, it is likely more metadata will
need to be signaled in the discovery phase to allow agents to make
more informed decisions. An example of how DNS provides a platform
to facilitate this is below.

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Service Binding (SVCB) records, as defined in [RFC9460], support
extensible key-value parameters that may be registered through the
IANA SVCB Parameter Registry. These parameters can provide agent
systems with operational context prior to session initiation,
enabling informed decisions about whether and how to engage with a
remote agent. It is possible to publish metadata such as input (e.g.
expected token counts) or cost (e.g. cost per token bundle) directly
within DNS records.

This model supports a trust-validation-first approach to agent
interaction, where expectations around resource usage and pricing are
transparently advertised. It reduces the need for handshake-based
negotiation or out-of-band signaling, and allows for deterministic,
cacheable discovery workflows. For instance, by embedding cost-
related metadata in DNS, discovery becomes not only scalable and
performant, but also semantically rich, supporting economically-aware
agent ecosystems without introducing new protocols or registries.

2.1.12. Control

Agent discovery mechanisms must operate within the constraints of
enterprise security policies, regulatory compliance requirements, and
operational boundaries. DNS enables the presentation of distinct DNS
views based on the source of the query. This allows organizations to
expose different sets of agent records to internal versus external
resolvers. For example, internal agents may resolve
_a2a._agents.internal.example.com to discover services not intended
for public exposure, while external agents receive responses only for
_a2a._agents.example.com containing externally authorized endpoints.

Enterprise-grade network controls such as firewalls, Response Policy
Zones (RPZs), and access control lists (ACLs) provide additional
enforcement mechanisms. These controls may restrict outbound DNS
queries to designated resolvers, filter inbound queries to approved
zones, and block unauthorized resolution attempts. This ensures that
agent discovery adheres to organizational boundaries and complies
with internal security policies. For example, an enterprise may
configure its network security to allow internal agents to query only
*.internal.example.com zones, while blocking access to external agent
zones unless explicitly permitted. Similarly, DNS servers may
enforce query logging and rate limiting to detect anomalous behavior
or potential abuse.

Segmented discovery via DNS aligns with compliance requirements
related to data residency, privacy, and access control. By scoping
agent visibility to specific zones and enforcing resolution
boundaries, organizations can ensure that discovery mechanisms
respect jurisdictional constraints, internal governance models, and

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support auditability. Query logs, zone access telemetry, and
resolver behavior can be monitored to verify that agent interactions
conform to policy. This provides a foundation for regulatory
reporting, incident response, and continuous compliance validation
without the need for extensive additional operations that require
more technical staffing or specialized solutions.

2.2. Mechanisms for Successful Agent Communication

The explicit goal of the DNS [RFC1035] is to provide a mechanism for
name resolution, enabling agent discovery without requiring new
protocols, trust anchors, or infrastructure layers. Leveraging DNS
for agent discovery ensures compatibility with existing operational
models, supports incremental deployment, and avoids the risks
associated with experimental or ungoverned discovery mechanisms.

2.2.1. Service Binding Records, aka SVCB

The SVCB resource record as defined in [RFC9460], enables DNS to
convey structured service metadata that facilitates optimized
connection establishment. SVCB records support the advertisement of
protocol identifiers (via ALPN), transport parameters (e.g., port
numbers), endpoint hints (e.g., IP addresses), and extensible key-
value attributes. These capabilities are particularly relevant for
agent-to-agent communication, where protocol negotiation and metadata
exchange must occur without human intervention.

In the context of BANDAID, SVCB records are used to publish agent-
specific service endpoints under structured leaf zones (e.g.,
_chat._agents.example.com). These records allow querying agents to
retrieve operational parameters prior to initiating a session,
including supported protocols, privacy features (e.g., Encrypted
Client Hello via ECH), and failover configurations. This eliminates
the need for heuristic-based connection attempts and reduces round-
trip latency.

SVCB records also support protocol agility and privacy-preserving
features. For example, agents may advertise support for QUIC,
HTTP/3, or custom agent-to-agent protocols via ALPN declarations.
Operators may specify alternate endpoints or migrate services across
domains without relying on CNAME indirection, improving performance
and reducing DNS resolution complexity.

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When paired with attribute leaf zones and custom SVCB parameters,
this mechanism enables fine-grained discovery of agent capabilities.
For instance, an agent querying _a2a._agents.example.com may receive
an SVCB record indicating supported modalities (e.g., chat, image-to-
text), expected input formats, and cost-related metadata (e.g., token
pricing). This structured discovery model supports deterministic,
cacheable, and semantically rich interactions between agents.

2.2.2. DNS Security Extensions, aka DNSSEC

DNSSEC as defined in [RFC4033], [RFC4034], and [RFC4035], enables
resolvers and clients to verify that a response originates from an
authoritative source (authenticity) and DNS data has not been
modified in transit (data integrity). In the context of BANDAID,
DNSSEC serves as a foundational trust mechanism for agent discovery.
By signing agent-related resource records—such as SVCB, TXT, or
custom metadata—organizations can ensure that querying agents receive
authentic and tamper-proof information. This is particularly
critical for agent-to-agent communication, where autonomous systems
must make trust decisions without human oversight.

DNSSEC supports the establishment of cryptographic trust anchors via
Delegation Signer (DS) records and facilitates secure delegation of
authority across zone boundaries. This allows organizations to
publish agent metadata under subdomains (e.g.,
_a2a._agents.example.com) while maintaining verifiable control over
the zone hierarchy.

Furthermore, DNSSEC eliminates the need for hardcoded trust lists or
centralized validation services. Agents can validate responses using
the DNSSEC chain of trust, enabling decentralized and scalable trust
verification. This model supports zero-trust architectures and
aligns with modern security principles by minimizing implicit trust
and enforcing explicit validation.

When combined with DANE (DNS-Based Authentication of Named Entities),
DNSSEC enables binding of TLS certificates to DNS names, further
enhancing the authenticity of agent endpoints. This integration
supports secure session initiation and mitigates risks associated
with certificate mis-issuance or man-in-the-middle attacks. The use
of DANE may improve performance and enable automation in the
dynamicism of agent lifecycle.

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2.2.3. DNS Service Discovery, aka DNS-SD

DNS-SD as defined in [RFC6763], extends the capabilities of the
Domain Name System to support service-type-based discovery. Unlike
traditional DNS resolution, which requires prior knowledge of a
specific hostname, DNS-SD enables clients to discover services based
on their functional type (e.g., _http._tcp, _printer._udp) within a
given domain.

In the context of BANDAID, DNS-SD provides a mechanism for AI agents
to discover other agents or services based on declared capabilities
rather than explicit names. For example, an agent may issue a query
for _data-cleaner._a2a._agents.example.com to locate services capable
of performing data sanitization tasks. This type-based discovery
model supports dynamic ecosystems where agent roles and capabilities
may evolve over time.

DNS-SD operates over both multicast DNS (mDNS) and unicast DNS,
allowing for flexible deployment in local networks and globally
scoped domains. In enterprise or cloud environments, unicast DNS-SD
enables structured and policy-compliant discovery across
organizational boundaries. When combined with SVCB records, DNS-SD
allows agents to retrieve detailed service metadata, including
transport preferences, protocol support, and operational parameters.

This model supports federated agent architectures, where multiple
agents may advertise similar capabilities under different domains.
By leveraging DNS-SD, agents can perform capability-based queries and
receive a list of candidate services, each accompanied by structured
metadata for evaluation and selection.

DNS-SD also supports extensibility through TXT records and custom
service naming conventions, enabling organizations to encode
additional attributes relevant to agent interaction (e.g., supported
data formats, authentication requirements, or cost models). These
features make DNS-SD a suitable foundation for scalable,
interoperable, and semantically rich agent discovery workflows.

2.2.4. DNS-Based Authentication of Named Entities, aka DANE

DANE as specified in [RFC6698] and [RFC7671], enables domain owners
to associate Transport Layer Security (TLS) certificates with DNS
names using TLSA resource records. When protected by DNSSEC, these
records provide cryptographically verifiable bindings between domain
names and public keys, allowing clients to authenticate services
without relying solely on external certificate authorities (CAs).

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In the context of BANDAID, DANE enhances the trust model for agent-
to-agent communication by enabling agents to validate the
authenticity of remote endpoints based on domain-controlled
assertions. This is particularly relevant in automated environments
where agents must establish secure sessions without manual
certificate validation or user interaction.

By publishing TLSA records under agent-specific service names (e.g.,
_a2a._tcp.agent.example.com), organizations can declare the expected
certificate fingerprint or public key for a given agent endpoint.
Querying agents can then validate the TLS connection against the DANE
record, ensuring that the certificate presented during session
initiation matches the domain’s published intent.

This mechanism mitigates risks associated with certificate mis-
issuance, man-in-the-middle attacks, and reliance on third-party
trust anchors. It also supports deterministic validation workflows,
which are critical for agents operating in headless or GUI-less
environments where interactive certificate warnings cannot be
resolved.

When combined with DNSSEC, DANE provides a robust, decentralized, and
verifiable trust infrastructure for agent discovery and
communication. It aligns with zero-trust principles by enabling
domain owners to assert and control trust relationships directly
through DNS, without introducing additional registries or validation
services.

2.2.5. Domain Control Validation, aka DCV

DCV refers to the process by which an entity demonstrates
authoritative control over a DNS domain. As described in draft-ietf-
dnsop-domain-verification-techniques, DNS-based DCV typically
involves the placement of a DNS record—most commonly a TXT
record—containing a challenge token or assertion at a designated
location within the domain. This record is then queried by an
Application Service Provider (ASP) to confirm control.

In the context of BANDAID, DCV provides a mechanism for agents to
assert delegated authority on behalf of a domain. For example, an
organization may publish a TXT record under a structured leaf zone
(e.g., _agent-roles._a2a._agents.example.com) containing metadata
such as:

ai-role=data-cleaner; crm=salesforce; access=readonly

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This record signals that a specific agent is authorized to perform
scoped operations under the domain's authority. When protected by
DNSSEC, such assertions become cryptographically verifiable,
mitigating risks of spoofing or unauthorized delegation.

DCV within BANDAID supports both ephemeral and persistent validation
models. Ephemeral validation may be used for short-lived agent
credentials or session-based delegation, while persistent records
enable long-term authorization signaling. TTL and expiration
considerations, as discussed in the draft, are critical to ensuring
that validation records do not persist beyond their intended scope.

Furthermore, BANDAID encourages the use of application-specific
naming conventions and token formats to avoid service confusion and
collision. Validation records should be scoped to the intended
service and include unguessable tokens or structured metadata to
prevent unauthorized reuse across federated agent ecosystems.

2.2.6. Service Resilience

The DNS architecture is inherently resilient due to its distributed,
hierarchical design. Authoritative zones are replicated across
multiple servers, and recursive resolvers implement caching, retry
logic, and failover mechanisms to ensure continuity of resolution.
Failover, anycast, and replication continue to add resiliency and
redundancy provided through the DNS.

This fault-tolerant model supports agent discovery even in the
presence of partial network outages, denial-of-service conditions, or
upstream failures. Unlike centralized registries or proprietary
APIs, DNS does not rely on a single point of availability, making it
suitable for high-availability agent ecosystems operating across
diverse network environments.

2.2.7. Observability, Auditability

DNS provides built-in observability through query logging, resolver
telemetry, and zone monitoring. These features enable operators to
track agent discovery patterns, detect anomalous behavior, and
perform forensic analysis of agent interactions. This auditability
is critical in regulated environments where agent actions must be
attributable and verifiable, and where discovery mechanisms must
align with enterprise governance models.

Logs may be used to validate compliance with access policies,
identify stale or misconfigured records, support incident response
workflows, and/or be used in lifecycle management of unused or
oversubscribed agents.

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2.2.8. Interoperability

BANDAID is designed to be agnostic to agent implementation
frameworks. Whether agents are built using open-source libraries,
proprietary orchestration platforms, or custom runtimes, DNS-based
discovery provides a common substrate for metadata publication and
retrieval. This interoperability ensures that agents operating under
different protocols, vendors, or administrative domains can
participate in shared discovery workflows without requiring protocol
translation or framework-specific integration. DNS’s ubiquity across
operating systems and network stacks further reinforces its
suitability as a universal discovery layer.

2.2.9. Multitenancy, Federation

DNS’s hierarchical namespace supports multi-tenant and federated
discovery models. Organizations may delegate subdomains to tenants
(e.g., customer1._agents.vendor.com) or publish agent metadata under
federated zones (e.g., region1._a2a.example.org). This enables
scoped discovery, policy enforcement, and operational isolation
across tenants, departments, or geographic regions. Combined with
DNSSEC and access controls, this model supports secure delegation and
trust signaling in complex agent ecosystems, including SaaS platforms
and cross-organizational collaborations.

2.3. Architecture

2.3.1. Example Communication

Agent (org1) wants to find other agents provided by another entity
(org2) and discover/verify capabilities

DNS SVCB Query ┌────────┐ _a2a._agents.example.com ┌────────┐
┌────────┐ │AI
Agent├─────────────────────────────►│Resolver├───────────►│Auth DNS│
│ (ORG1) │ ◄────────────────────────────┤ (ORG1) │◄─────┬─────┤
(ORG2) │ └────────┘ └────────┘ │ └────────┘ │
┌─────────────────────────────────────────────────┴─────────────┐
│_a2a._aiagent.org2.com. 3600 IN SVCB 1 ai-index-svc.org2.com. (│ │
alpn="a2a" │ │ port=443 │ │ ipv4hint=192.0.2.1 │ │
ipv6hint=2001:db8::1 │ │) │
└───────────────────────────────────────────────────────────────┘

2.3.2. Example Record

_a2a._aiagent.org2.com. 3600 IN SVCB 1 ai-index-svc.org2.com. (
alpn="a2a" port=443 ipv4hint=192.0.2.1 ipv6hint=2001:db8::1 )

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_a2a._aiagent.example.com.: The service name, following the SVCB
naming convention (_service._agents.example.com). 3600: TTL (Time to
Live) in seconds. IN SVCB: The record type. 1: SVCB priority. 0 is
for alias mode; 1+ is for service mode. ai-index-svc.org2.com.: The
target name of the service. alpn="a2a": Specifies the ALPN protocol
identifier. This is where your custom protocol is declared.
port=443: The port on which the service is available. ipv4hint and
ipv6hint: Optional hints for clients to connect directly.

2.3.3. Example Use Cases

A user instructs their internal agent to “clean up Salesforce
contacts based on this email.” The agent must discover
Salesforce’s authorized agents, validate its own delegation to act
on behalf of the enterprise, and initiate a secure session.
BANDAID enables this by publishing agent endpoints and roles under
DNS zones controlled by each organization.

A research consortium deploys agents across multiple institutions.
Each institution publishes its agents under its own domain (e.g.,
_a2a._agents.universityA.edu), allowing collaborators to discover
services based on capability (e.g., _data-
annotator._a2a.universityB.edu) while respecting institutional
boundaries and trust models.

A SaaS provider hosts agents for multiple customers. Each
customer’s agents are published under tenant-specific zones (e.g.,
customer1._agents.saas.com), enabling scoped discovery and policy
enforcement. BANDAID supports this model through hierarchical
zone delegation and metadata-rich SVCB records.

Lightweight agents deployed on mobile or edge devices require low-
latency, cacheable discovery mechanisms. DNS’s distributed
architecture and support for SVCB hints (e.g., IP addresses,
preferred protocols) enable efficient resolution and connection
bootstrapping in constrained environments.

In regulated industries, agents must operate within jurisdictional
boundaries and maintain audit trails of interactions. DNS
supports geographic scoping via ccTLDs and split-horizon
configurations, while query logging and DNSSEC provide
observability and integrity guarantees.

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3. BANDAID Overview

The BANDAID model is designed for incremental and non-disruptive
deployment within existing DNS infrastructure. It introduces no new
DNS message formats, opcodes, response codes, or resource record
types. Instead, it defines a structured namespace convention and
usage profile for existing record types... primarily SVCB, TXT, and
TLSA all within designated leaf zones (e.g.,
_a2a._agents.example.com).

Organizations may adopt BANDAID by publishing agent metadata under
delegated subdomains, leveraging DNSSEC for integrity and
authenticity, and optionally implementing Domain Control Validation
(DCV) to signal delegated authority. These zones may be exposed
selectively via split-horizon DNS, enabling differentiated discovery
views for internal and external agents. No changes are required to
recursive or authoritative DNS server implementations beyond standard
support for DNSSEC and SVCB.

This model supports opt-in adoption, allowing agent operators to
publish discovery metadata without coordination with external
registries or protocol maintainers. It is compatible with existing
DNS tooling, including zone provisioning systems, monitoring
platforms, and resolver configurations. BANDAID is therefore
suitable for deployment across enterprise, cloud, and federated
environments, and may coexist with other discovery mechanisms without
conflict.

3.1. Zone and Other Requirements

3.1.1. Delegation and Chain of Trust

An external authoritative zone used for the purposes of BANDAID MUST
use DNSSEC [RFC4033]. The BANDAID external zone MUST establish a
complete chain of trust to a publicly recognized trust anchor. For
zones delegated from a public parent, DS records MUST be present and
maintained at the parent zone. DS digests MUST use SHA-256 (Digest
Type 2) as specified in [RFC4509]; SHA-1 (Digest Type 1) MUST NOT be
used. Where feasible, automation of DS maintenance SHOULD be
performed using CDS and CDNSKEY as specified in [RFC7344] and
operationalized per [RFC8078].

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3.1.2. Algorithms and Parameters

Authoritative signers for the BANDAID External Zone MUST use DNSSEC
algorithms and key sizes consistent with current implementation and
usage guidance in [RFC8624]. Implementations SHOULD prefer
elliptic-curve or EdDSA algorithms for efficiency and security,
specifically ECDSA P-256 (Algorithm 13; [RFC6605]) or Ed25519
(Algorithm 15; [RFC8080]). Zones MUST NOT rely on RSA/SHA-1
signatures. If RSA is used for transitional reasons, key sizes
SHOULD be ≥ 2048 bits and migration to ECDSA or EdDSA SHOULD be
planned.

Separation of roles between a Key-Signing Key (KSK) and a
Zone-Signing Key (ZSK) is RECOMMENDED for operational agility,
consistent with practices in [RFC6781]. Private keys SHOULD be
protected by appropriate controls (e.g., HSMs or equivalent)
commensurate with organizational risk.

3.1.3. Authenticated Denial of Existence

The BANDAID External Zone MUST provide authenticated denial of
existence. NSEC3 [RFC5155] is RECOMMENDED to mitigate trivial zone
enumeration for zones where record names or labels might reveal
sensitive information. If NSEC3 is used, the number of iterations
SHOULD be kept modest to balance CPU cost for signers and validators,
per guidance in [RFC6781]. Use of NSEC with White Lies is OPTIONAL
where operationally justified.

3.1.4. Signature Validity

Signature validity windows MUST be chosen to balance cache efficiency
and replay risk. In general, a signature lifetime on the order of
days to a small number of weeks is RECOMMENDED, with staggered
resigning to avoid mass expiration events [RFC6781]. Resource Record
TTLs MUST be set to values that support timely updates to BANDAID
capability data while allowing effective caching; operational
defaults SHOULD be validated against change frequency. Negative
caching behavior MUST follow [RFC2308].

3.1.5. Key Rollover

Zones MUST support planned key rollovers and emergency key
replacement consistent with the procedures in [RFC6781].
Pre-publication and double-signature techniques SHOULD be used to
minimize validation failures during ZSK and KSK rollovers. Parent DS
changes SHOULD be orchestrated using CDS/CDNSKEY signaling
[RFC7344][RFC8078]. Post-compromise recovery procedures MUST be
documented, including revocation, re-signing, and DS replacement

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timelines.

3.1.6. Transport and Message Size

Because DNSSEC increases response sizes, authoritative servers for
the BANDAID External Zone MUST implement EDNS(0) per [RFC6891] and
MUST support TCP fallback for queries per [RFC7766]. Authoritative
operators SHOULD configure UDP response sizing to minimize IP
fragmentation risk and SHOULD ensure that large responses (e.g.,
DNSKEY, NSEC3 chains) remain retrievable via TCP.

3.1.7. Transfer and Integrity

When secondary authoritative servers are used, zone transfers MUST be
authenticated and protected with TSIG [RFC2845]. Use of DNS NOTIFY
[RFC1996] and incremental transfer (IXFR; [RFC5936]) is RECOMMENDED
to reduce propagation latency and bandwidth. To provide at-rest
integrity verification between primaries and secondaries, publishing
a ZONEMD record is RECOMMENDED where supported [RFC8976].

3.1.8. Monitoring

Operators MUST monitor DNSSEC validity from multiple vantage points
to detect stale signatures, DS/DNSKEY mismatches, and other
validation failures. Alarms SHOULD be configured for impending
signature expiration, key compromise indicators, and DS
inconsistencies. Signing infrastructure SHOULD be tested under load
and failure scenarios consistent with the scalability requirements of
this specification.

3.1.9. Abuse Resistance

Authoritative servers for the BANDAID External Zone SHOULD implement
DNS Cookies [RFC7873][RFC9018] to reduce off-path spoofing and
amplification risks. Operators SHOULD follow best practices to limit
amplification and to shape responses under attack, consistent with
maintaining DNSSEC validity.

3.1.10. BANDAID Records

All BANDAID-specific discovery records (e.g., SRV [RFC2782], SVCB/
HTTPS [RFC9460], TXT/URI [RFC7553] used for capability descriptors,
and any BANDAID-defined RRTypes) MUST be signed and published in the
BANDAID External Zone. Where BANDAID endpoints rely on TLS,
publication of DANE TLSA records SHOULD be used to bind endpoint
certificates to DNSSEC-validated names [RFC6698][RFC7671]. Resolver
behavior consuming BANDAID data MUST treat DNSSEC-bogus responses as
failures and MUST NOT act on unsigned or invalidly signed discovery

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data.

3.1.11. Performance Optimization(s)

The discovery namespace for BANDAID SHOULD be structured to minimize
query depth, RRset size, and update blast radius. To that end,
implementers SHOULD allocate per-service, per-agent leaf names and
avoid aggregating high-cardinality data under a single owner name. A
deterministic mapping (e.g., a stable hash of an Agent Identifier) to
leaf labels SHOULD be used to support sharding and parallel
administration. Where cardinality requires, sub-zones MAY be
delegated (zone cuts) to distribute authority and update load.

Each agent service endpoint SHOULD be published using SVCB in
ServiceMode (or HTTPS RR for HTTPS endpoints) to convey connection
parameters and capability locators with a single lookup [RFC9460].
SVCB “address hints” (ipv4hint, ipv6hint) SHOULD be used to reduce A/
AAAA follow-up queries; resolvers MAY still validate final addresses
via canonical resolution. Where human-friendly names are required,
SVCB AliasMode (priority 0) MAY be used to map from a stable alias to
a hashed leaf, avoiding record duplication while preserving cache
locality.

Authoritative servers MUST support EDNS(0) [RFC6891] and TCP fallback
[RFC7766]. Operators SHOULD target response sizes that avoid IP
fragmentation on common paths (e.g., ≤1232 bytes on IPv6), preferring
compression and layered indirection over oversized RRsets. TTLs MUST
be chosen to reflect the volatility of capability data; index/
indirection records may use longer TTLs than frequently changing
endpoint or capability descriptors. Negative caching MUST conform to
[RFC2308]. When high update rates are expected, IXFR and NOTIFY
SHOULD be used to reduce propagation latency.

Resolvers and authoritative operators SHOULD take advantage of SVCB’s
ALPN, port, and (for HTTPS) ECH parameters to enable connection
pre-establishment and reduce round-trips, subject to client policy
and security posture [RFC9460]. Where privacy policies prohibit
client geolocation, EDNS Client Subnet SHOULD NOT be relied upon for
performance.

A representative naming pattern is shown below; the exact label order
is deployment-specific, but the leaf per service, per agent rule
applies:

``` ; Hashed, per-agent, per-service leaf
a4k2f9._mcp._bandaid.example.org. 600 IN SVCB 1 svc-
a4k2f9.example.org. alpn="h2,h3" port=443 ipv6hint=2001:db8::5
ipv4hint=192.0.2.5

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; Optional alias for a friendlier owner name
billing._mcp._bandaid.example.org. 300 IN SVCB 0
a4k2f9._mcp._bandaid.example.org. ```

3.1.12. Customization(s)

BANDAID deployments MAY define additional SVCB parameters
(SvcParamKeys) to convey agent-specific capability metadata, provided
that interoperability safeguards in [RFC9460] are observed. During
experimentation, unregistered keys MUST use the numeric keyNNNNN
presentation form, and any client behavior that depends on them MUST
be gated via the mandatory SvcParam to ensure downgrade safety. This
specification defines the following provisional SvcParamKeys for
BANDAID (names are illustrative; production deployments MUST register
through IANA per [RFC9460] or use keyNNNNN until standardized):

cap — a capability descriptor locator or inline identifier (e.g.,
a URN or compact JSON-Ref) that identifies the agent’s advertised
capability schema/version. cap-sha256 — a base64url-encoded
SHA-256 digest of the canonical capability descriptor to support
integrity checks and cache revalidation. bap — a comma-separated
list of BANDAID Application Protocols and versions understood by
the endpoint (e.g., bap="a2a/1,mcp/1,acp/2"). This is distinct
from transport-level alpn. policy — a URI or URN identifying a
policy bundle applicable to this agent (e.g., jurisdiction, data
handling class) for client-side selection. realm — an opaque token
for multi-tenant scoping or authz realm selection during protocol
bootstrapping.

Clients that require any of these parameters MUST verify their
presence via the mandatory key; otherwise, the SVCB record MUST be
ignored. Example:

Single-RRTYPE publication with custom params (experimental keys
shown) a4k2f9._mcp._bandaid.example.org. 600 IN SVCB 1 svc-
a4k2f9.example.org. alpn="h2" port=443 ipv4hint=192.0.2.5
mandatory=alpn,port,key65001,key65002,key65010
key65001="cap=urn:cap:example:mcp:invoice.v1" key65002="cap-
sha256=yvZ0n7q8bE2gYkz8m1j1s0yQG0mC2F6qj3b9pVb6Gk0"
key65010="bap=a2a/1,mcp/1" Where endpoints are HTTPS, the HTTPS RR
variant SHOULD be used to co-locate transport parameters such as ech
with capability metadata; otherwise, generic SVCB MAY be used.
Future standardization SHOULD define the exact syntax (e.g., ABNF)
and registry policy for these keys, including error handling for
malformed or conflicting parameters. Until registration is complete,
deployments MUST treat unknown keyNNNNN parameters as opaque and MUST
NOT infer semantics without out-of-band agreement.

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4. Implementation Guidance

4.1. AI Operators

4.1.1. Separation of Roles

Operators MUST separate authoritative servers for BANDAID zones from
recursive resolvers to prevent cache poisoning and reduce operational
coupling. Authoritative servers MUST NOT perform recursion.
Recursive resolvers SHOULD be deployed close to query sources (e.g.,
within organizational networks or edge PoPs) to minimize latency and
reduce upstream load.

4.1.2. Local Root Zone Copy

Recursive resolvers serving BANDAID traffic SHOULD maintain a local
copy of the root zone as specified in [RFC8806]. This eliminates
dependency on external root servers for priming queries, reduces
resolution latency, and improves resilience during partial Internet
outages or denial-of-service events targeting root infrastructure.

4.1.3. Aggressive Caching and Prefetch

Resolvers MUST implement RFC-compliant caching and SHOULD enable the
aggressive use of DNSSEC-validated cache to synthesize negative
answers from NSEC/NSEC3 and reduce upstream lookups, consistent with
[RFC8198]. This behavior improves latency, lowers authoritative
load, and can mitigate certain attack patterns by answering within
validated non-existence ranges.

Resolvers SHOULD implement serve-stale as specified in [RFC8767].
When authoritative servers are unreachable or fail to refresh data, a
resolver MAY return expired records from its cache to preserve
availability, subject to policy caps on staleness. [RFC8767] updates
the TTL semantics to allow use beyond expiration under these
exceptional conditions and RECOMMENDS capping staleness on the order
of days, with a typical cap of 7 days. When serving stale data, the
TTL in the response MUST be set to a value greater than zero (with 30
seconds RECOMMENDED) so clients and intermediaries do not cache a
zero-TTL response indefinitely.

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Resolvers implementing serve-stale SHOULD follow the timer guidance
in [RFC8767]: continue background refresh (“stale-while-revalidate”),
bound total resolution work with a query-resolution timer, avoid
excessive re-tries with a failure-recheck timer (no more frequently
than ~30 seconds is RECOMMENDED), and ensure client responsiveness
with a client-response timer (on the order of ~1.8 seconds is
RECOMMENDED). These controls balance resiliency with freshness and
protect upstream authorities during outages or attack conditions.

Operators MUST consider DNSSEC interactions when serving stale data.
Stale answers can increase the likelihood that signatures are outside
their validity windows; implementations MUST NOT misrepresent
validation status (e.g., AD bit handling MUST follow DNSSEC semantics
where the bit is only set if all relevant RRsets are
cryptographically verified according to local policy).

Prefetch of popular BANDAID names SHOULD be used to keep caches warm,
and negative caching MUST follow [RFC2308] to avoid unnecessary
upstream traffic during flaps. Where serve-stale is enabled,
operators SHOULD monitor stale-answer rates and staleness
distribution to ensure that policy caps and refresh behavior meet
availability and freshness objectives.

4.1.4. EDNS(0) Transport Resilience

All servers MUST support EDNS(0) [RFC6891] and TCP fallback [RFC7766]
to accommodate DNSSEC and SVCB responses that exceed traditional UDP
size limits. Operators SHOULD configure UDP response sizing to avoid
IP fragmentation (e.g., ≤1232 bytes for IPv6 paths) and SHOULD
monitor truncation rates to detect misconfigurations or path MTU
issues.\

4.1.5. Load Distribution

Authoritative servers for BANDAID zones SHOULD be deployed using IP
anycast to provide global reachability, load balancing, and DDoS
resilience. Recursive resolvers SHOULD be deployed in a
geographically distributed manner to minimize latency for agent
queries and to provide failover during regional outages.

4.1.6. Monitoring and Telemetry

Operators MUST implement continuous monitoring of query latency,
cache hit ratios, DNSSEC validation success rates, and transport
fallback events. Alarms SHOULD be configured for anomalies such as
sudden TTL exhaustion, signature expiration, or upstream
unreachability. Logging MUST respect privacy and regulatory
constraints while providing sufficient detail for operational

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troubleshooting and compliance audits.

4.1.7. Encrypted Resolver Steering (Informative)

AI clients and operators MAY implement Encrypted DNS Server
Redirection (EDSR) to permit an encrypted resolver to redirect a
client to another encrypted resolver for performance, locality, or
policy reasons Any acceptance of redirection MUST follow the
verified-discovery model of DDR [RFC9462], including validation of
the designated relationship and TLS authentication of the target
resolver. If redirection validation fails or exceeds a single hop,
clients MUST continue to use the original resolver configuration.
When available, network-designated resolvers provisioned via DNR
[RFC9463] take precedence over unsolicited redirection unless local
policy dictates otherwise. EDSR is currently an Internet-Draft and
is referenced as an OPTIONAL extension.

4.2. AI Consumers

4.2.1. DNS-Based Service Discovery

DNS-Based Service Discovery AI clients that consume BANDAID discovery
data MUST implement DNS-based service discovery consistent with
[RFC6763] and [RFC9460]. Clients SHOULD query for SVCB or HTTPS
records at well-defined service labels (e.g.,
_mcp._bandaid.example.org.) and interpret alpn, port, and custom
SvcParams as specified in this document. Where multiple priorities
are returned, clients MUST honor the SVCB priority and weight
semantics for selection and failover. Clients MUST validate DNSSEC
signatures for all discovery responses and MUST NOT act on unsigned
or bogus data.

Clients SHOULD implement caching consistent with TTLs and negative
caching rules in [RFC2308]. Prefetching of high-traffic names MAY be
used to reduce latency, provided that it does not violate policy or
privacy constraints. Clients MUST support EDNS(0) and TCP fallback
to handle large responses.

4.2.2. Communication Failure / Retry

When a discovered agent endpoint is unreachable, clients MUST
implement retry logic that respects exponential backoff and avoids
synchronized retry storms. Clients SHOULD attempt alternate SVCB
targets in priority order before declaring failure. Where
serve-stale responses are received, clients MUST treat them as
advisory and MUST NOT assume freshness beyond the TTL indicated in
the response. Clients SHOULD log stale usage for observability and
compliance.

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4.2.3. Domain Control Validation

To prevent impersonation and unauthorized data access, BANDAID
deployments MUST support Domain Control Validation (DCV) using DNS.
This mechanism allows application owners to verify that a requesting
service is authorized to act on behalf of a domain (e.g., “AI, sync
all customer contacts from my approved CRM for acme.org”). DCV MUST
follow a challenge-response model where the domain owner publishes a
cryptographically strong token in a DNS TXT record under a
well-defined label (e.g., _bandaid-challenge.acme.org.). The token
MUST be bound to the requesting service identity and have a bounded
validity period. Clients performing DCV MUST validate the token
against the expected value and expiration before granting delegated
access. Tokens SHOULD be single-use and MUST be removed from DNS
after successful validation. All DCV interactions MUST occur over
DNSSEC-validated channels to prevent spoofing or downgrade attacks.

4.3. AI Developers

4.3.1. Publishing Schema

Publishers SHOULD expose per-service discovery records using SVCB (or
HTTPS for HTTP origins) at stable, well-scoped owner names (e.g.,
agent-id._mcp._bandaid.example.org.). SVCB ServiceMode conveys
connection parameters and capability locators in a single round trip;
AliasMode MAY be used to map a friendly name to a hashed leaf for
sharding without duplicating RRSets. Initial connection parameter
keys (alpn, port, address hints) and the mandatory key MUST be
honored by clients. [RFC9460]

Minimal example:

; ServiceMode SVCB for an MCP-capable agent
a4k2f9._mcp._bandaid.example.org. 600 IN SVCB 1 svc-
a4k2f9.example.net. alpn="h2,h3" port=443 ipv6hint=2001:db8::5
ipv4hint=192.0.2.5 mandatory=alpn,port

SVCB/HTTPS semantics and SvcParam processing MUST follow [RFC9460] to
ensure interop and correct fallback.

4.3.2. TTLs, Update Agility

Publishers SHOULD assign longer TTLs to relatively static indirection
records (aliases, stable service labels) and shorter TTLs to volatile
endpoint/capability records to balance cache efficiency with rollout
safety. Consumers will apply negative caching per [RFC2308], so
publishers SHOULD avoid unnecessary NXDOMAIN flaps during deployments
(e.g., prefer blue/green leaves over in-place deletions).

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4.3.3. Capability Retrieval

When capability metadata is referenced via URI from SVCB/HTTPS,
retrieval MUST occur over authenticated, confidential channels.
Publishers SHOULD offer TLS 1.3 and MAY bind endpoint identity via
DANE TLSA where resolvers validate DNSSEC; otherwise, WebPKI
validation applies. Operational guidance for DANE usage (certificate
usage selections, rollover) SHOULD follow [RFC7671] [RFC8446]
[RFC6698]

Where using HTTPS RRs, publishers MAY advertise the ech SvcParam to
enable Encrypted Client Hello for privacy; client/server behavior and
key distribution MUST follow the semantics described in [RFC9460] for
the ech parameter.

4.3.4. Example DCV Flow

Example DCV Flow (Normative Sketch)

* The relying service issues a DCV challenge with a nonce bound to
its identity and an expiration time.

* The domain owner publishes the nonce at _bandaid-challenge.domain.
as a TXT RR until validation completes.

* The verifier performs a DNSSEC-validated TXT query and compares
the presented nonce and binding; on success, access is granted and
the TXT is removed.

need a sketch for how this looks

4.3.5. Example Zonefile

``` $ORIGIN example.org. $TTL 3600

; -------------------------------------------------------------------
--- ; SOA / NS ; ----------------------------------------------------
------------------ @ IN SOA ns1.example.org. hostmaster.example.org.
( 2025091901 ; serial (YYYYMMDDnn) 7200 ; refresh 1800 ; retry
1209600 ; expire 3600 ) ; minimum IN NS ns1.example.org. IN NS
ns2.example.org.

ns1 IN A 192.0.2.53 ns1 IN AAAA 2001:db8::53 ns2 IN A 192.0.2.54 ns2
IN AAAA 2001:db8::54

; -------------------------------------------------------------------
--- ; BANDAID discovery (MCP example): per-service, per-agent leaf ;
- Leaf is a stable mapping from AgentID -> label (e.g. hashed). ; -

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Use SVCB ServiceMode (priority > 0) to bind connection parameters. ;
---------------------------------------------------------------------
-

; AliasMode to keep a friendly name stable even if the leaf changes
billing._mcp._bandaid 300 IN SVCB 0 a4k2f9._mcp._bandaid.example.org.

; Leaf per agent/service (ServiceMode). Shorter TTL for agility.
a4k2f9._mcp._bandaid 600 IN SVCB 1 svc-a4k2f9.example.net. \
alpn="h2,h3" \ port=443 \ ipv4hint=192.0.2.5 \ ipv6hint=2001:db8::5 \
mandatory=alpn,port

; (Optional) Another service face for the same agent (A2A)
a4k2f9._a2a._bandaid 600 IN SVCB 1 svc-a4k2f9.example.net. \
alpn="h2" port=8443 \ mandatory=alpn,port

; (Optional) HTTPS RR at apex for web-style consumers of BANDAID
metadata @ 900 IN HTTPS 1 web-gw.example.net. \ alpn="h2,h3" port=443

; -------------------------------------------------------------------
--- ; Capability / policy signaling via SVCB custom keys
(experimental) ; Use numeric keyNNNNN until you register IANA
SvcParamKeys. ; Gate client requirements with "mandatory". ; --------
-------------------------------------------------------------- ;
Example: reference a capability descriptor and advertise supported
app protocols. ; NOTE: Values and key numbers are illustrative.

a4k2f9._mcp._bandaid 600 IN SVCB 1 svc-a4k2f9.example.net. \
alpn="h2,h3" port=443 \ mandatory=alpn,port,key65001,key65010 \
key65001="cap=urn:cap:example:mcp:invoice.v1" \
key65010="bap=a2a/1,mcp/1"

; -------------------------------------------------------------------
--- ; Domain Control Validation (DCV) for BANDAID authorization ;
Publish a short-lived token to prove control over example.org. ;
Remove after successful validation. Resolver MUST DNSSEC-validate. ;
---------------------------------------------------------------------
- _bandaid-challenge 300 IN TXT "bnd-req=svc:crm-
sync@vendor.example;nonce=3Qz6l8pA;exp=2025-09-19T06:00:00Z"

; -------------------------------------------------------------------
--- ; Optional DANE TLSA for the service endpoint used above. ;
Owner: _<port>._tcp.<endpoint-FQDN> ; Usage 3 (DANE-EE), Selector 1
(SPKI), Match 1 (SHA-256) ; Replace the hash with the actual SPKI
hash of the leaf certificate. ; -------------------------------------
--------------------------------- _443._tcp.svc-a4k2f9.example.net.
1800 IN TLSA 3 1 1 (
0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789AB )

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; -------------------------------------------------------------------
--- ; (Optional) Address records for the service endpoint, if hosted
in-zone ; If hosted out-of-zone (example.net), these will live there
instead. ; ----------------------------------------------------------
------------ svc-a4k2f9 900 IN A 192.0.2.5 svc-a4k2f9 900 IN AAAA
2001:db8::5 web-gw 900 IN A 192.0.2.80 web-gw 900 IN AAAA
2001:db8::80 ```

4.3.5.1. How to use this zonefile

* Adjust TTLs for agility vs. cache efficiency. Use longer TTLs on
indirection (aliases), shorter TTLs on volatile leaves and DCV.
This aligns with DNS caching behavior and negative caching rules
[RFC2308].

* Follow SVCB/HTTPS semantics. Clients must honor SvcPriority,
AliasMode (priority 0), and ServiceMode parameters, including
mandatory, alpn, port, and address hints per [RFC9460].

* DCV token flow. Issue a time-bounded token at _bandaid-
challenge.domain and require DNSSEC-validated retrieval (pattern
analogous to ACME’s DNS-01 in [RFC8555]). Remove on success.

* Bind transport to DNS with DANE (optional). If your relying
parties validate DNSSEC, publish TLSA to bind the endpoint’s cert/
key, using the operational guidance in [RFC7671] (TLSA record
format in [RFC6698]).

* Sign the zone. This file is pre-signing. Sign with DNSSEC
(DNSKEY/DS/RRSIG, etc.) before deployment; validators must treat
unsigned/bogus discovery data as a failure (per your earlier
spec). See DNSSEC core specs [RFC4033], [RFC4034], [RFC4035] and
operational guidance.

4.3.5.2. Why these records

* SVCB/HTTPS concentrate connection metadata and allow aliasing at
apex and service labels, reducing round trips and enabling
policy-gated params via mandatory.

* Per-service, per-agent leaves avoid oversized RRsets and allow
parallel administration/sharding while keeping alias names stable.
This follows performance guidance in SVCB and your BANDAID perf
section.

* DCV via TXT mirrors a well-understood, automated control-proof
pattern [RFC8555] that fits BANDAID authorization workflows.

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* DANE TLSA optionally removes reliance on external PKI anchors for
endpoint auth where DNSSEC is deployed [RFC6698], with deployment
rules in [RFC7671].

5. Conclusion

The discovery of AI agents at Internet scale introduces requirements
for autonomy, security, resilience, and interoperability that cannot
be met by ad-hoc or centralized mechanisms. Organizations must
advertise capabilities in a manner that is globally unique,
cryptographically verifiable, and operationally scalable, while
preserving compliance with regulatory and sovereignty constraints.
The solution space must account for dynamic lifecycles, selective
disclosure, and the ability to integrate with existing infrastructure
without introducing new trust anchors or governance choke points.

This document defines BANDAID as a DNS-based discovery framework that
leverages the global DNS namespace, DNSSEC for integrity and
authenticity, and SVCB/HTTPS records for structured capability
advertisement. By building on widely deployed protocols and
operational practices, BANDAID provides a predictable entry point for
agent discovery, supports hierarchical delegation for organizational
autonomy, and enables secure, low-latency resolution at scale.
Extensions such as custom SvcParams, DNS-based domain control
validation, and optional DANE bindings further strengthen trust and
interoperability.

Future work includes standardizing capability schemas, formalizing
SvcParam registries for BANDAID metadata, and defining
privacy-preserving query mechanisms (like authoritative DOT/H/Q). By
aligning with existing Internet standards and operational best
practices, BANDAID offers a path to interoperable, secure, and
resilient AI agent discovery without reinventing the foundational
layers of the Internet.

5.1. Future Work & Unaddressed Portions

Index versus agents publishing their updates, etc. Unresolved in the
use case of it being better to have an index which is a list of all
agents an org owns, or allow records within the zone to be the record
of truth.

For example, a company may only have a few external agents available
for use, and if the IETF standardizes 'types' of AI agents, then
perhaps _chat._ai.domain.com or _img2txt._ai.domain.com etc are all
different SVCB records.

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6. Security Considerations

To add: Lookalikes, takedowns, misbehaving agents, compliance,
privacy

7. IANA Considerations

IANA are to consider registering an underscored attribute leaf as
part of [RFC8552] for BANDAID.

IANA are to consider designating custom key-value pairs for SVCB
parameters to facilitate agent-to-agent application discovery,
potentially for cost optimization (token input counts, costs per
token bundle, etc.)

8. References

8.1. 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>.

[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>.

8.2. Informative References

[I-D.draft-mozley-aidiscovery]
Mozley, J., Williams, N., Sarikaya, B., and R. Schott, "AI
Agent Discovery (AID) Problem Statement", Work in
Progress, Internet-Draft, draft-mozley-aidiscovery-00, 15
October 2025, <https://datatracker.ietf.org/doc/html/
draft-mozley-aidiscovery-00>.

[I-D.draft-rosenberg-ai-protocols]
Rosenberg, J. and C. F. Jennings, "Framework, Use Cases
and Requirements for AI Agent Protocols", Work in
Progress, Internet-Draft, draft-rosenberg-ai-protocols-00,
5 May 2025, <https://datatracker.ietf.org/doc/html/draft-
rosenberg-ai-protocols-00>.

[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
November 1987, <https://www.rfc-editor.org/rfc/rfc1035>.

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[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>.

[RFC2308] Andrews, M., "Negative Caching of DNS Queries (DNS
NCACHE)", RFC 2308, DOI 10.17487/RFC2308, March 1998,
<https://www.rfc-editor.org/rfc/rfc2308>.

[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782,
DOI 10.17487/RFC2782, February 2000,
<https://www.rfc-editor.org/rfc/rfc2782>.

[RFC2845] Vixie, P., Gudmundsson, O., Eastlake 3rd, D., and B.
Wellington, "Secret Key Transaction Authentication for DNS
(TSIG)", RFC 2845, DOI 10.17487/RFC2845, May 2000,
<https://www.rfc-editor.org/rfc/rfc2845>.

[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>.

[RFC4509] Hardaker, W., "Use of SHA-256 in DNSSEC Delegation Signer
(DS) Resource Records (RRs)", RFC 4509,
DOI 10.17487/RFC4509, May 2006,
<https://www.rfc-editor.org/rfc/rfc4509>.

[RFC5155] Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS
Security (DNSSEC) Hashed Authenticated Denial of
Existence", RFC 5155, DOI 10.17487/RFC5155, March 2008,
<https://www.rfc-editor.org/rfc/rfc5155>.

[RFC5936] Lewis, E. and A. Hoenes, Ed., "DNS Zone Transfer Protocol
(AXFR)", RFC 5936, DOI 10.17487/RFC5936, June 2010,
<https://www.rfc-editor.org/rfc/rfc5936>.

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[RFC6605] Hoffman, P. and W.C.A. Wijngaards, "Elliptic Curve Digital
Signature Algorithm (DSA) for DNSSEC", RFC 6605,
DOI 10.17487/RFC6605, April 2012,
<https://www.rfc-editor.org/rfc/rfc6605>.

[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
of Named Entities (DANE) Transport Layer Security (TLS)
Protocol: TLSA", RFC 6698, DOI 10.17487/RFC6698, August
2012, <https://www.rfc-editor.org/rfc/rfc6698>.

[RFC6763] Cheshire, S. and M. Krochmal, "DNS-Based Service
Discovery", RFC 6763, DOI 10.17487/RFC6763, February 2013,
<https://www.rfc-editor.org/rfc/rfc6763>.

[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>.

[RFC6891] Damas, J., Graff, M., and P. Vixie, "Extension Mechanisms
for DNS (EDNS(0))", STD 75, RFC 6891,
DOI 10.17487/RFC6891, April 2013,
<https://www.rfc-editor.org/rfc/rfc6891>.

[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>.

[RFC7553] Faltstrom, P. and O. Kolkman, "The Uniform Resource
Identifier (URI) DNS Resource Record", RFC 7553,
DOI 10.17487/RFC7553, June 2015,
<https://www.rfc-editor.org/rfc/rfc7553>.

[RFC7671] Dukhovni, V. and W. Hardaker, "The DNS-Based
Authentication of Named Entities (DANE) Protocol: Updates
and Operational Guidance", RFC 7671, DOI 10.17487/RFC7671,
October 2015, <https://www.rfc-editor.org/rfc/rfc7671>.

[RFC7766] Dickinson, J., Dickinson, S., Bellis, R., Mankin, A., and
D. Wessels, "DNS Transport over TCP - Implementation
Requirements", RFC 7766, DOI 10.17487/RFC7766, March 2016,
<https://www.rfc-editor.org/rfc/rfc7766>.

[RFC7873] Eastlake 3rd, D. and M. Andrews, "Domain Name System (DNS)
Cookies", RFC 7873, DOI 10.17487/RFC7873, May 2016,
<https://www.rfc-editor.org/rfc/rfc7873>.

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[RFC8078] Gudmundsson, O. and P. Wouters, "Managing DS Records from
the Parent via CDS/CDNSKEY", RFC 8078,
DOI 10.17487/RFC8078, March 2017,
<https://www.rfc-editor.org/rfc/rfc8078>.

[RFC8080] Sury, O. and R. Edmonds, "Edwards-Curve Digital Security
Algorithm (EdDSA) for DNSSEC", RFC 8080,
DOI 10.17487/RFC8080, February 2017,
<https://www.rfc-editor.org/rfc/rfc8080>.

[RFC8198] Fujiwara, K., Kato, A., and W. Kumari, "Aggressive Use of
DNSSEC-Validated Cache", RFC 8198, DOI 10.17487/RFC8198,
July 2017, <https://www.rfc-editor.org/rfc/rfc8198>.

[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/rfc/rfc8446>.

[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>.

[RFC8555] Barnes, R., Hoffman-Andrews, J., McCarney, D., and J.
Kasten, "Automatic Certificate Management Environment
(ACME)", RFC 8555, DOI 10.17487/RFC8555, March 2019,
<https://www.rfc-editor.org/rfc/rfc8555>.

[RFC8624] Wouters, P. and O. Sury, "Algorithm Implementation
Requirements and Usage Guidance for DNSSEC", RFC 8624,
DOI 10.17487/RFC8624, June 2019,
<https://www.rfc-editor.org/rfc/rfc8624>.

[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>.

[RFC8806] Kumari, W. and P. Hoffman, "Running a Root Server Local to
a Resolver", RFC 8806, DOI 10.17487/RFC8806, June 2020,
<https://www.rfc-editor.org/rfc/rfc8806>.

[RFC8976] Wessels, D., Barber, P., Weinberg, M., Kumari, W., and W.
Hardaker, "Message Digest for DNS Zones", RFC 8976,
DOI 10.17487/RFC8976, February 2021,
<https://www.rfc-editor.org/rfc/rfc8976>.

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[RFC9018] Sury, O., Toorop, W., Eastlake 3rd, D., and M. Andrews,
"Interoperable Domain Name System (DNS) Server Cookies",
RFC 9018, DOI 10.17487/RFC9018, April 2021,
<https://www.rfc-editor.org/rfc/rfc9018>.

[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>.

[RFC9462] Pauly, T., Kinnear, E., Wood, C. A., McManus, P., and T.
Jensen, "Discovery of Designated Resolvers", RFC 9462,
DOI 10.17487/RFC9462, November 2023,
<https://www.rfc-editor.org/rfc/rfc9462>.

[RFC9463] Boucadair, M., Ed., Reddy.K, T., Ed., Wing, D., Cook, N.,
and T. Jensen, "DHCP and Router Advertisement Options for
the Discovery of Network-designated Resolvers (DNR)",
RFC 9463, DOI 10.17487/RFC9463, November 2023,
<https://www.rfc-editor.org/rfc/rfc9463>.

Acknowledgments

The authors thank Ross Gibson for his contributions, questions and
comments.

Authors' Addresses

Jim Mozley
Infoblox, Inc.
Email: jmozley@infoblox.com

Nic Williams
Infoblox, Inc.
Email: nic@infoblox.com

Behcet Sarikaya
Unaffiliated
Email: sarikaya@ieee.org

Roland Schott
Deutsche Telecom
Email: roland.schott@telekom.de

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