Guidelines for Considering Operations and Management in IETF Specifications

Guidelines for Considering Operations and Management in IETF Specifications Everything OPS & Arrcus

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Operations and Management Operations and Management Area Working Group management operations operations and management ops considerations New Protocols and Protocol Extensions are best designed with due consideration of the functionality needed to operate and manage them. Retrofitting operations and management considerations is suboptimal. The purpose of this document is to provide guidance to authors and reviewers on what operational and management aspects should be addressed when writing documents in the IETF Stream that document a specification for New Protocols or Protocol Extensions or describe their use. This document obsoletes RFC 5706, replacing it completely and updating it with new operational and management techniques and mechanisms. It also updates RFC 2360 to obsolete mandatory MIB creation. Finally, it introduces a requirement to include an "Operational Considerations" section in new RFCs in the IETF Stream that define New Protocols or Protocol Extensions or describe their use (including relevant YANG Models), while providing an escape clause if no new considerations are identified.

Introduction Often, when New Protocols or Protocol Extensions are developed, not enough consideration is given to how they will be deployed, operated, and managed. Retrofitting operations and management mechanisms is often hard and architecturally unpleasant, and certain protocol design choices may make deployment, operations, and management particularly difficult or insecure. To ensure deployability, the operational environment and manageability must be considered during design. This document provides guidelines to help Protocol Designers and Working Groups (WGs) consider the operations and management functionality for their New Protocol or Protocol Extension at an early phase in the design process. This document obsoletes and updates its content with new operational and management considerations. It also introduces a requirement to include an "Operational Considerations" section in new RFCs in the IETF Stream that define New Protocols or Protocol Extensions or describe their use (including relevant YANG Data Models). This section must cover both operational and management considerations. Additionally, this document updates Section of RFC 2360 on "Guide for Internet Standards Writers" to obsolete references to mandatory MIBs and instead focus on documenting holistic manageability and operational considerations as described in . The update is provided in . Further, this document removes outdated references and aligns with current practices, protocols, and technologies used in operating and managing devices, networks, and services. Refer to for more details.

This Document This document provides a set of guidelines for considering operations and management in an IETF technical specification with an eye toward being flexible while also striving for interoperability. Entirely New Protocols may require significant consideration of expected operations and management, while Protocol Extensions to existing, widely deployed protocols may have established de facto operations and management practices that are already well understood. This document does not mandate a comprehensive inventory of all operational considerations. Instead, it guides authors to focus on key aspects that are essential for the technology's deployability, operation, and maintenance. Suitable operational and management approaches may vary for different areas, WGs, and protocols in the IETF. This document does not prescribe a fixed solution or format in dealing with operational and management aspects of IETF protocols. However, these aspects should be considered for any New Protocol or Protocol Extension. A WG may decide that its protocol does not need interoperable operational and management or a standardized Data Model, but this should be a deliberate and documented decision, not the result of omission. This document provides some guidelines for those considerations. This document recognizes a distinction between management and operational considerations, although the two are closely related. However, for New Protocols or Protocol Extensions only an "Operational Considerations" section is required. This section is intended to address both management and operational aspects. Operational considerations pertain to the deployment and functioning of protocols within a network, regardless of whether a management protocol is in active use. Management considerations focus on the use of management technologies, such as management protocols and the design of management Data Models. Both topics should be described within the "Operational Considerations" section. It is possible that the operational considerations will require significant amounts of text and need to be presented in a separate document. This saves the protocol specification from becoming overwhelmed or bloated. In this case the Operational Considerations section may contain just a short overview description of the material and a reference to other documents that contain the details, but those references must be normative.

Audience The guidelines are intended to be useful to authors writing protocol specifications. They outline what to consider for operations, management, and deployment, how to document those aspects, and how to present them in a consistent format. This document is intended to offer a flexible set of guiding principles applicable to various circumstances. It provides a framework for WGs to ensure that operational considerations are an integral part of the protocol design process, and its use should not be misinterpreted as imposing new hurdles on work in other areas. Protocol Designers should consider which operations and management needs are relevant to their protocol, document how those needs could be addressed, and suggest (preferably standard) management protocols and Data Models that could be used to address those needs. This is similar to a WG that considers which security threats are relevant to their protocol, documents (in the required Security Considerations section, per Guidelines for Writing RFC Text on Security Considerations ) how threats should be mitigated, and then suggests appropriate standard protocols that could mitigate the threats. It is not the intention that a protocol specification document should be held up waiting for operations and management solutions, or for supporting tooling, to be developed. This is particularly the case when a protocol extension is proposed, but the base protocol is missing operations or management solutions. However, it is the intent that new documents should clearly articulate the operations and management of that new work to fill any such gaps. Some operational and tooling guidance can only be determined through deployment experience. In such cases, authors should document what is reasonably foreseeable at design time. A core principle of this document is to encourage early-on discussions rather than mandating any specific solution. It does not impose a specific management or operational solution, imply that a formal Data Model is needed, or imply that using a specific management protocol is mandatory. Specifically, this document does not require developing solutions to accommodate identified operational considerations within the document that specifies a New Protocol or Protocol Extension itself. If Protocol Designers conclude that the technology can be managed solely by using Proprietary Interfaces or that it does not need any structured or standardized Data Model, this might be fine, but it is a decision that should be explicit in an operational considerations discussion -- that this is how the protocol will need to be operated and managed. Protocol Designers should avoid deferring operations and manageability to a later phase of the development of the specification. When a WG considers operations and management functionality for a protocol, the document should contain enough information for readers to understand how the protocol will be deployed, operated, and managed. The considerations do not need to be comprehensive and exhaustive; focus should be on key aspects. The WG should expect that considerations for operations and management may need to be updated in the future, after further operational experience has been gained. The Ops Directorate (OpsDir) can use this document to inform their reviews. A list of guidelines and a checklist of questions to consider, which a reviewer can use to evaluate whether the protocol and documentation address common operations and management needs, is provided in . Similarly, the Performance Metrics Directorate can use this document, together with the guidelines in , to inform reviews of the performance management aspects of a New Protocol or Protocol Extension. This document is also of interest to the broader community, who wants to understand, contribute to, and review Internet-Drafts, taking operational considerations into account.

Terminology This document does not describe interoperability requirements. As such, it does not use the capitalized keywords defined in . This section defines key terms used throughout the document to ensure clarity and consistency. Some terms are drawn from existing RFCs and IETF Internet-Drafts, while others are defined here for the purposes of this document. Where appropriate, references are provided for further reading or authoritative definitions.

Cause: See .
CLI: Command Line Interface. A human-oriented interface, typically a Proprietary Interface, to hardware or software devices (e.g., hosts, routers, or operating systems). The commands, their syntax, and the precise semantics of the parameters may vary considerably between different vendors, between products from the same vendor, and even between different versions or releases of a single product. No attempt at standardizing CLIs has been made by the IETF.
Data Model: A set of mechanisms for representing, organizing, storing, and handling data within a particular type of data store or repository. This usually comprises a collection of data structures such as lists, tables, relations, etc., a collection of operations that can be applied to the structures such as retrieval, update, summation, etc., and a collection of integrity rules that define the legal states (set of values) or changes of state (operations on values). A Data Model may be derived by mapping the contents of an Information Model or may be developed ab initio. Further discussion of Data Models can be found in , , and .
Fault: See .
Fault Management: The process of interpreting Fault notifications and other alerts and alarms, isolating Faults, correlating them, and deducing underlying Causes. See for more information.
Information Model: An abstraction and representation of the entities in a managed environment, their properties, attributes and operations, and the way that they relate to each other. The model is independent of any specific software usage, protocol, or platform . See Sections and for further discussion of Information Models.
Network Device: A device that implements one or more network protocols and participates in network operations. This term encompasses a broad range of implementations, including conventional network infrastructure equipment (e.g., routers and switches), end hosts, Internet of Things (IoT) devices, virtual network functions, and containerized workloads. In this document, the term is used generically to mean any managed entity implementing the protocol under consideration.
New Protocol and Protocol Extension: These terms are used in this document to identify entirely new protocols, new versions of existing protocols, and extensions to protocols. The application of New Protocols and Protocol Extensions to different scenarios, and their use in delivering services, procedures, mechanisms, or applications, falls within the scope of this definition.
OAM: Operations, Administration, and Maintenance is the term given to the combination of:
1. Operation activities that are undertaken to keep the network running as intended. They include monitoring of the network.
2. Administration activities that keep track of resources in the network and how they are used. They include the bookkeeping necessary to track networking resources.
3. Maintenance activities focused on facilitating repairs and upgrades. They also involve corrective and preventive measures to make the managed network run more effectively.
The broader concept of "operations and management" that is the subject of this document encompasses OAM, in addition to other management and provisioning tools and concepts. This is sometimes known as "OAM and Management" or "O&M" as explained in .
Operator: A person or organization responsible for deploying and managing systems, services, or networks that run or rely on a protocol implementation. This includes, but is not limited to, network operators, cloud service administrators, IoT device fleet managers, home network administrators, and DNS/NTP server administrators. The term "operator" is used throughout this document in this broad sense unless the context explicitly requires a narrower scope.
Performance Metrics: See .
Probable Root Cause: See .
Problem: See .
Proprietary Interface: An interface to manage a network element that is not standardized. As such, the user interface, syntax, and semantics typically vary significantly between implementations. Examples of proprietary interfaces include CLI, management web portal and Browser User Interface (BUI), Graphical User Interface (GUI), and vendor-specific application programming interface (API).
Protocol Designer: An individual, a group of people, or an IETF WG involved in the development and specification of New Protocols or Protocol Extensions.
Technical Document: This includes any document that describes the design, specification, implementation, or deployment of a new Protocol or Protocol Extensions.

Documentation Requirements for IETF Specifications

"Operational Considerations" Section All Internet-Drafts that document a technical specification for a New Protocol or Protocol Extension or describe their use are required to include an "Operational Considerations" section if it is the intention that they will be advanced for publication as IETF RFCs. Internet-Drafts that do not document technical specifications, such as process, policy, or administrative Internet-Drafts, are not required to include such a section. After evaluating the operational () and manageability () aspects of a New Protocol or Protocol Extension, the resulting practices and requirements should be documented in an "Operational Considerations" section within the specification. Since protocols are intended for operational deployment and management within real networks, it is expected that such considerations will be present. It is also recommended that operational and manageability considerations be addressed early in the protocol design process. Consequently, early revisions of Internet-Drafts are highly encouraged to include an "Operational Considerations" section. An "Operational Considerations" section should include a discussion of the management and operations topics raised in this document. When one or more of these topics is not relevant, it would be helpful to include a brief statement explaining why it is not relevant or applicable for the New Protocol or Protocol Extension. Of course, additional relevant operational and manageability topics should be included as well. A concise checklist of key questions is provided in . The section is always present. What it contains depends on the case:

Where the New Protocol or Protocol Extension raises operational and manageability considerations, the section discusses the relevant topics raised in this document.
Where one or more of those topics is not relevant, the section briefly explains why.
Where there are no new operations or manageability requirements at all, the section contains the statement in , followed by a brief rationale.
Where the considerations are already described in other parts of the same document, the section summarizes them and points to the relevant sections rather than repeating the material.
Where the considerations require significant text and are presented in a separate document, the section contains a short overview and a normative reference to that document, as described in .

For New Protocol or Protocol Extension specifications that contain Data Models (e.g., YANG) and other schema artifacts (JSON schema, YAML, CDDL, etc.), such artifacts may be consumed out of the RFCs that specify them. As such, it is recommended that operational aspects for a Data Model (and similar artifacts) are documented as part of the model itself. Such considerations should not be duplicated in the narrative part of a specification that includes such artifacts. For example:

Readers may refer to the following non-exhaustive list for examples of specifications, covering various areas, with adequate documentation of operational considerations, including manageability: , , , , , and . Given the various available transport alternatives, discusses co-existence with those and clarifies some key deployment aspects such as redirection, forwarding loop prevention, and error handling. Also, is an example of a document that follows the above guidance by documenting operational aspects as part of the YANG module itself.

For architecture documents, an "Operational Considerations" section is expected only where the architecture introduces new operational considerations with normative implications for downstream protocol designs. When included, it should focus on describing the intended deployment environment, assumptions about network operations, potential impacts on existing operational practices, and any high-level requirements that future protocol designs should address. It is not expected to detail specific configuration parameters or management interfaces unless they are integral to the architecture itself. If the architecture document does not introduce new operational considerations, the exemption statement in applies.

"Operational Considerations" Section Boilerplate When No New Considerations Exist After a Protocol Designer has considered the manageability requirements of a New Protocol or Protocol Extension, they may determine that no management functionality or operational best-practice clarifications are needed. It would be helpful to reviewers, those who may update or write extensions to the protocol in the future, and those deploying the protocol, to know the rationale for the decisions on the protocol's manageability at the time of its design. If there are no new manageability or deployment considerations, the "Operational Considerations" section must contain the following simple statement, followed by a brief explanation of why that is the case. The presence of such a section would indicate to the reader that due consideration has been given to manageability and operations. When the specification is a Protocol Extension, and the base protocol already addresses the relevant operational and manageability considerations, it is helpful to reference the considerations section of the base document.

Placement of the "Operational Considerations" Section It is recommended that the section be placed immediately before the Security Considerations section. Reviewers interested in this section will find it easily, and this placement could simplify the development of tools to detect its presence.

Changes Since RFC 5706 The following changes have been made to the guidelines published in :

Change intended status from Informational to Best Current Practice
Indicate that this document updates RFC 2360 and add the relevant updated text
Move the "Operational Considerations" checklist in to a Checklist maintained in GitHub
Add a concise "Operational Considerations Checklist" appendix () with key questions that should be addressed in protocol specifications
Add a requirement for an "Operational Considerations" section in all new RFCs that document a technical specification for a New Protocol or Protocol Extension or describe their use in the IETF Stream, along with specific guidance on its content.
Update the operational and manageability-related technologies to reflect over 15 years of advancements
- Provide focus and details on YANG-based standards, deprioritizing MIB Modules.
- Add a "YANG Data Model Considerations" section
- Update the "Available Management Technologies" landscape
Add an "Operational and Management Tooling Considerations" section

Update to RFC 2360 This document replaces this text from Section of RFC 2360 :

When relevant, each standard needs to discuss how to manage the protocol being specified. This management process should be compatible with the current IETF Standard management protocol. In addition, a MIB must be defined within the standard or in a companion document. The MIB must be compatible with current Structure of Management Information (SMI) and parseable using a tool such as SMICng. Where management or a MIB is not necessary this section of the standard should explain the reason it is not relevant to the protocol.

with the following:

When relevant, each standard needs to discuss how to manage the protocol being specified. Refer to RFC XXXX for holistic manageability and operational considerations.

Note to the RFC Editor: Please replace RFC XXXX with the RFC number to be assigned to this document.

How Will the New Protocol or Protocol Extension Fit into the Current Environment? Designers of a New Protocol or Protocol Extension should carefully consider the operational aspects of real-world deployments, which can directly impact its success. Such aspects include interactions with existing solutions, upgrade or deployment paths, the ability to debug problems, ease of configuration, and a state diagram that operations staff can understand. This exercise need not be reflected directly in their document, but could help visualize how to apply the protocol in the environments where it will be deployed. provides a more detailed discussion on what makes for a successful protocol. Not every operational consideration can be foreseen at design time. Some considerations reside in how a specification is applied and deployed rather than in the specification itself, and may only become apparent once operational experience has been gained. In some cases, the relevant questions are not even known in advance. Authors should document what is reasonably foreseeable without speculating, and should expect that operational considerations may need to be revisited as deployment experience accumulates. For example:

BGP flap damping was designed to block high-frequency route flaps. Some BGP implementations were memory-constrained and elected not to support this function. Others found a conflict where path exploration caused false flap damping resulting in loss of reachability. As a result, flap damping was often not enabled network-wide, contrary to the intentions of the original designers. This behavior emerged only from operational experience at scale, and little text written at design time would have changed the outcome.

Installation and Initial Setup Anything that can be configured can be misconfigured. ("Architectural Principles of the Internet") states:

Avoid options and parameters whenever possible. Any options and parameters should be configured or negotiated dynamically rather than manually.

The New Protocol or Protocol Extension should be able to operate "out of the box". To simplify configuration, Protocol Designers should specify reasonable defaults, including default modes and parameters. For example, define default values for modes, timers, default state of logical control variables, default transports, and so on. Protocol Designers should explain the background of the chosen default values and provide the rationale. In many cases, as technology changes, the documented values might make less and less sense. It is helpful to understand whether defaults are based on best current practice and are expected to change as technologies advance, or whether they have a more universal value that should not be changed lightly. For example, the default interface speed might change over time as network speeds increase, and cryptographic algorithms might be expected to change over time as older algorithms are "broken". Default values should generally favor the conservative side over the "optimizing performance" side (e.g., the initial Round-Trip Time (RTT) and Round-Trip Time Variance (RTTVAR) values of a TCP connection ). For parameters that can vary (e.g., speed-dependent), instead of using a constant, set the default value as a function of the variable to reduce the risk of problems caused by technology advancement. It must always be possible for an operator to retrieve the actual value in use, to determine that the element is running at a known default. This is important for troubleshooting, auditing, and ensuring consistent behavior across implementations. For example:

Where protocols involve cryptographic keys, Protocol Designers should consider not only key generation and validation mechanisms but also the format in which private keys are stored, transmitted, and restored. Designers should specify any expected consistency checks (e.g., recomputing an expanded key from the seed) that help verify correctness and integrity. Additionally, guidance should be given on data retention, restoration limits, and cryptographic module interoperability when importing/exporting private key material. Refer to for an example of how such considerations are incorporated.

Migration Path If the New Protocol or Protocol Extension is a new version of an existing one, or if it is replacing another technology, the Protocol Designer should consider how deployments should transition to the New Protocol or Protocol Extension. This should include coexistence with previously deployed protocols and/or previous versions of the same protocol, management of incompatibilities between versions, translation between versions, and consideration of potential side effects. A key question is: Are older protocols or versions disabled, or do they coexist with the New Protocol or Protocol Extension in the network? Many protocols benefit from being incrementally deployable -- operators may deploy some aspects of a protocol before deploying it fully, or may deploy to only some nodes in a network before applying to all nodes in the network. In those cases, the operational considerations should also specify whether the New Protocol or Protocol Extension requires any changes to the existing infrastructure, particularly the network. If so, the protocol specification should describe the nature of those changes, where they are required, and how they can be introduced in a manner that facilitates deployment. Where possible, backward-compatible approaches should be preferred over non-backward-compatible ones, since they typically provide a smoother migration path with lower cost and impact on existing deployments. Security operations () are important to ensure the stability and security of networks. Good security operation practices should be encouraged when migrating to a New Protocol or Protocol Extension. For example, patching (i.e., installing new versions that have fixes for security vulnerabilities) is fundamental for security operations, and can be made much easier if Protocol Designers consider supporting cheap and fast connection hand-offs and reconnections. When Protocol Designers are considering how deployments should transition to the New Protocol or Protocol Extension, impacts to current techniques employed by operators should be documented and mitigations included, where possible, so that consistent security operations and management can be achieved. Note that transitioning between security mechanisms can be challenging, but it is not desirable to take an easier approach if that leaves data in an open or less-protected state during the transition. Refer to for a detailed discussion on transition versus coexistence.

Requirements on Other Protocols and Functional Components Protocol Designers should consider the requirements that the New Protocol might put on other protocols and functional components and should also document the requirements from other protocols and functional components that have been considered in designing the New Protocol. These considerations should generally remain illustrative to avoid creating restrictions or dependencies, or potentially impacting the behavior of existing protocols, or restricting the extensibility of other protocols, or assuming other protocols will not be extended in certain ways. If restrictions or dependencies exist, they should be stated. Where a New Protocol or Protocol Extension depends on another protocol or component to function correctly, that dependency is a normative property of the specification and belongs in its main body rather than only in the "Operational Considerations" section, so that implementers and operators can identify it easily. For example, if correct operation relies on an accurate time source (such as NTP ), the specification should state that requirement, and the acceptable means of satisfying it, explicitly. Another example:

The design of the Resource ReSerVation Protocol (RSVP) required each router to look at the RSVP PATH message and, if the router understood RSVP, add its own address to the message to enable automatic tunneling through non-RSVP routers. But in reality, routers cannot look at an otherwise normal IP packet and potentially take it off the fast path! The initial designers overlooked that a new "deep-packet inspection" requirement was being put on the functional components of a router. The "router alert" option (, ) was finally developed to solve this problem, for RSVP and other protocols that require the router to take some packets off the fast-forwarding path. Yet, Router Alert has its own problems in impacting router performance and security. Refer to for deprecation of the IPv6 Router Alert Option for New Protocols and Section of RFC 7126 for threats and advice related to IPv4 Router Alert.

Impact on Network Operation The introduction of a New Protocol or Protocol Extension may have an impact on the operation of existing networks, as well as on the hosts, devices, and systems that implement or depend on the protocol. As discussed in major extensions may have characteristics leading to a risk of operational problems. Protocol Designers should outline such operational impacts (which may be positive), including scaling benefits or concerns, and interactions with other protocols. Protocol Designers should describe the scenarios in which the New Protocol or its extensions are expected to be applicable or beneficial. This includes any relevant deployment environments, network topologies, usage constraints such as limited domains , or use cases that justify or constrain adoption. For example, a New Protocol or Protocol Extension that doubles the number of active, reachable addresses in a network might have implications for the scalability of interior gateway protocols, and such impacts should be evaluated accordingly. Per Section of RFC 2360 , New Protocol or Protocol Extension specifications should establish the limitations on the scale of use and limits on the resources used. If the protocol specification requires changes to end hosts or network infrastructure, it should indicate whether safeguards exist to protect both end hosts and devices and the broader network from potential overload. Moreover, per Section of RFC 2360 , New Protocol or Protocol Extension specifications should address any possible destabilizing events, and means by which the protocol resists or recovers from them. For instance, a congestion control algorithm must comply with to prevent congestion collapse and ensure network stability. A protocol could send active monitoring packets on the wire. Without careful consideration, active monitoring might achieve high accuracy at the cost of generating an excessive number of monitoring packets. Protocol Designers should consider the potential impact on the behavior of other protocols in the network and on the traffic levels and traffic patterns that might change, including specific types of traffic, such as multicast. Also, consider the need to install new components that are added to the network as a result of changes in the configuration, such as servers performing auto-configuration operations. Protocol Designers should also consider the impact on infrastructure applications such as the DNS , the registries, or the size of routing tables. For example:

SMTP servers use a reverse DNS lookup to filter out incoming connection requests: when Berkeley installed a new spam filter that used reverse DNS lookup, their mail server stopped functioning because of overload of the DNS cache resolver.

The impact of New Protocols or Protocol Extensions, and the results of new OAM tools developed for them, must be considered with respect to traffic delivery performance and ongoing manageability. For example, it must be noted whether the New Protocol, Protocol Extension, or OAM tools cause increased delay or jitter in real-time traffic applications, or increased response time in client-server applications. Further, if the additional traffic caused by OAM tools and data collection could result in the management plane becoming overwhelmed, then this must be called out, and suitable mechanisms to rate limit the OAM traffic must be considered. Potential options include: document the limitations, propose solution track(s), include an optional rate limiting feature in the specifications, or impose a rate limiting feature in the specifications. For example:

(1) In Bidirectional Forwarding Detection (BFD) for MPLS it is possible to configure very rapid BFD transmissions (of the order of 3ms) on a very large number of parallel Label Switched Paths (LSPs) with the result that the management systems and end nodes may become overwhelmed -- this can be protected by applying limits to the number of LSPs that may be tested at once. (2) Notifications or logs from systems (through YANG or other means) should be rate-limited so that they do not flood the receiving management station. (3) The application of sophisticated encryption or filtering rules needs to be considered in the light of the additional processing they may impose on the hardware forwarding path for traffic.

New metrics may be required to assess traffic performance. Protocol Designers may refer to for guidelines for considering new performance metrics. Protocol Designers should account for MTU constraints when designing protocols that carry management traffic or measurement data, including any reduction in effective payload size introduced by tunnel or encapsulation overhead. specifies path MTU discovery for datagram transports, and gives recommendations for protocol developers on avoiding reliance on IP fragmentation.

Impact on Security Operations Security Operations (SecOps) is a collaborative approach that combines security and operational teams to improve the ability of operators to protect and manage the network effectively and efficiently . Security operators detect malicious activity and respond to threats and are a crucial part of defending against attacks alongside the management and operation of the network. Protocol Designers should consider the impacts of a New Protocol or Protocol Extension on Security Operations in networks that the protocol will be deployed in. Security operators extensively rely upon Indicators of Compromise (IoCs) . The deployment of a New Protocol or Protocol Extension may change the type, locations, or availability of IoCs. Protocol Designers should outline such changes to ensure operators can manage and defend their networks, systems, and devices consistently. Consider the operators' requirement for digital forensics from the network or endpoints with critical information found in logs. Logging events schema and guidance for operators should be considered when designing a New Protocol or Protocol Extension to ensure operators have the information they need. is an example of extensible structured logging. An increasing number of New Protocols and Protocol Extensions encrypt metadata that was previously available to passive inspection, such as QUIC , TLS 1.3 , Encrypted Client Hello , and DNS over HTTPS (DoH) . This creates a tension between the privacy goals of such protocols and the visibility that security operators have historically relied upon. Protocol Designers should acknowledge this tension and, where passive visibility is reduced, consider alternative diagnostic mechanisms, such as endpoint-based telemetry or logging, that preserve operators' ability to detect and respond to threats without undermining the protocol's privacy objectives. Tooling needed by security operators should be considered when designing and deploying a New Protocol or Protocol Extension. Operators may require new tooling or methods for managing network traffic in response to protocol changes to ensure consistent availability and performance of networks. Similarly, updating and augmenting existing forensic tools such as protocol dissectors is expected when a New Protocol is deployed, but having to completely rebuild such tooling would greatly reduce the effectiveness of security operators, so protocol extensibility should be considered. The absence of such tooling is not, by itself, a reason to delay publication of the specification. Indicators of compromise, and the means to detect exploitation, tend to evolve only as operational experience accumulates and as attacks emerge. Detailed forensic and tooling guidance may therefore be developed after the protocol is specified and is expected to be refined over time (see also ). For further information on the security operations considerations discussed in this section, refer to .

Verifying Correct Operation An important function that should be provided is guidance on how to verify the correct operation of a protocol. A Protocol Designer may suggest testing techniques for qualifying and quantifying the impact of the protocol on the network before it is partially or fully deployed, as well as testing techniques for identifying the effects that the protocol might have on the network after being deployed. Protocol Designers should consider techniques for testing the effect the protocol has had on the infrastructure by sending data through it and observing its behavior (also known as active monitoring). Protocol Designers should consider how the correct end-to-end operation of the New Protocol or Protocol Extension can be tested actively and passively, and how the correct data- or forwarding-plane function of each involved element can be verified to be working correctly with the New Protocol or Protocol Extension. Protocol Designers should consider how to test the correct end-to-end operation of the service or network, how to verify correct protocol behavior, and whether such verification is achieved by testing the service function and/or the forwarding function of each network element. This may be accomplished through the collection of status and statistical information gathered from devices. Having simple protocol status and health indicators on involved devices is a recommended means to check correct operation.

Message Formats Where protocol specifications result in messages (such as errors or warnings) being carried as text strings or output for consumption by human operators, consideration should be given to making it possible for implementations to be configured so that the messages can be viewed in the local language. In such cases, it is helpful to transmit a specific message code (i.e., a number) along with the message text, and to include a language tag (as described in ) to enable correct identification and rendering in the appropriate language. Protocol specifications should not assume English as the default language. Further discussion of Internationalization issues may be found in .

How Will the Protocol Be Managed? The considerations of manageability should start from identifying the entities to be managed, as well as how the managed protocol is supposed to be installed, configured, and monitored. Considerations for management should describe what aspects of the system require management and the management functions that need to be supported. This includes identifying any assumptions or constraints relevant to management interactions, such as the types of interfaces or protocols required. These considerations should avoid dependence on a specific management deployment model and should remain applicable regardless of where management systems are located or how they are accessed. The management model should take into account factors such as:

What type of management entities will be involved (agents, network management systems)?
What is the possible architecture (client-server, manager-agent, poll-driven or event-driven, auto-configuration, two-levels or hierarchical)?
What are the management operations (initial configuration, dynamic configuration, alarm and exception reporting, logging, performance monitoring, performance reporting, debugging)?
How are these operations performed (locally, remotely, atomic operation, scripts)? Are they performed immediately or are they time scheduled, or event triggered?

Protocol Designers should consider how the New Protocol or Protocol Extension will be managed in different deployment scales. It might be sensible to use a local management interface to manage the New Protocol or Protocol Extension on a single device, but in a large network, remote management using a centralized server and/or using distributed management functionality might make more sense. Auto-configuration and default parameters might be possible for some New Protocols or Protocol Extensions. Management needs to be considered not only from the perspective of a device, but also from the perspective of network and service management. A service might be network and operational functionality derived from the implementation and deployment of a New Protocol or Protocol Extension. Often, an individual network element is unaware of the service being delivered. WGs should consider how to configure multiple related/co-operating devices and how to back off if one of those configurations fails or causes trouble. Network Configuration Protocol (NETCONF) addresses this in a generic manner by allowing an operator to lock the configuration on multiple devices, perform the configuration settings/changes, check that they are OK (undo if not), and then unlock the devices. Techniques for debugging protocol interactions in a network must be part of the network management discussion. Implementation source code should be debugged before ever being added to a network, so asserts and memory dumps do not normally belong in management data models. However, debugging on-the-wire interactions is a protocol issue: while the messages can be seen by sniffing, it is enormously helpful if a protocol specification supports features that make debugging of network interactions and behaviors easier. There could be alerts issued when messages are received or when there are state transitions in the protocol state machine. However, the state machine is often not part of the on-the-wire protocol; the state machine explains how the protocol works so that an implementer can decide, in an implementation-specific manner, how to react to a received event. In a client/server protocol, it may be more important to instrument the server end of a protocol than the client end, since the performance of the server might impact more nodes than the performance of a specific client. The subsections from through are organized following the Fault, Configuration, Accounting, Performance, and Security (FCAPS) network management framework.

Available Management Technologies The IETF provides several standardized management protocols suitable for various operational purposes, for example as outlined in . Note that SNMP is no longer recommended for configuration (read-write) operations. Better programmatic alternatives are discussed further in Section . This document formally deprecates the following recommendation from :

a MIB must be defined within the standard or in a companion document.

Data collection practice has evolved substantially since was published. Designers should also consider mechanisms developed since, including the BGP Monitoring Protocol (BMP) , subscription to YANG notifications , and the alarm management model ; provides a framework relating these to one another. Readers seeking more in-depth definitions or explanations should consult the referenced materials.

Interoperability Management interoperability is critical for enabling information exchange and operations across diverse network devices and management applications, regardless of vendor, model, or software release. It facilitates the use of third-party applications and outsourced management services. While individual device management via Proprietary Interfaces may suffice for small deployments, large-scale networks comprising equipment from multiple vendors necessitate consistent, automated management. Relying on vendor- and model-specific interfaces for extensive deployments, such as hundreds of branch offices, severely impedes scalability and automation of operational processes. The primary goal of management interoperability is to enable the scalable deployment and lifecycle management of new network functions and services, while ensuring a clear understanding of their operational impact and total cost of ownership. Achieving universal agreement on a single management syntax and protocol is challenging. However, the IETF has significantly evolved its approach to network management, moving beyond Structure of Management Information version 2 (SMIv2) and SNMP. Modern IETF management solutions primarily leverage YANG for Data Modeling and NETCONF or RESTful Configuration Protocol (RESTCONF) for protocol interactions. This shift, as further elaborated in , emphasizes structured Data Models and programmatic interfaces to enhance automation and interoperability. Other protocols, such as IP Flow Information Export (IPFIX) for flow accounting and syslog (System Logging Protocol) for logging, continue to play specific roles in comprehensive network management. Interoperability must address both syntactic and semantic aspects. While syntactic variations across implementations can often be handled through adaptive processing, semantic differences pose a greater challenge, as the meaning of data is intrinsically tied to the managed entity. Information Models (IMs) enable and provide the foundation for semantic interoperability. An IM defines the conceptual understanding of managed information, independent of specific protocols or vendor implementations. This allows for consistent interpretation and correlation of data across different Data Models (and hence management protocols), such as a YANG Data Model and IPFIX Information Elements concerning the same event. For instance, an IM can standardize how error conditions are counted, ensuring that a counter has the same meaning whether collected via NETCONF or exported via IPFIX. Protocol Designers should consider developing an IM, when multiple Data Model (DM) representations (e.g., YANG and/or IPFIX) are required, to ensure lossless semantic mapping. IMs are also beneficial for complex or numerous DMs. As illustrated in , an IM serves as a conceptual blueprint for designers and operators, from which concrete DMs are derived for implementers. provides further guidance on distinguishing IMs from DMs.

Information Models (IMs) and Data Models (DMs) conceptual/abstract model | for designers & operators +----------+---------+ | | | DM DM DM --> concrete/detailed model for implementers ]]> Protocol Designers must identify the essential operational, configuration, state, and statistical information required for effective monitoring, control, and troubleshooting of New Protocols or Protocol Extensions. This includes defining relevant parameters, performance metrics, error indicators, and contextual data crucial for diagnostics and lifecycle management. To ensure interoperability, management protocol and Data Model standards should incorporate clear compliance clauses, specifying the expected level of support.

Management Information Languages used to describe an Information Model can influence the nature of the model. Using a particular data modeling language, such as YANG, influences the model to use certain types of structures, for example, hierarchical trees, groupings, and reusable types. YANG, as described in and , provides advantages for expressing network information, including clear separation of configuration data and operational state, support for constraints and dependencies, and extensibility for evolving requirements. Its ability to represent relationships and dependencies in a structured and modular way makes it an effective choice for defining management information models. While an Information Model is typically described in English text (or sometimes the Unified Modeling Language (UML)) to define the conceptual management requirements, authors may choose to express it using YANG Data Structure Extensions as described in . Using YANG for the Information Model can make it easier to link abstract concepts to concrete data types in the corresponding Data Model, helping maintain consistency between high-level design and practical deployment. A management Information Model should include a discussion of what is manageable, which aspects of the protocol need to be configured, what types of operations are allowed, what protocol-specific events might occur, which events can be counted, and for which events an operator should be notified. There may be a need to support both CLI (e.g., for troubleshooting) and a programmatic interface (e.g., for automated monitoring and Cause analysis). The APIs and CLI should expose consistent information so that an operator receives the same view of the protocol state regardless of which interface is used. Counter definitions, in particular, should be unambiguous and consistently defined across both types of interface. When defining management information, it is important to categorize data into configuration, operational state, and statistics. Conflating these distinct types into a single element makes it difficult for operators to distinguish between administratively set values and the dynamic state of the protocol. The model should be structured to allow these categories to be handled independently. What is typically difficult to work through are relationships between abstract objects. Ideally, an Information Model would describe the relationships between the objects and concepts in the information model. Is there always just one instance of this object or can there be multiple instances? Does this object relate to exactly one other object, or may it relate to multiple? When is it possible to change a relationship? Do objects (such as instances in lists) share fate? For example, if an instance in list A must exist before a related instance in list B can be created, what happens to the instance in list B if the related instance in list A is deleted? Does the existence of relationships between objects have an impact on fate sharing? YANG's relationships and constraints can help express and enforce these relationships.

Information Model Design This document recommends keeping the Information Model as simple as possible by applying the following criteria:

Start with a small set of essential objects and make additions only as further objects are needed, with the objective of keeping the absolute number of objects as small as possible while still delivering the required function. Essential objects are those needed to answer the diagnostic, configuration, and operational questions the protocol is expected to support; objects that are technically accessible but do not serve these functions should be excluded. There should be no duplication between objects, and where one piece of information can be derived from other pieces of information, it should not itself be represented as an object.
Verify that each object serves a distinct management purpose and cannot be derived from other objects already in the model. Objects that are redundant or that conflate multiple concerns should be split or eliminated.
Consider evidence of current use of the managed protocol, and the perceived utility of objects added to the Information Model.
Exclude objects that can be derived from others in this or other Information Models.
Avoid heavy instrumentation of performance-critical code paths or state that is expensive to query or compute. A guideline is to limit instrumentation to one counter per significant processing stage or operational boundary per layer.
When expressing an Information Model using YANG Data Structure Extensions (thereby keeping it abstract and implementation-agnostic per ), ensure that the Information Model remains simple, modular, and clear by following the authoring guidelines in .
When illustrating the abstract Information Model, use YANG Tree Diagrams to provide a simple, standardized, and implementation-neutral model structure.

YANG Data Model Considerations When considering YANG Data Models for a new specification, there are multiple types of Data Models that may be applicable. The hierarchy and relationship between these types is described in . A new specification may require or benefit from one or more of these YANG Data Model types.

Device Models - Also called Network Element Models, represent the configuration, operational state, and notifications of individual devices. These models are designed to distinguish between these types of data and support querying and updating device-specific parameters. Consideration should be given to how device-level models might fit with broader network and service Data Models.
Network Models - Also called Network Service Models, define abstractions for managing the behavior and relationships of multiple devices and device subsystems within a network. As described in , these models are used to manage network-wide services. These abstractions are useful to network operators and applications that interface with network controllers. Examples of network models include the L3VPN Network Model (L3NM) and the L2VPN Network Model (L2VPN) .
Service Models - Also called Customer Service Models, defined in , are designed to abstract the customer interface into a service. They consider customer-centric parameters such as Service Level Agreement (SLA) and high-level policy (e.g., network intent). Given that different operators and different customers may have widely-varying business processes, these models should focus on common aspects of a service with strong multi-party consensus. Examples of service models include the L3VPN Service Model (L3SM) and the L2VPN Service Model (L2SM) .

A common challenge in YANG Data Model development lies in defining the relationships between abstract service or network constructs and the underlying device models. Therefore, when designing Network and Service YANG modules, consider how the status and relationships of abstract or distributed constructs can be reflected based on parameters available in the network. The status of a service may depend on the operational state of multiple network elements to which the service is attached. In such cases, the YANG Data Model (and its accompanying documentation) should clearly describe how service-level status is derived from underlying network-level abstractions and device-level information. Similarly, it is beneficial to define events (and relevant triggered notifications) at the device, network, and service levels that indicate changes in an underlying state, enabling reliable detection and correlation of service-affecting conditions across these levels. Including such mechanisms improves the robustness of integrations and helps ensure consistent behavior across implementations. For example:

A device YANG module may define a notification indicating that a hardware component, such as a line card, has failed. An implementation (e.g., a network controller that is aware of device inventory) can correlate such a device-level notification with the interfaces hosted on the affected line card and their subsequent down status to determine that a link supporting the network is no longer operational, and expose a corresponding network-level notification using a Network Model such as L3NM . Likewise, an implementation managing the service layer can correlate that network-level notification with the affected service and use a Service Model such as L3SM to report a service-degraded event to the customer, without requiring the service-facing model to expose device-level detail.

Specific guidelines to consider when authoring any type of YANG modules are described in .

Fault Management Protocol Designers should identify and document essential Faults, health indicators, alarms, and events that must be propagated to management applications or exposed through a Data Model. It is also recommended to describe how the Protocol Extension will affect the existing alarms and notification structure of the base Protocol, and to outline the potential impact of misconfigurations of the Protocol Extensions. Protocol Designers should consider how Fault information will be propagated. Will it be done using asynchronous notifications or polling of health indicators? If notifications are used to alert operators to certain conditions, then Protocol Designers should discuss mechanisms to throttle notifications to prevent congestion and duplications of event notifications. Will there be a hierarchy of Faults, and will the Fault reporting be done by each Fault in the hierarchy, or will only the lowest Fault be reported and the higher levels be suppressed? Should there be aggregated status indicators based on concatenation of propagated Faults from a given domain or device? The alarm management model already addresses many of these questions, including alarm identification, severity, root cause and impacted resource, and shelving for suppression; it also distinguishes alarm state from the notifications that report it. Protocol Designers should consider reusing it rather than defining new notification structures. Notifications (e.g., SNMP traps and informs, syslog, or protocol-specific mechanisms) can alert an operator when an aspect of the New Protocol or Protocol Extension fails or encounters an error or failure condition. Should the event reporting provide guaranteed accurate delivery of the event information within a given (high) margin of confidence? Can the latest events in the box be polled?

Liveness Detection and Monitoring Protocol Designers should build in basic testing features (e.g., ICMP echo, UDP or TCP echo services, and null Remote Procedure Calls (RPCs)) that can be used to test for liveness, with the option to enable or disable them. Mechanisms for monitoring the liveness of the protocol and for detecting Faults in protocol connectivity are usually built into protocols. In some cases, mechanisms already exist within other protocols responsible for maintaining lower-layer connectivity (e.g., ICMP echo), but often new procedures are required to detect failures and to report rapidly, allowing remedial action to be taken. These liveness monitoring mechanisms do not typically require additional management capabilities. However, when a system detects a Fault, there is often a requirement to coordinate recovery action through management applications or at least to record the fact in an event log.

Fault Determination It can be helpful to describe how Faults can be pinpointed using management information. For example, counters might record instances of error conditions. Some Faults might be able to be pinpointed by comparing the outputs of one device and the inputs of another device, looking for anomalies. Protocol Designers should consider what counters should count. If a single counter provided by vendor A counts three types of error conditions, while the corresponding counter provided by vendor B counts seven types of error conditions, these counters cannot be compared effectively -- they are not interoperable counters. How do you distinguish between faulty messages and good messages? Would some threshold-based mechanisms be usable to help determine error conditions? Are notifications for all events needed, or are there some "standard" notifications that could be used? Or can relevant counters be polled as needed? For example:

Remote Monitoring (RMON) events/alarms provide a threshold-based mechanism.

Probable Root Cause Analysis Probable Root Cause analysis is about working out where the foundational Fault or Problem might be. Since one Fault may give rise to another Fault or Problem, a Probable Root Cause is commonly meant to describe the original, source event or combination of circumstances that is the foundation of all related Faults. For example:

If end-to-end data delivery is failing (e.g., reported by a notification), Probable Root Cause analysis can help find the failed link or node, or mis-configuration, within the end-to-end path.

Fault Isolation It might be useful to isolate or quarantine Faults. Protocol Designers should consider Fault isolation mechanisms appropriate to the deployment environment. At the network level, this might involve configuring next-hop devices to drop faulty messages to prevent them from propagating through the network, such as isolating a device that emits malformed messages that are necessary to coordinate connections properly. At the host level, isolation mechanisms may include process quarantine, container or virtual machine isolation, or disabling a misbehaving protocol implementation without disrupting other services on the same device. The range of appropriate isolation mechanisms will depend on where the protocol is deployed and the nature of the Fault.

Configuration Management Configuration management applies to a broad range of deployment environments, including conventional network devices, IoT device fleets, containerized workloads, cloud-hosted services, and home network equipment. While many examples in this section are drawn from network device management, the principles apply equally to any environment where the protocol is deployed. Protocol Designers should consider how configuration is managed in the environments relevant to their protocol, acknowledging centralized configuration management approaches (e.g., intent-based or model-driven systems) beyond conventional per-device management. A Protocol Designer should document the basic configuration parameters that need to be instrumented for a New Protocol or Protocol Extension, as well as default values and modes of operation. What information should be maintained across reboots of the device, or restarts of the management system? "Requirements for Configuration Management of IP-based Networks" discusses requirements for configuration management, including discussion of different levels of management, high-level policies, network-wide configuration data, and device-local configuration. Network configuration extends beyond simple multi-device push or pull operations. It also involves ensuring that the configurations being pushed are semantically compatible across devices and that the resulting behavior of all involved devices corresponds to the intended behavior. Is the attachment between them configured compatibly on both ends? Is the IS-IS metric the same? Answering those questions for a network with one thousand devices is not that easy. Several efforts have existed in the IETF to develop policy-based configuration management. "Terminology for Policy-Based Management" was written to standardize the terminology across these efforts. Implementations should not arbitrarily modify configuration data. If a Protocol Designer defines mechanisms for configuration, it would be preferable to standardize the order of elements for consistency of configuration and of reporting across vendors and across releases from vendors. Network-wide configurations may be stored in central databases and transformed into readable formats that can be pushed to devices, either by generating sequences of CLI commands or complete textual configuration files that are pushed to devices. There is no common database schema for network configuration, although the models used by various operators are probably very similar. It is operationally beneficial to extract, document, and standardize the common parts of these network-wide configuration database schemas. A Protocol Designer should consider how to standardize the common parts of configuring the New Protocol, while recognizing that vendors may also have proprietary aspects of their configurations. It is important to enable operators to concentrate on the configuration of the network or service as a whole, rather than individual devices. Support for configuration transactions across several devices could significantly simplify network configuration management. The ability to distribute configurations to multiple devices, or to modify candidate configurations on multiple devices, and then activate them in a near-simultaneous manner might help. Protocol Designers can consider how it would make sense for their protocol to be configured across multiple devices. Configuration templates might also be helpful. Consensus of the 2002 IAB Network Management Workshop was that textual configuration files should be able to contain international characters. For human-readable strings carried in protocols, provides guidance on the use of UTF-8 with NFC normalization for consistent encoding of Unicode text; protocol elements that are not intended for human consumption may remain in ASCII. Requirements for the encoding of device-local configuration files are generally outside the scope of IETF standardization and should be handled appropriately for the deployment environment. A mechanism to dump-and-restore configurations is a primitive operation needed by operators. Standards for pulling and pushing configurations from/to devices are highly beneficial. Given configuration A and configuration B, it should be possible to generate the operations necessary to get from A to B with minimal state changes and effects on network and systems. It is important to minimize the impact caused by configuration changes. A Protocol Designer should consider the configurable items that exist for the control of function via the protocol elements described in the protocol specification. For example, sometimes the protocol requires that timers can be configured by the operator to ensure specific policy-based behavior by the implementation. These timers should have default values suggested in the protocol specification and may not need to be otherwise configurable.

Accounting Management A Protocol Designer should consider whether it would be appropriate to collect usage information related to this protocol and, if so, what usage information would be appropriate to collect. "Introduction to Accounting Management" discusses a number of factors relevant to monitoring usage of protocols for purposes of capacity and trend analysis, cost allocation, auditing, and billing. The document also discusses how some existing protocols can be used for these purposes. These factors should be considered when designing a protocol whose usage might need to be monitored or when recommending a protocol to do usage accounting.

Performance Management From a manageability point of view, it is important to determine how well a network deploying the protocol or technology defined in the document is doing. In order to do this, the network operators need to consider information that would be useful to determine the performance characteristics of a deployed system using the target protocol. The IETF, via the Benchmarking Methodology WG (BMWG), has defined recommendations for the measurement of the performance characteristics of various internetworking technologies in a laboratory environment, including the systems or services that are built from these technologies, building on the foundational methodology in . Each benchmarking recommendation describes the class of equipment, system, or service being addressed; discusses the performance characteristics that are pertinent to that class; clearly identifies a set of metrics that aid in the description of those characteristics; specifies the methodologies required to collect said metrics; and lastly, presents the requirements for the common, unambiguous reporting of benchmarking results. Performance metrics may be useful in multiple environments and for different protocols. The IETF, via the IP Performance Measurement (IPPM) WG, has developed a set of standard metrics, building on the framework defined in , that can be applied to the quality, performance, and reliability of Internet data delivery services. These metrics are designed such that they can be performed by network operators, end users, or independent testing groups. The existing metrics might be applicable to the new protocol. Search for "metric" in the RFC search tool. In some cases, new metrics need to be defined. It would be useful if the protocol documentation identified the need for such new metrics. For performance management, it is often more important to report the time spent in a state rather than just the current state. Snapshots alone are typically of less value. classifies measurement methods as active, passive, or hybrid. This classification is relevant to the protocol, device, network, and service monitoring approaches discussed in , , , and . There are several parts of performance management to consider: protocol monitoring, device monitoring (the impact of new functionality/service activation on the device), network monitoring, and service monitoring (the impact of service activation on the network). Hence, if the implementation of the New Protocol or Protocol Extension has any significant hardware/software performance implications (e.g., increased CPU utilization, memory consumption, or forwarding performance degradation), the Protocol Designers should clearly describe these impacts in the specification, along with any conditions under which they may occur and possible mitigation strategies.

Monitoring the Protocol Certain properties of protocols are useful to monitor. The number of protocol packets received, the number of packets sent, and the number of packets dropped are usually very helpful to operators. Packet drops should be reflected in counter variable(s) somewhere that can be inspected -- both from the security point of view and from the troubleshooting point of view. Counter definitions should be unambiguous about what is included in the count and what is not included in the count. Consider the expected behaviors for counters -- what is a reasonable maximum value for expected usage? Should they stop counting at the maximum value and retain it, or should they rollover? Guidance should explain how rollovers are detected, including multiple occurrences. Consider whether multiple management applications will share a counter; if so, then no one management application should be allowed to reset the value to zero since this will impact other applications. Could events, such as hot-swapping a blade in a chassis, cause discontinuities in counter? Does this make any difference in evaluating the performance of a protocol? The protocol specification should clearly define any inherent limitations and describe expected behavior when those limits are exceeded. These considerations should be made independently of any specific management protocol or data modeling language. In other words, focus on what makes sense for the protocol being managed, not the protocol used for management. If a constraint is not specific to a management protocol, then it should be left to Data Model designers of that protocol to determine how to handle it. For example:

VLAN identifiers (VLAN IDs) are defined by the standard to range from 1 to 4094. Therefore, a YANG "vlan-id" definition representing the 12-bit VLAN ID used in the VLAN Tag header uses a range of "1..4094".

Monitoring the Device Consider whether device performance will be affected by the number of protocol entities being instantiated on the device. Designers of an Information Model should include information, accessible at runtime, about the maximum number of instances an implementation can support, the current number of instances, and the expected behavior when the current instances exceed the capacity of the implementation or the capacity of the device.

Monitoring the Network Consider whether network performance will be affected by the number of protocol entities being deployed. Consider the capability of determining the operational activity, such as the number of messages in and the messages out, the number of received messages rejected due to format Problems, and the expected behaviors when a malformed message is received. What are the principal performance factors that need to be considered when measuring the operational performance of a network built using the protocol? Is it important to measure setup times, end-to-end connectivity, hop-by-hop connectivity, or network throughput?

Monitoring the Service What are the principal performance factors that need to be considered when measuring the performance of a service using the protocol? Is it important to measure application-specific throughput, client-server associations, end-to-end application quality, service interruptions, or user experience (UX)? Note that monitoring a service must consider the utility to the user. This includes responsiveness, smoothness (absence of jitter), throughput, and other "quality of experience" factors.

Security Management Protocol Designers should consider how to monitor and manage security aspects and vulnerabilities of the New Protocol or Protocol Extension. Likewise, Protocol Designers should consider how some operations (e.g., logging) might include privacy-sensitive information, which ought to be controlled to avoid access by unauthorized entities. Protocol Designers should consider whether a system automatically notifies operators of every event occurrence as default behavior or should define an operator-defined threshold to control when a notification is sent to an operator. Protocol Designers should assess whether and which statistics need to be collected about the operation of the New Protocol that might be useful for detecting attacks (e.g., the receipt of malformed messages, messages out of order, or messages with invalid timestamps). If such statistics are collected, care should be taken to evaluate whether it is important to count them separately for each sender to help identify the source of attacks. Security-oriented manageability topics may include risks of insufficient monitoring, regulatory issues with missing audit trails, log capacity limits, and security exposures in recommended management mechanisms. Protocol Designers should consider security threats that may be introduced by management operations. For example:

Control and Provisioning of Wireless Access Points (CAPWAP) breaks the structure of monolithic Access Points (APs) into Access Controllers and Wireless Termination Points (WTPs). By using a control protocol or management protocol, internal information that was previously not accessible is now exposed over the network and to management applications and may become a source of potential security threats.

The granularity of access control needed on management interfaces needs to match operational needs. Typical requirements are a role-based access control model and the principle of least privilege, where a user can be given only the minimum access necessary to perform a required task. Some operators wish to do consistency checks of Access Control Lists (ACLs) across devices. Protocol Designers should consider Information Models to promote comparisons across devices and across vendors to permit checking the consistency of security configurations. Protocol Designers should consider how to provide a secure transport, authentication, identity, and access control that integrates well with existing key and credential management infrastructure. It is a good idea to start with defining the threat model for the protocol, and from that deducing what is required. Protocol Designers should consider how ACLs are maintained and updated. Notifications (e.g., syslog messages) might already exist, or can be defined, to alert operators to the conditions identified in the Security Considerations for the New Protocol or Protocol Extension. The syslog should also record events, such as failed logins, but it must be secured. For example:

All commands entered by operators can be logged via syslog to provide an audit trail. Authentication events, including logins, logouts, and failed login attempts, can be recorded using the Secure Shell (SSH) Protocol , capturing the source of each connection.

Different management protocols use different assumptions about message security and data-access controls. A Protocol Designer that recommends using different protocols should consider how security will be applied in a balanced manner across multiple management interfaces. SNMP authority levels and policy are data-oriented, while CLI authority levels and policy are usually command-oriented (i.e., task-oriented). Depending on the management function, sometimes data-oriented or task-oriented approaches make more sense. Protocol Designers should consider both data-oriented and task-oriented authority levels and policy. Refer also to for more details on access control types and rules.

Operational and Management Tooling Considerations The operational community's ability to effectively adopt and use new specifications is significantly influenced by the availability and adaptability of appropriate tooling. In this context, "tools" refers to software systems or utilities used by network operators to deploy, configure, monitor, troubleshoot, and manage networks or network protocols in real-world operational environments. While the introduction of a new specification does not automatically mandate the development of entirely new tools, careful consideration must be given to how existing tools can be leveraged or extended to support the management and operation of these new specifications. The workshop highlighted a consistent theme applicable beyond network management protocols: the "ease of use" and adaptability of existing tools are critical factors for successful adoption. Therefore, a new specification should provide examples using existing, common tooling, or running code that demonstrate how to perform key operational tasks. Specifically, the following tooling-related aspects should be considered in the operational considerations section, prioritizing the adaptation of existing tools:

Leveraging Existing Tooling: Before considering new tools, assess whether existing tooling, such as monitoring systems, logging platforms, configuration management systems, and/or orchestration frameworks, can be adapted to support the new specification. This may involve developing plugins, modules, or drivers that enable these tools to interact with the new specification.
Extending Existing Tools: Identify areas where existing tools can be extended to provide the necessary visibility and control over the new specification. For example, if a new transport protocol is introduced, consider whether existing network monitoring tools can be extended to track its performance metrics or whether existing security tools can be adapted to analyze its traffic patterns.
New Tools: Only when existing tools are demonstrably inadequate for managing and operating the elements of the new specification should the development of new tools be considered. In such cases, carefully define the specific requirements for these new tools, focusing on the functionalities that cannot be achieved through adaptation or extension of existing solutions.
IETF Hackathons for Manageability Testing: IETF Hackathons provide an opportunity to test the functionality, interoperability, and manageability of New Protocols or Protocol Extensions. These events can be specifically leveraged to assess the operational (including manageability) implications of a New Protocol or Protocol Extension by focusing tasks on:
- Adapting existing tools to interact with the new specification.
- Developing example management scripts or modules for existing management platforms.
- Testing the specification's behavior under various operational conditions.
- Identifying potential tooling gaps and areas for improvement.
- Creating example flows and use cases for manageability.
Open Source for Tooling: If new tools are deemed necessary, or if significant adaptations to existing tools are required, prioritize open source development with community involvement. Open source tools lower the barrier to entry, encourage collaboration, and provide operators with the flexibility to customize and extend the tools to meet their specific needs.

AI Tooling Considerations With the increasing adoption of Artificial Intelligence (AI) in network operations, Protocol Designers must consider the implication such functions may have on New Protocols and Protocol Extensions. AI models often require extensive and granular data for training and inference, requiring efficient, scalable, and secure mechanisms for telemetry, logging, and state information collection. Protocol Designers should anticipate that AI-powered management tools may generate frequent and potentially aggressive querying patterns on network devices and controllers. Therefore, protocols should be designed with Data Models and mechanisms intended to prevent overload from automated interactions, such as subscription to YANG notifications , which bounds that load and provides change semantics rather than repeated snapshots, while also accounting for AI-specific security considerations such as data integrity and protection against adversarial attacks on management interfaces. These considerations are also relevant to Performance Management (Section ) and Security Management (Section ).

IANA Considerations This document does not have any IANA actions required.

Operational Considerations There are no new operations or manageability requirements introduced by this document. Although this document focuses on operations and manageability guidance, it does not define a New Protocol, a Protocol Extension, or an architecture.

Security Considerations This document provides guidelines for Protocol Designers for considering manageability and operations. It introduces no new security concerns. Protocol Designers seeking guidance on security-related management considerations for New Protocols or Protocol Extensions, such as monitoring, access control, and secure transport, should refer to .

References Normative References Guide for Internet Standards Writers This document is a guide for Internet standard writers. It defines those characteristics that make standards coherent, unambiguous, and easy to interpret. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. YANG Data Structure Extensions This document describes YANG mechanisms for defining abstract data structures with YANG. YANG Tree Diagrams This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language. Some Key Terms for Network Fault and Problem Management This document sets out some terms that are fundamental to a common understanding of network fault and problem management within the IETF. The purpose of this document is to bring clarity to discussions and other work related to network fault and problem management -- in particular, to YANG data models and management protocols that report, make visible, or manage network faults and problems. Active and Passive Metrics and Methods (with Hybrid Types In-Between) This memo provides clear definitions for Active and Passive performance assessment. The construction of Metrics and Methods can be described as either "Active" or "Passive". Some methods may use a subset of both Active and Passive attributes, and we refer to these as "Hybrid Methods". This memo also describes multiple dimensions to help evaluate new methods as they emerge. Informative References Operations and Management Review Checklist Ops Directorate (opsdir) Performance Metrics Directorate (perfmetrdir) IETF Hackathons IETF NICCS Glossary Recommendations on Filtering of IPv4 Packets Containing IPv4 Options This document provides advice on the filtering of IPv4 packets based on the IPv4 options they contain. Additionally, it discusses the operational and interoperability implications of dropping packets based on the IP options they contain. Guidelines for Considering Operations and Management of New Protocols and Protocol Extensions New protocols or protocol extensions are best designed with due consideration of the functionality needed to operate and manage the protocols. Retrofitting operations and management is sub-optimal. The purpose of this document is to provide guidance to authors and reviewers of documents that define new protocols or protocol extensions regarding aspects of operations and management that should be considered. This memo provides information for the Internet community. Guidelines for Writing RFC Text on Security Considerations All RFCs are required to have a Security Considerations section. Historically, such sections have been relatively weak. This document provides guidelines to RFC authors on how to write a good Security Considerations section. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Security Considerations for Transient Numeric Identifiers Employed in Network Protocols Poor selection of transient numerical identifiers in protocols such as the TCP/IP suite has historically led to a number of attacks on implementations, ranging from Denial of Service (DoS) or data injection to information leakages that can be exploited by pervasive monitoring. Due diligence in the specification of transient numeric identifiers is required even when cryptographic techniques are employed, since these techniques might not mitigate all the associated issues. This document formally updates RFC 3552, incorporating requirements for transient numeric identifiers, to prevent flaws in future protocols and implementations. Guidelines for Considering New Performance Metric Development This document describes a framework and a process for developing Performance Metrics of protocols and applications transported over IETF-specified protocols. These metrics can be used to characterize traffic on live networks and services. This memo documents an Internet Best Current Practice. Key words for use in RFCs to Indicate Requirement Levels In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. On the Difference between Information Models and Data Models There has been ongoing confusion about the differences between Information Models and Data Models for defining managed objects in network management. This document explains the differences between these terms by analyzing how existing network management model specifications (from the IETF and other bodies such as the International Telecommunication Union (ITU) or the Distributed Management Task Force (DMTF)) fit into the universe of Information Models and Data Models. This memo documents the main results of the 8th workshop of the Network Management Research Group (NMRG) of the Internet Research Task Force (IRTF) hosted by the University of Texas at Austin. This memo provides information for the Internet community. Guidelines for the Use of the "OAM" Acronym in the IETF At first glance, the acronym "OAM" seems to be well-known and well-understood. Looking at the acronym a bit more closely reveals a set of recurring problems that are revisited time and again. This document provides a definition of the acronym "OAM" (Operations, Administration, and Maintenance) for use in all future IETF documents that refer to OAM. There are other definitions and acronyms that will be discussed while exploring the definition of the constituent parts of the "OAM" term. This memo documents an Internet Best Current Practice. Guidelines for Characterizing the Term "OAM" As the IETF continues to produce and standardize different Operations, Administration, and Maintenance (OAM) protocols and technologies, various qualifiers and modifiers are prepended to the OAM abbreviation. While, at first glance, the most used qualifiers appear to be well understood, the same qualifier may be interpreted differently in different contexts. A case in point is the qualifiers "in-band" and "out-of-band", which have their origins in the radio lexicon, and which have been extrapolated into other communication networks. This document recommends not to use these two terms when referring to OAM. This document considers some common qualifiers and modifiers that are prepended, within the context of packet networks, to the OAM abbreviation and lays out guidelines for their use in IETF documents. This document extends RFC 6291 by adding to the guidelines for the use of the term "OAM" with qualifiers. It does not modify any part of RFC 6291. A YANG Data Model for Network Incident Management CMCC Telefonica Huawei Ciena This document defines a YANG Module for the network incident lifecycle management. This YANG module is meant to provide a standard way to report, diagnose, and help reduce troubleshooting tickets and resolve network incidents for the sake of network service health and probable root cause analysis. DNS over CoAP (DoC) This document defines a protocol for exchanging DNS queries (OPCODE 0) over the Constrained Application Protocol (CoAP). These CoAP messages can be protected by (D)TLS-Secured CoAP or Object Security for Constrained RESTful Environments (OSCORE) to provide encrypted DNS message exchange for constrained devices in the Internet of Things (IoT). Cryptographic Algorithms for Internet of Things (IoT) Devices Arm Limited Nordic Semiconductor Openchip & Software Technologies, S.L. The SUIT manifest, as defined in "A Manifest Information Model for Firmware Updates in Internet of Things (IoT) Devices" (RFC 9124), provides a flexible and extensible format for describing how firmware and software updates are to be fetched, verified, decrypted, and installed on resource-constrained devices. To ensure the security of these update processes, the manifest relies on cryptographic algorithms for functions such as digital signature verification, integrity checking, and confidentiality. This document defines cryptographic algorithm profiles for use with the Software Updates for Internet of Things (SUIT) manifest. These profiles specify sets of algorithms to promote interoperability across implementations. Given the diversity of IoT deployments and the evolving cryptographic landscape, algorithm agility is essential. This document groups algorithms into named profiles to accommodate varying levels of device capabilities and security requirements. These profiles support the use cases laid out in the SUIT architecture, published in "A Firmware Update Architecture for Internet of Things" (RFC 9019). Proportional Rate Reduction (PRR) This document specifies a Standards Track version of the Proportional Rate Reduction (PRR) algorithm that obsoletes the Experimental version described in RFC 6937. PRR regulates the amount of data sent by TCP or other transport protocols during fast recovery. PRR accurately regulates the actual flight size through recovery such that at the end of recovery it will be as close as possible to the slow start threshold (ssthresh), as determined by the congestion control algorithm. Peer-to-Peer Streaming Peer Protocol (PPSPP) The Peer-to-Peer Streaming Peer Protocol (PPSPP) is a protocol for disseminating the same content to a group of interested parties in a streaming fashion. PPSPP supports streaming of both prerecorded (on- demand) and live audio/video content. It is based on the peer-to- peer paradigm, where clients consuming the content are put on equal footing with the servers initially providing the content, to create a system where everyone can potentially provide upload bandwidth. It has been designed to provide short time-till-playback for the end user and to prevent disruption of the streams by malicious peers. PPSPP has also been designed to be flexible and extensible. It can use different mechanisms to optimize peer uploading, prevent freeriding, and work with different peer discovery schemes (centralized trackers or Distributed Hash Tables). It supports multiple methods for content integrity protection and chunk addressing. Designed as a generic protocol that can run on top of various transport protocols, it currently runs on top of UDP using Low Extra Delay Background Transport (LEDBAT) for congestion control. Registration Data Access Protocol (RDAP) Extension for Geofeed Data This document defines a new Registration Data Access Protocol (RDAP) extension, "geofeed1", for indicating that an RDAP server hosts geofeed URLs for its IP network objects. It also defines a new media type and a new link relation type for the associated link objects included in responses. Distribution of Link-State and Traffic Engineering Information Using BGP In many environments, a component external to a network is called upon to perform computations based on the network topology and the current state of the connections within the network, including Traffic Engineering (TE) information. This is information typically distributed by IGP routing protocols within the network. This document describes a mechanism by which link-state and TE information can be collected from networks and shared with external components using the BGP routing protocol. This is achieved using a BGP Network Layer Reachability Information (NLRI) encoding format. The mechanism applies to physical and virtual (e.g., tunnel) IGP links. The mechanism described is subject to policy control. Applications of this technique include Application-Layer Traffic Optimization (ALTO) servers and Path Computation Elements (PCEs). This document obsoletes RFC 7752 by completely replacing that document. It makes some small changes and clarifications to the previous specification. This document also obsoletes RFC 9029 by incorporating the updates that it made to RFC 7752. A YANG Data Model for In Situ Operations, Administration, and Maintenance (IOAM) Integrity-Protected Options University of Liege Huawei In Situ Operations, Administration, and Maintenance (IOAM) is an example of an on-path hybrid measurement method to collect operational and telemetry information. The collected data may then be exported to systems that will use it to, e.g., monitor, measure, or (re)configure the network. Integrity Protection of In Situ Operations, Administration, and Maintenance (IOAM) Data Fields (RFC YYYY) defines IOAM Options with integrity protection, also called Integrity-Protected Options. This document defines a YANG data model for the management of these Integrity-Protected Options. The document also defines an IANA-maintained YANG module for IOAM Integrity Protection Methods. What Makes for a Successful Protocol? The Internet community has specified a large number of protocols to date, and these protocols have achieved varying degrees of success. Based on case studies, this document attempts to ascertain factors that contribute to or hinder a protocol's success. It is hoped that these observations can serve as guidance for future protocol work. This memo provides information for the Internet community. BGP Route Flap Damping A usage of the BGP routing protocol is described which is capable of reducing the routing traffic passed on to routing peers and therefore the load on these peers without adversely affecting route convergence time for relatively stable routes. [STANDARDS-TRACK] Architectural Principles of the Internet The Internet and its architecture have grown in evolutionary fashion from modest beginnings, rather than from a Grand Plan. While this process of evolution is one of the main reasons for the technology's success, it nevertheless seems useful to record a snapshot of the current principles of the Internet architecture. This is intended for general guidance and general interest, and is in no way intended to be a formal or invariant reference model. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. Computing TCP's Retransmission Timer This document defines the standard algorithm that Transmission Control Protocol (TCP) senders are required to use to compute and manage their retransmission timer. It expands on the discussion in Section 4.2.3.1 of RFC 1122 and upgrades the requirement of supporting the algorithm from a SHOULD to a MUST. This document obsoletes RFC 2988. [STANDARDS-TRACK] Internet X.509 Public Key Infrastructure -- Algorithm Identifiers for the Module-Lattice-Based Digital Signature Algorithm (ML-DSA) Digital signatures are used within X.509 certificates and Certificate Revocation Lists (CRLs), and to sign messages. This document specifies the conventions for using FIPS 204, the Module-Lattice-Based Digital Signature Algorithm (ML-DSA) in Internet X.509 certificates and CRLs. The conventions for the associated signatures, subject public keys, and private key are also described. Planning for Protocol Adoption and Subsequent Transitions Over the many years since the introduction of the Internet Protocol, we have seen a number of transitions throughout the protocol stack, such as deploying a new protocol, or updating or replacing an existing protocol. Many protocols and technologies were not designed to enable smooth transition to alternatives or to easily deploy extensions; thus, some transitions, such as the introduction of IPv6, have been difficult. This document attempts to summarize some basic principles to enable future transitions, and it also summarizes what makes for a good transition plan. Network Time Protocol Version 4: Protocol and Algorithms Specification The Network Time Protocol (NTP) is widely used to synchronize computer clocks in the Internet. This document describes NTP version 4 (NTPv4), which is backwards compatible with NTP version 3 (NTPv3), described in RFC 1305, as well as previous versions of the protocol. NTPv4 includes a modified protocol header to accommodate the Internet Protocol version 6 address family. NTPv4 includes fundamental improvements in the mitigation and discipline algorithms that extend the potential accuracy to the tens of microseconds with modern workstations and fast LANs. It includes a dynamic server discovery scheme, so that in many cases, specific server configuration is not required. It corrects certain errors in the NTPv3 design and implementation and includes an optional extension mechanism. Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification This memo describes version 1 of RSVP, a resource reservation setup protocol designed for an integrated services Internet. RSVP provides receiver-initiated setup of resource reservations for multicast or unicast data flows, with good scaling and robustness properties. [STANDARDS-TRACK] IP Router Alert Option This memo describes a new IP Option type that alerts transit routers to more closely examine the contents of an IP packet. [STANDARDS-TRACK] IPv6 Router Alert Option This memo describes a new IPv6 Hop-by-Hop Option type that alerts transit routers to more closely examine the contents of an IP datagram. [STANDARDS-TRACK] Deprecation of the IPv6 Router Alert Option for New Protocols This document deprecates the IPv6 Router Alert option. Protocols that use the IPv6 Router Alert option may continue to do so, even in future versions. However, new protocols that are standardized in the future must not use the IPv6 Router Alert option. This document updates RFC 2711. Design Considerations for Protocol Extensions This document discusses architectural issues related to the extensibility of Internet protocols, with a focus on design considerations. It is intended to assist designers of both base protocols and extensions. Case studies are included. A companion document, RFC 4775 (BCP 125), discusses procedures relating to the extensibility of IETF protocols. This document is not an Internet Standards Track specification; it is published for informational purposes. Limited Domains and Internet Protocols There is a noticeable trend towards network behaviors and semantics that are specific to a particular set of requirements applied within a limited region of the Internet. Policies, default parameters, the options supported, the style of network management, and security requirements may vary between such limited regions. This document reviews examples of such limited domains (also known as controlled environments), notes emerging solutions, and includes a related taxonomy. It then briefly discusses the standardization of protocols for limited domains. Finally, it shows the need for a precise definition of "limited domain membership" and for mechanisms to allow nodes to join a domain securely and to find other members, including boundary nodes. This document is the product of the research of the authors. It has been produced through discussions and consultation within the IETF but is not the product of IETF consensus. Specifying New Congestion Control Algorithms RFC 5033 discusses the principles and guidelines for standardizing new congestion control algorithms. This document obsoletes RFC 5033 to reflect changes in the congestion control landscape by providing a framework for the development and assessment of congestion control mechanisms, promoting stability across diverse network paths. This document seeks to ensure that proposed congestion control algorithms operate efficiently and without harm when used in the global Internet. It emphasizes the need for comprehensive testing and validation to prevent adverse interactions with existing flows. Domain names - concepts and facilities This RFC is the revised basic definition of The Domain Name System. It obsoletes RFC-882. This memo describes the domain style names and their used for host address look up and electronic mail forwarding. It discusses the clients and servers in the domain name system and the protocol used between them. Simple Mail Transfer Protocol This document is a specification of the basic protocol for Internet electronic mail transport. It consolidates, updates, and clarifies several previous documents, making all or parts of most of them obsolete. It covers the SMTP extension mechanisms and best practices for the contemporary Internet, but does not provide details about particular extensions. Although SMTP was designed as a mail transport and delivery protocol, this specification also contains information that is important to its use as a "mail submission" protocol for "split-UA" (User Agent) mail reading systems and mobile environments. [STANDARDS-TRACK] Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs) One desirable application of Bidirectional Forwarding Detection (BFD) is to detect a Multiprotocol Label Switching (MPLS) Label Switched Path (LSP) data plane failure. LSP Ping is an existing mechanism for detecting MPLS data plane failures and for verifying the MPLS LSP data plane against the control plane. BFD can be used for the former, but not for the latter. However, the control plane processing required for BFD Control packets is relatively smaller than the processing required for LSP Ping messages. A combination of LSP Ping and BFD can be used to provide faster data plane failure detection and/or make it possible to provide such detection on a greater number of LSPs. This document describes the applicability of BFD in relation to LSP Ping for this application. It also describes procedures for using BFD in this environment. [STANDARDS-TRACK] Packetization Layer Path MTU Discovery for Datagram Transports This document specifies Datagram Packetization Layer Path MTU Discovery (DPLPMTUD). This is a robust method for Path MTU Discovery (PMTUD) for datagram Packetization Layers (PLs). It allows a PL, or a datagram application that uses a PL, to discover whether a network path can support the current size of datagram. This can be used to detect and reduce the message size when a sender encounters a packet black hole. It can also probe a network path to discover whether the maximum packet size can be increased. This provides functionality for datagram transports that is equivalent to the PLPMTUD specification for TCP, specified in RFC 4821, which it updates. It also updates the UDP Usage Guidelines to refer to this method for use with UDP datagrams and updates SCTP. The document provides implementation notes for incorporating Datagram PMTUD into IETF datagram transports or applications that use datagram transports. This specification updates RFC 4960, RFC 4821, RFC 6951, RFC 8085, and RFC 8261. IP Fragmentation Considered Fragile This document describes IP fragmentation and explains how it introduces fragility to Internet communication. This document also proposes alternatives to IP fragmentation and provides recommendations for developers and network operators. Indicators of Compromise (IoCs) and Their Role in Attack Defence Cyber defenders frequently rely on Indicators of Compromise (IoCs) to identify, trace, and block malicious activity in networks or on endpoints. This document reviews the fundamentals, opportunities, operational limitations, and recommendations for IoC use. It highlights the need for IoCs to be detectable in implementations of Internet protocols, tools, and technologies -- both for the IoCs' initial discovery and their use in detection -- and provides a foundation for approaches to operational challenges in network security. qlog: Structured Logging for Network Protocols Akamai Meta Cloudflare qlog provides extensible structured logging for network protocols, allowing for easy sharing of data that benefits common debug and analysis methods and tooling. This document describes key concepts of qlog: formats, files, traces, events, and extension points. This definition includes the high-level log file schemas, and generic event schemas. Requirements and guidelines for creating protocol- specific event schemas are also presented. All schemas are defined independent of serialization format, allowing logs to be represented in various ways such as JSON, CSV, or protobuf. Note to Readers Note to RFC editor: Please remove this section before publication. Feedback and discussion are welcome at https://github.com/quicwg/qlog (https://github.com/quicwg/qlog). Readers are advised to refer to the "editor's draft" at that URL for an up-to-date version of this document. QUIC: A UDP-Based Multiplexed and Secure Transport This document defines the core of the QUIC transport protocol. QUIC provides applications with flow-controlled streams for structured communication, low-latency connection establishment, and network path migration. QUIC includes security measures that ensure confidentiality, integrity, and availability in a range of deployment circumstances. Accompanying documents describe the integration of TLS for key negotiation, loss detection, and an exemplary congestion control algorithm. The Transport Layer Security (TLS) Protocol Version 1.3 This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery. This document obsoletes RFC 8446, which specified TLS 1.3. This document obsoletes RFC 5246 (specifying TLS 1.2) and RFCs 5077, 6961, 7627, and 8422, all of which pertain to TLS 1.2 or earlier, and updates RFCs 5705 and 6066. This document also specifies new requirements for TLS 1.2 implementations. TLS Encrypted Client Hello This document describes a mechanism in Transport Layer Security (TLS) for encrypting a message under a server public key. DNS Queries over HTTPS (DoH) This document defines a protocol for sending DNS queries and getting DNS responses over HTTPS. Each DNS query-response pair is mapped into an HTTP exchange. Security Operations Fundamentals and Guidance UK National Cyber Security Centre UK National Cyber Security Centre Security operators are responsible for detecting malicious activity, responding to threats and defending their networks and systems from cyber attacks. Security operations are commonly entwined with other operational and management priorities to ensure that both security and operational priorities are considered holistically. With security operators being a crucial part of operation, management and security of the network, it is valuable to give consideration to them during the design of new protocols. This document builds upon draft-ietf-opsawg-rfc5706bis, describing the fundamentals of security operations to provide a foundation for considerations for protocol design and guidance. This document also describes how security operations considerations can be most usefully included in other IETF documents. Matching of Language Tags This document describes a syntax, called a "language-range", for specifying items in a user's list of language preferences. It also describes different mechanisms for comparing and matching these to language tags. Two kinds of matching mechanisms, filtering and lookup, are defined. Filtering produces a (potentially empty) set of language tags, whereas lookup produces a single language tag. Possible applications include language negotiation or content selection. This document, in combination with RFC 4646, replaces RFC 3066, which replaced RFC 1766. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Tags for Identifying Languages This document describes the structure, content, construction, and semantics of language tags for use in cases where it is desirable to indicate the language used in an information object. It also describes how to register values for use in language tags and the creation of user-defined extensions for private interchange. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Terminology Used in Internationalization in the IETF This document provides a list of terms used in the IETF when discussing internationalization. The purpose is to help frame discussions of internationalization in the various areas of the IETF and to help introduce the main concepts to IETF participants. This memo documents an Internet Best Current Practice. Network Configuration Protocol (NETCONF) The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK] An Overview of the IETF Network Management Standards This document gives an overview of the IETF network management standards and summarizes existing and ongoing development of IETF Standards Track network management protocols and data models. The document refers to other overview documents, where they exist and classifies the standards for easy orientation. The purpose of this document is, on the one hand, to help system developers and users to select appropriate standard management protocols and data models to address relevant management needs. On the other hand, the document can be used as an overview and guideline by other Standard Development Organizations or bodies planning to use IETF management technologies and data models. This document does not cover Operations, Administration, and Maintenance (OAM) technologies on the data-path, e.g., OAM of tunnels, MPLS Transport Profile (MPLS-TP) OAM, and pseudowire as well as the corresponding management models. This document is not an Internet Standards Track specification; it is published for informational purposes. BGP Monitoring Protocol (BMP) This document defines the BGP Monitoring Protocol (BMP), which can be used to monitor BGP sessions. BMP is intended to provide a convenient interface for obtaining route views. Prior to the introduction of BMP, screen scraping was the most commonly used approach to obtaining such views. The design goals are to keep BMP simple, useful, easily implemented, and minimally service affecting. BMP is not suitable for use as a routing protocol. Subscription to YANG Notifications This document defines a YANG data model and associated mechanisms enabling subscriber-specific subscriptions to a publisher's event streams. Applying these elements allows a subscriber to request and receive a continuous, customized feed of publisher-generated information. Subscription to YANG Notifications for Datastore Updates This document describes a mechanism that allows subscriber applications to request a continuous and customized stream of updates from a YANG datastore. Providing such visibility into updates enables new capabilities based on the remote mirroring and monitoring of configuration and operational state. A YANG Data Model for Alarm Management This document defines a YANG module for alarm management. It includes functions for alarm-list management, alarm shelving, and notifications to inform management systems. There are also operations to manage the operator state of an alarm and administrative alarm procedures. The module carefully maps to relevant alarm standards. Network Telemetry Framework Network telemetry is a technology for gaining network insight and facilitating efficient and automated network management. It encompasses various techniques for remote data generation, collection, correlation, and consumption. This document describes an architectural framework for network telemetry, motivated by challenges that are encountered as part of the operation of networks and by the requirements that ensue. This document clarifies the terminology and classifies the modules and components of a network telemetry system from different perspectives. The framework and taxonomy help to set a common ground for the collection of related work and provide guidance for related technique and standard developments. The YANG 1.1 Data Modeling Language YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF). RESTCONF Protocol This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF). Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information This document specifies the IP Flow Information Export (IPFIX) protocol, which serves as a means for transmitting Traffic Flow information over the network. In order to transmit Traffic Flow information from an Exporting Process to a Collecting Process, a common representation of flow data and a standard means of communicating them are required. This document describes how the IPFIX Data and Template Records are carried over a number of transport protocols from an IPFIX Exporting Process to an IPFIX Collecting Process. This document obsoletes RFC 5101. The Syslog Protocol This document describes the syslog protocol, which is used to convey event notification messages. This protocol utilizes a layered architecture, which allows the use of any number of transport protocols for transmission of syslog messages. It also provides a message format that allows vendor-specific extensions to be provided in a structured way. This document has been written with the original design goals for traditional syslog in mind. The need for a new layered specification has arisen because standardization efforts for reliable and secure syslog extensions suffer from the lack of a Standards-Track and transport-independent RFC. Without this document, each other standard needs to define its own syslog packet format and transport mechanism, which over time will introduce subtle compatibility issues. This document tries to provide a foundation that syslog extensions can build on. This layered architecture approach also provides a solid basis that allows code to be written once for each syslog feature rather than once for each transport. [STANDARDS-TRACK] YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF) YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK] Guidelines for Authors and Reviewers of Documents Containing YANG Data Models This document provides guidelines for authors and reviewers of specifications containing YANG data models, including IANA-maintained YANG modules. Recommendations and procedures are defined, which are intended to increase interoperability and usability of Network Configuration Protocol (NETCONF) and RESTCONF protocol implementations that utilize YANG modules. This document obsoletes RFC 8407; it also updates RFC 8126 by providing additional guidelines for writing the IANA considerations for RFCs that specify IANA-maintained YANG modules. YANG Module Classification The YANG data modeling language is currently being considered for a wide variety of applications throughout the networking industry at large. Many standards development organizations (SDOs), open-source software projects, vendors, and users are using YANG to develop and publish YANG modules for a wide variety of applications. At the same time, there is currently no well-known terminology to categorize various types of YANG modules. A consistent terminology would help with the categorization of YANG modules, assist in the analysis of the YANG data modeling efforts in the IETF and other organizations, and bring clarity to the YANG- related discussions between the different groups. This document describes a set of concepts and associated terms to support consistent classification of YANG modules. A YANG Network Data Model for Layer 3 VPNs As a complement to the Layer 3 Virtual Private Network Service Model (L3SM), which is used for communication between customers and service providers, this document defines an L3VPN Network Model (L3NM) that can be used for the provisioning of Layer 3 Virtual Private Network (L3VPN) services within a service provider network. The model provides a network-centric view of L3VPN services. The L3NM is meant to be used by a network controller to derive the configuration information that will be sent to relevant network devices. The model can also facilitate communication between a service orchestrator and a network controller/orchestrator. A YANG Network Data Model for Layer 2 VPNs This document defines an L2VPN Network Model (L2NM) that can be used to manage the provisioning of Layer 2 Virtual Private Network (L2VPN) services within a network (e.g., a service provider network). The L2NM complements the L2VPN Service Model (L2SM) by providing a network-centric view of the service that is internal to a service provider. The L2NM is particularly meant to be used by a network controller to derive the configuration information that will be sent to relevant network devices. Also, this document defines a YANG module to manage Ethernet segments and the initial versions of two IANA-maintained modules that include a set of identities of BGP Layer 2 encapsulation types and pseudowire types. Service Models Explained The IETF has produced many modules in the YANG modeling language. The majority of these modules are used to construct data models to model devices or monolithic functions. A small number of YANG modules have been defined to model services (for example, the Layer 3 Virtual Private Network Service Model (L3SM) produced by the L3SM working group and documented in RFC 8049). This document describes service models as used within the IETF and also shows where a service model might fit into a software-defined networking architecture. Note that service models do not make any assumption of how a service is actually engineered and delivered for a customer; details of how network protocols and devices are engineered to deliver a service are captured in other modules that are not exposed through the interface between the customer and the provider. YANG Data Model for L3VPN Service Delivery This document defines a YANG data model that can be used for communication between customers and network operators and to deliver a Layer 3 provider-provisioned VPN service. This document is limited to BGP PE-based VPNs as described in RFCs 4026, 4110, and 4364. This model is intended to be instantiated at the management system to deliver the overall service. It is not a configuration model to be used directly on network elements. This model provides an abstracted view of the Layer 3 IP VPN service configuration components. It will be up to the management system to take this model as input and use specific configuration models to configure the different network elements to deliver the service. How the configuration of network elements is done is out of scope for this document. This document obsoletes RFC 8049; it replaces the unimplementable module in that RFC with a new module with the same name that is not backward compatible. The changes are a series of small fixes to the YANG module and some clarifications to the text. A YANG Data Model for Layer 2 Virtual Private Network (L2VPN) Service Delivery This document defines a YANG data model that can be used to configure a Layer 2 provider-provisioned VPN service. It is up to a management system to take this as an input and generate specific configuration models to configure the different network elements to deliver the service. How this configuration of network elements is done is out of scope for this document. The YANG data model defined in this document includes support for point-to-point Virtual Private Wire Services (VPWSs) and multipoint Virtual Private LAN Services (VPLSs) that use Pseudowires signaled using the Label Distribution Protocol (LDP) and the Border Gateway Protocol (BGP) as described in RFCs 4761 and 6624. The YANG data model defined in this document conforms to the Network Management Datastore Architecture defined in RFC 8342. Requirements for Configuration Management of IP-based Networks This memo discusses different approaches to configure networks and identifies a set of configuration management requirements for IP-based networks. This memo provides information for the Internet community. Terminology for Policy-Based Management This document is a glossary of policy-related terms. It provides abbreviations, explanations, and recommendations for use of these terms. The intent is to improve the comprehensibility and consistency of writing that deals with network policy, particularly Internet Standards documents (ISDs). This memo provides information for the Internet community. Overview of the 2002 IAB Network Management Workshop This document provides an overview of a workshop held by the Internet Architecture Board (IAB) on Network Management. The workshop was hosted by CNRI in Reston, VA, USA on June 4 thru June 6, 2002. The goal of the workshop was to continue the important dialog started between network operators and protocol developers, and to guide the IETFs focus on future work regarding network management. This report summarizes the discussions and lists the conclusions and recommendations to the Internet Engineering Task Force (IETF) community. This memo provides information for the Internet community. Unicode Format for Network Interchange The Internet today is in need of a standardized form for the transmission of internationalized "text" information, paralleling the specifications for the use of ASCII that date from the early days of the ARPANET. This document specifies that format, using UTF-8 with normalization and specific line-ending sequences. [STANDARDS-TRACK] Introduction to Accounting Management This document describes and discusses the issues involved in the design of the modern accounting systems. The field of Accounting Management is concerned with the collection the collection of resource consumption data for the purposes of capacity and trend analysis, cost allocation, auditing, and billing. This memo provides information for the Internet community. Benchmarking Methodology for Network Interconnect Devices This document is a republication of RFC 1944 correcting the values for the IP addresses which were assigned to be used as the default addresses for networking test equipment. This memo provides information for the Internet community. Framework for IP Performance Metrics The purpose of this memo is to define a general framework for particular metrics to be developed by the IETF's IP Performance Metrics effort. This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Control And Provisioning of Wireless Access Points (CAPWAP) Protocol Specification This specification defines the Control And Provisioning of Wireless Access Points (CAPWAP) Protocol, meeting the objectives defined by the CAPWAP Working Group in RFC 4564. The CAPWAP protocol is designed to be flexible, allowing it to be used for a variety of wireless technologies. This document describes the base CAPWAP protocol, while separate binding extensions will enable its use with additional wireless technologies. [STANDARDS-TRACK] The Secure Shell (SSH) Protocol Architecture The Secure Shell (SSH) Protocol is a protocol for secure remote login and other secure network services over an insecure network. This document describes the architecture of the SSH protocol, as well as the notation and terminology used in SSH protocol documents. It also discusses the SSH algorithm naming system that allows local extensions. The SSH protocol consists of three major components: The Transport Layer Protocol provides server authentication, confidentiality, and integrity with perfect forward secrecy. The User Authentication Protocol authenticates the client to the server. The Connection Protocol multiplexes the encrypted tunnel into several logical channels. Details of these protocols are described in separate documents. [STANDARDS-TRACK] Network Configuration Access Control Model The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model. This document obsoletes RFC 6536. Report from the IAB Workshop on the Next Era of Network Management Operations (NEMOPS) The "Next Era of Network Management Operations (NEMOPS)" workshop was convened by the Internet Architecture Board (IAB) from December 3-5, 2024 as a three-day online meeting. It builds on a previous 2002 workshop, the outcome of which was documented in RFC 3535, identifying 14 operator requirements for consideration in future network management protocol design and related data models, along with some recommendations for the IETF. Much has changed in the Internet's operation and technological foundations since then. The NEMOPS workshop reviewed the past outcomes and discussed any operational barriers that prevented these technologies from being widely implemented. With the industry, network operators and protocol engineers working in collaboration, the workshop developed a suggested plan of action and network management recommendations for the IETF and IRTF. Building on RFC 3535, this document provides the report of the follow-up IAB workshop on network management. Note that this document is a report on the proceedings of the workshop. The views and positions documented in this report are those of the workshop participants and do not necessarily reflect IAB views and positions.

Operational Considerations Checklist This appendix provides a concise checklist of key questions that Protocol Designers should address in the "Operational Considerations" section of their specifications. Each item references the relevant section of this document for detailed guidance. This checklist is intended for use by document authors and the working groups that develop protocol documents. A separate list of guidelines and a checklist of questions to consider when reviewing a document to evaluate whether the document address common operations and management needs is provided in . The decision to incorporate all or part of these items into their work remains with Protocol Designers and WGs themselves.

Documentation Requirements

Does the specification include an "Operational Considerations" section, placed immediately before the Security Considerations section? (, )
If one or more of the topics raised in this document is not relevant, does the section briefly explain why? ()
If there are no new operational considerations, does the section include the appropriate boilerplate with explanation? ()
If the considerations are described elsewhere in the same document, does the section summarize them and point to those sections? ()
If the considerations are documented separately, does the section give a short overview and a normative reference to that document? ()

Operational Fit

How does this protocol operate "out of the box"? ()
- What are the default values, modes, timers, and states? ()
- What is the rationale for chosen default values, especially if they affect operations or are expected to change over time? ()
What is the migration path for existing deployments? ()
- How will deployments transition from older versions or technologies? ()
- Does the protocol require infrastructure changes, and how can these be introduced? ()
What are the requirements or dependencies on other protocols and functional components? ()
What is the impact on network operation? ()
- What are the scaling implications and interactions with other protocols? ()
- What are the impacts on traffic patterns or performance (e.g., delay or jitter)? ()
- Does management traffic account for MTU constraints and avoid reliance on IP fragmentation? ()
What is the impact on Security Operations? ()
- How does deployment affect Indicators of Compromise or their availability? ()
- What logging is needed for digital forensics? ()
How can correct operation be verified? ()
- What status and health indicators does the protocol provide? ()
How are human-readable messages handled? ()
- Do messages contain codes that enable local language mapping for internationalization? ()

Management Information

What needs to be managed? ()
- What are the manageable entities (e.g., protocol endpoints, network elements, and services)? ()
Which standardized management technologies are applicable? ()
What essential information is required? (, )
- What configuration and operational (state, statistical, etc.) information is needed? ()
- Is an Information Model needed, especially if multiple Data Model representations are required? ()
- Is the model kept minimal, with each object serving a distinct purpose and no data that can be derived from other objects? ()
- What is manageable, what needs configuration, and what protocol-specific events might occur? ()
- How are configuration data, operational state, and statistics distinguished? ()
If YANG Data Models are defined, what type is appropriate? ()
- Should Device Models, Network Models, or Service Models be specified? ()

Fault Management

What Faults and events should be reported? ()
- What essential Faults, health indicators, alarms, and events should be exposed? ()
- How will Fault information be propagated? ()
How is liveness monitored? ()
- What testing and liveness detection features are built into the protocol? ()
How are Faults determined? ()
- What error counters or diagnostics help pinpoint Faults? ()
- What distinguishes faulty from correct messages? ()
How are Faults localized and contained? (, )
- Can the Probable Root Cause of a Fault be identified using management information? ()
- Can Faults be isolated or quarantined to prevent them from propagating? ()

Configuration Management

What configuration parameters are defined? ()
- What parameters need to be configurable, including their valid ranges? ()
- What information persists across reboots? ()
How is configuration managed across multiple devices? ()
- Can configuration changes be applied across several devices as a coordinated operation, with a way to back out on failure? ()
- Is there a way to dump and restore configuration? ()

Accounting Management

Is it appropriate to collect usage information for this protocol, and if so, what information should be collected? ()

Performance Management

What are the performance implications? ()
- What are the hardware/software performance impacts (e.g., CPU, memory, and forwarding)? ()
What performance information should be available? ()
- What protocol counters are defined (e.g., packets received, sent, or dropped)? ()
- What is the counter behavior at maximum values? ()
- What are the protocol limitations and behavior when limits are exceeded? ()

Security Management

What security-related monitoring is needed? ()
- What security events should be logged, and do any log entries contain privacy-sensitive information that must be controlled? ()
- What statistics help detect attacks, and what threats do management operations themselves introduce? ()
What access controls are needed on management interfaces? ()
- Do management interfaces support role-based access control and the principle of least privilege? ()
- How are ACLs maintained, updated, and verified for consistency across devices? ()
How are secure transport, authentication, identity, and key/credential management addressed for management operations? ()

Operational and Management Tooling

Can existing tooling be adapted or extended to deploy, monitor, and manage this specification before new tools are considered? ()
- Where new tooling is required, are its requirements limited to functions that adaptation or extension cannot provide? ()
- Is the management interface designed to remain stable under high-frequency automated query patterns, including those from AI-driven tools? ()

Acknowledgements The authors thank the following individuals and groups, whose efforts have helped to improve this document:

The IETF Ops Directorate (OpsDir):: The IETF OpsDir reviewer team, which has been providing document reviews for more than a decade, and its Chairs past and present: Gunter Van de Velde, Carlos Pignataro, Bo Wu, and Daniele Ceccarelli.
The Area Director (AD) championing the update:: Med Boucadair, who initiated and championed the effort to refresh RFC 5706, 15 years after its publication, building on an idea originally suggested by Carlos Pignataro.
Reviewers of this document, in roughly chronological order:: Mahesh Jethanandani, Chongfeng Xie, Alvaro Retana, Michael P., Scott Hollenbeck, Ron Bonica, Italo Busi, Brian Trammell, Aijun Wang, Richard Shockey, Tina Tsou, Lars Eggert, Joel Halpern, Johan Stenstam, Dave Thaler, Harald Alvestrand, Greg Mirsky, Marco Tiloca, Jacqueline McCall, Tim Winters, Eliot Lear, Giuseppe Fioccola, Bo Wu, Qin Wu, Saumya Dikshit, and Paul Aitken.
The document shepherd who has gone beyond normal shepherding duties to improve this document:: Alvaro Retana

Claude Opus was used to distill document content into .

The author of RFC 5706:: David Harrington
Acknowledgments from RFC 5706:: The following acknowledgments apply to RFC 5706, the predecessor of this document. Some individuals listed below as reviewers of RFC 5706 are now authors or contributors of this document.
: This document started from an earlier document edited by Adrian Farrel, which itself was based on work exploring the need for Manageability Considerations sections in all Internet-Drafts produced within the Routing Area of the IETF. That earlier work was produced by Avri Doria, Loa Andersson, and Adrian Farrel, with valuable feedback provided by Pekka Savola and Bert Wijnen.
: Some of the discussion about designing for manageability came from private discussions between Dan Romascanu, Bert Wijnen, Jürgen Schönwälder, Andy Bierman, and David Harrington.
: Thanks to reviewers who helped fashion RFC 5706, including Harald Alvestrand, Ron Bonica, Brian Carpenter, Benoît Claise, Adrian Farrel, David Kessens, Dan Romascanu, Pekka Savola, Jürgen Schönwälder, Bert Wijnen, Ralf Wolter, and Lixia Zhang.

Contributors Swisscom

thomas.graf@swisscom.com