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Operations and Management management operations operations and management ops considerations 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 document obsoletes RFC 5706, replacing it completely and updating it with new operational and management techniques and mechanisms, and introduces a requirement for an “Operational and Management Considerations” section in Internet-Drafts, before they are progressed as publication as RFCs.

TO DO LIST See the list of open issues at https://github.com/IETF-OPSAWG-WG/draft-opsarea-rfc5706bis/issues

Introduction Often when new protocols or protocol extensions are developed, not enough consideration is given to how the protocol 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 hard. This document provides guidelines to help protocol designers and working groups consider the operations and management functionality for their new IETF protocol or protocol extension at an earlier phase. This document obsoletes RFC 5706 and fully updates its content with new operational and management techniques and mechanisms, and introduces a requirement for an “Operational and Management Considerations” section in Internet-Drafts, before they are progressed for publication as an RFC. It removes outdated references and aligns with current practices, protocols, and technologies used in operating and managing network devices and services. See .

Designing for Operations and Management The operational environment and manageability of the protocol should be considered from the start when new protocols are designed. As the Internet has grown, IETF protocols have addressed a constantly growing set of needs, such as web servers, collaboration services, and applications. The number of IETF management technologies has been expanding and the IETF management strategy has been changing to address the emerging management requirements. In the past, most of the existing IETF management standards were focused on using Structure of Management Information (SMI)-based data models (MIB modules) to monitor and manage networking devices. Currently, the YANG data modeling language is recommended to monitor and manage the IETF protocols and the networking devices. Management requirements continually evolve in the IETF. Therefore, the management protocols used should track with current IETF recommendations. 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 working group (WG) that considers which security threats are relevant to their protocol, documents how threats should be mitigated, and then suggests appropriate standard protocols that could mitigate the threats. When a WG considers operation and management functionality for a protocol, the document should contain enough information for readers to understand how the protocol will be deployed and managed. 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.

This Document This document makes a distinction between "Operational Considerations" and "Management Considerations", although the two are closely related. The section on manageability is focused on management technology, such as how to utilize management protocols and how to design management data models. The operational considerations apply to operating the protocol within a network, even if there were no management protocol actively being used. The purpose of this document is to provide guidance about what to consider when thinking about the management and deployment of a new protocol, and to provide guidance about documenting the considerations. The following guidelines are designed to help writers provide a reasonably consistent format for such documentation. Separate manageability and operational considerations sections are desirable in many cases, but their structure and location are a decision that can be made from case to case. This document does not impose a solution, imply that a formal data model is needed, or imply that using a specific management protocol is mandatory. If protocol designers conclude that the technology can be managed solely by using proprietary command line interfaces (CLIs) and that no structured or standardized data model needs to be in place, this might be fine, but it is a decision that should be explicit in a manageability discussion -- that this is how the protocol will need to be operated and managed. Protocol designers should avoid having manageability pushed for a later phase of the development of the standard. 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 .

Motivation For years the IETF community has used the IETF Standard Management Framework, including the Simple Network Management Protocol , the Structure of Management Information , and MIB data models for managing new protocols. As the Internet has evolved, operators have found the reliance on one protocol and one schema language for managing all aspects of the Internet inadequate. The IESG policy to require working groups to write a MIB module to provide manageability for new protocols is being replaced by a policy that is more open to using a variety of management protocols and data models designed to achieve different goals. In 2014, the IESG wrote a statement about "Writable MIB Module" . This statement stresses that IETF working groups are encouraged to use the NETCONF/YANG standards for configuration, especially in new charters. This document provides some initial guidelines for considering operations and management in an IETF Management Framework that consists of multiple protocols and multiple data modeling languages, with an eye toward being flexible while also striving for interoperability. Fully new protocols may require significant consideration of expected operations and management, while extensions to existing, widely deployed protocols may have established de facto operations and management practices that are already well understood. Suitable management approaches may vary for different areas, working groups, 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 IETF protocol because we develop technologies and protocols to be deployed and operated in the real-world Internet. A WG may decide that its protocol does not need interoperable management or a standardized data model, but this should be a deliberate decision, not the result of omission. This document provides some guidelines for those considerations.

Background There have been a significant number of efforts, meetings, and documents that are related to Internet operations and management. Some of them are mentioned here to help protocol designers find documentation of previous efforts. Hopefully, providing these references will help the IETF avoid rehashing old discussions and reinventing old solutions. In 1988, the IAB published "IAB Recommendations for the Development of Internet Network Management Standards" , which recommended a solution that, where possible, deliberately separates modeling languages, data models, and the protocols that carry data. The goal is to allow standardized information and data models to be used by different protocols. In 2001, Operations and Management Area design teams were created to document requirements related to the configuration of IP-based networks. One output was "Requirements for Configuration Management of IP-based Networks" . In 2002, the Internet Architecture Board (IAB) held a workshop on Network Management that discussed the strengths and weaknesses of some IETF network management protocols and compared them to operational needs, especially configuration. One issue discussed was the user-unfriendliness of the binary format of SNMP and Common Open Policy Service (COPS) Usage for Policy Provisioning (COPS-PR) , and it was recommended that the IETF explore an XML-based Structure of Management Information and an XML-based protocol for configuration. Another conclusion was that the tools for event/alarm correlation and for root cause analysis and logging are not sufficient and that there is a need to support a human interface and a programmatic interface. The IETF decided to standardize aspects of the de facto standard for system-logging security and programmatic support. In 2006, the IETF discussed whether the Management Framework should be updated to accommodate multiple IETF schema languages for describing the structure of management information and multiple IETF standard protocols for performing management tasks. The IESG asked that a document be written to discuss how protocol designers and working groups should address management in this emerging multi- protocol environment. This document and some planned companion documents attempt to provide some guidelines for navigating the rapidly shifting operating and management environments. In 2014, the IESG wrote its statement on "Writable MIB Module" , as mentioned above. In 2024, the IAB hold the "Next Era of Network Management Operations (NEMOPS)" workshop , building on the previous 2002 IAB workshop. Given that much has changed in the Internet’s operation and technological foundations since the first worshop, 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 proposed plan of action and provided network management recommendations for both the IETF and IRTF.

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

• TBC
• TBC

Key Concepts, Terminology, and Technological Landscape

Terminology This document deliberately does not use the (capitalized) keywords described in RFC 2119 . RFC 2119 states the keywords must only be used where it is actually required for interoperation or to limit behavior which has potential for causing harm (e.g., limiting retransmissions). For example, they must not be used to try to impose a particular method on implementers where the method is not required for interoperability. This informational document is a set of guidelines based on current practices of **some** protocol designers and operators. This document is biased toward router operations and management and some advice may not be directly applicable to protocols with a different purpose, such as application server protocols. This document **does not** describe interoperability requirements, so the capitalized keywords from RFC 2119 do not apply here.

• CLI: Command Line Interface
• Data model: a mapping of the contents of an information model into a form that is specific to a particular type of data store or repository .
• 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. It is independent of any specific repository, software usage, protocol, or platform .
• OAM: Operations, Administration, and Maintenance .
• New protocol: includes new protocols, protocol extensions, data models, or other functionality being designed.
• Protocol designer: represents individuals and working groups involved in the development of new protocols or extensions.

Available Management Technologies The IETF has a number of standard management protocols available that are suitable for different purposes. These include:

• Syslog
• Simple Network Management Protocol - SNMP
• Network Configuration Protocol - NETCONF
• RESTCONF
• Remote Authentication Dial-In User Service - RADIUS
• DIAMETER
• IP Flow Information Export - IPFIX
• BGP Monitoring Protocol - BMP

A planned supplement to this document will discuss these protocol standards, discuss some standard information and data models for specific functionality, and provide pointers to the documents that define them.

Operational Considerations - How Will the New Protocol Fit into the Current Environment? Designers of a new protocol should carefully consider the operational aspects. To ensure that a protocol will be practical to deploy in the real world, it is not enough to merely define it very precisely in a well-written document. Operational aspects will have a serious impact on the actual success of a protocol. Such aspects include bad interactions with existing solutions, a difficult upgrade path, difficulty of debugging problems, difficulty configuring from a central database, or a complicated state diagram that operations staff will find difficult to understand. BGP flap damping is an example. It was designed to block high-frequency route flaps; however, the design did not consider the existence of BGP path exploration / slow convergence. In real operations, path exploration caused false flap damping, resulting in loss of reachability. As a result, many networks turned flap damping off.

Operations Protocol designers can analyze the operational environment and mode of work in which the new protocol or extension will work. Such an exercise need not be reflected directly by text in their document but could help in visualizing how to apply the protocol in the Internet environments where it will be deployed. A key question is how the protocol can operate "out of the box". If implementers are free to select their own defaults, the protocol needs to operate well with any choice of values. If there are sensible defaults, these need to be stated. There may be a need to support a human interface, e.g., for troubleshooting, and a programmatic interface, e.g., for automated monitoring and root cause analysis. The application programming interfaces and the human interfaces might benefit from being similar to ensure that the information exposed by these two interfaces is consistent when presented to an operator. Identifying consistent methods of determining information, such as what gets counted in a specific counter, is relevant. Protocol designers should consider what management operations are expected to be performed as a result of the deployment of the protocol -- such as whether write operations will be allowed on routers and on hosts, or whether notifications for alarms or other events will be expected.

Installation and Initial Setup Anything that can be configured can be misconfigured. "Architectural Principles of the Internet" , Section 3.8, states: "Avoid options and parameters whenever possible. Any options and parameters should be configured or negotiated dynamically rather than manually." To simplify configuration, protocol designers should consider specifying reasonable defaults, including default modes and parameters. For example, it could be helpful or necessary to specify default values for modes, timers, default state of logical control variables, default transports, and so on. Even if default values are used, it must be possible to retrieve all the actual values or at least an indication that known default values are being used. Protocol designers should consider how to enable operators to concentrate on the configuration of the network as a whole rather than on individual devices. Of course, how one accomplishes this is the hard part. It is desirable to discuss the background of chosen default values, or perhaps why a range of values makes sense. In many cases, as technology changes, the values in an RFC might make less and less sense. It is very useful 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 be expected to change over time due to increased speeds in the network, and cryptographical algorithms might be expected to change over time as older algorithms are "broken". It is extremely important to set a sensible default value for all parameters. The default value should stay on the conservative side rather than on the "optimizing performance" side (example: the initial RTT and RTTvar values of a TCP connection). For those parameters that are speed-dependent, instead of using a constant, try to set the default value as a function of the link speed or some other relevant factors. This would help reduce the chance of problems caused by technology advancement.

Migration Path If the new protocol 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. This should include coexistence with previously deployed protocols and/or previous versions of the same protocol, incompatibilities between versions, translation between versions, and side effects that might occur. Are older protocols or versions disabled, or do they coexist in the network with the new protocol? Many protocols benefit from being incrementally deployable -- operators may deploy aspects of a protocol before deploying the protocol fully.

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 elements 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. For 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.

Impact on Network Operation The introduction of a new protocol or extensions to an existing protocol may have an impact on the operation of existing networks. Protocol designers should outline such impacts (which may be positive), including scaling concerns and interactions with other protocols. For example, a new protocol that doubles the number of active, reachable addresses in use within a network might need to be considered in the light of the impact on the scalability of the interior gateway protocols operating within the network. A protocol could send active monitoring packets on the wire. If we don't pay attention, we might get very good accuracy but could send too many active monitoring packets. The protocol designer 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. The protocol designer should consider also the impact on infrastructure applications like DNS , the registries, or the size of routing tables. For example, Simple Mail Transfer Protocol (SMTP) servers use a reverse DNS lookup to filter out incoming connection requests. When Berkeley installed a new spam filter, their mail server stopped functioning because of overload of the DNS cache resolver. The impact on performance may also be noted -- increased delay or jitter in real-time traffic applications, or increased response time in client-server applications when encryption or filtering are applied. It is important to minimize the impact caused by configuration changes. 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.

Verifying Correct Operation The protocol designer should consider techniques for testing the effect that the protocol has had on the network by sending data through the network and observing its behavior (aka active monitoring). Protocol designers should consider how the correct end- to-end operation of the new protocol in the network can be tested actively and passively, and how the correct data or forwarding plane function of each network element can be verified to be working properly with the new protocol. Which metrics are of interest? Having simple protocol status and health indicators on network devices is a recommended means to check correct operation.

Management Considerations - 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 include a discussion of what needs to be managed, and how to achieve various management tasks. Where are the managers and what type of management interfaces and protocols will they need? The "write a MIB module" approach to considering management often focuses on monitoring a protocol endpoint on a single device. A MIB module document typically only considers monitoring properties observable at one end, while the document does not really cover managing the *protocol* (the coordination of multiple ends) and does not even come near managing the *service* (which includes a lot of stuff that is very far away from the box). This is exactly what operators hate -- you need to be able to manage both ends. As says, "MIB modules can often be characterized as a list of ingredients without a recipe". 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 will be managed in different deployment scales. It might be sensible to use a local management interface to manage the new protocol 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. 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. Often an individual network element is not aware 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. 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.

Interoperability Just as when deploying protocols that will inter-connect devices, management interoperability should be considered -- whether across devices from different vendors, across models from the same vendor, or across different releases of the same product. Management interoperability refers to allowing information sharing and operations between multiple devices and multiple management applications, often from different vendors. Interoperability allows for the use of third-party applications and the outsourcing of management services. Some product designers and protocol designers assume that if a device can be managed individually using a command line interface or a web page interface, that such a solution is enough. But when equipment from multiple vendors is combined into a large network, scalability of management may become a problem. It may be important to have consistency in the management interfaces so network-wide operational processes can be automated. For example, a single switch might be easily managed using an interactive web interface when installed in a single-office small business, but when, say, a fast-food company installs similar switches from multiple vendors in hundreds or thousands of individual branches and wants to automate monitoring them from a central location, monitoring vendor- and model-specific web pages would be difficult to automate. The primary goal is the ability to roll out new useful functions and services in a way in which they can be managed in a scalable manner, where one understands the network impact (as part of the total cost of operations) of that service. Getting everybody to agree on a single syntax and an associated protocol to do all management has proven to be difficult. So, management systems tend to speak whatever the boxes support, whether or not the IETF likes this. The IETF is moving from support for one schema language for modeling the structure of management information (Structure of Management Information Version 2 (SMIv2) ) and one simple network management protocol (Simple Network Management Protocol (SNMP) ) towards support for additional schema languages and additional management protocols suited to different purposes. Other Standard Development Organizations (e.g., the Distributed Management Task Force - DMTF, the Tele-Management Forum - TMF) also define schemas and protocols for management and these may be more suitable than IETF schemas and protocols in some cases. Some of the alternatives being considered include:

• XML Schema Definition

and

• NETCONF Configuration Protocol
• the IP Flow Information Export (IPFIX) Protocol ) for usage accounting
• the syslog protocol for logging

Interoperability needs to be considered on the syntactic level and the semantic level. While it can be irritating and time-consuming, application designers, including operators who write their own scripts, can make their processing conditional to accommodate syntactic differences across vendors, models, or releases of product. Semantic differences are much harder to deal with on the manager side -- once you have the data, its meaning is a function of the managed entity. Information models are helpful to try to focus interoperability on the semantic level -- they establish standards for what information should be gathered and how gathered information might be used, regardless of which management interface carries the data or which vendor produces the product. The use of an information model might help improve the ability of operators to correlate messages in different protocols where the data overlaps, such as a syslog message and an SNMP notification about the same event. An information model might identify which error conditions should be counted separately, and which error conditions can be counted together in a single counter. Then, whether the counter is gathered via SNMP, a CLI command, or a syslog message, the counter will have the same meaning. Protocol designers should consider which information might be useful for managing the new protocol or protocol extensions.

IMs and DMs conceptual/abstract model | for designers and operators +----------+---------+ | | | DM DM DM --> concrete/detailed model for implementers Information Models and Data Models ]]>

Protocol designers may decide an information model or data model would be appropriate for managing the new protocol or protocol extensions. "On the Difference between Information Models and Data Models" can be helpful in determining what information to consider regarding information models (IMs), as compared to data models (DMs). Information models should come from the protocol WGs and include lists of events, counters, and configuration parameters that are relevant. There are a number of information models contained in protocol WG RFCs. Some examples:

• - Policy Core Information Model version 1
• - An Informal Management Model for Diffserv Routers
• - Policy Core Information Model Extensions
• - IPsec Configuration Policy Information Model
• - Policy Quality of Service Information Model
• - Information Model for Describing Network Device QoS Datapath Mechanisms
• - Printer MIB v2 (contains both an IM and a DM)

Management protocol standards and management data model standards often contain compliance clauses to ensure interoperability. Manageability considerations should include discussion of which level of compliance is expected to be supported for interoperability.

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. Although this document recommends using English text (the official language for IETF specifications) to describe an information model, including a complementary YANG module helps translate abstract concepts into implementation-specific data models. This ensures consistency between the 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. Operators find it important to be able to make a clear distinction between configuration data, operational state, and statistics. They need to determine which parameters were administratively configured and which parameters have changed since configuration as the result of mechanisms such as routing protocols or network management protocols. It is important to be able to separately fetch current configuration information, initial configuration information, operational state information, and statistics from devices; to be able to compare current state to initial state; and to compare information between devices. So, when deciding what information should exist, do not conflate multiple information elements into a single element. 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:

1. Start with a small set of essential objects and add only as further objects are needed.
2. Require that objects be essential for management.
3. Consider evidence of current use and/or utility.
4. Limit the total number of objects.
5. Exclude objects that are simply derivable from others in this or other information models.
6. Avoid causing critical sections to be heavily instrumented. A guideline is one counter per critical section per layer.
7. When using YANG to complement or define an information model, ensure that the model maintains simplicity, modularity, and clarity. Specific guidelines to consider when authoring YANG modules are described in .

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. 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) .

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

Fault Management The protocol designer should document the basic faults and health indicators that need to be instrumented for the new protocol, as well as the alarms and events that must be propagated to management applications or exposed through a data model. The protocol designer 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 the protocol designer 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? SNMP notifications and syslog messages can alert an operator when an aspect of the new protocol fails or encounters an error or failure condition, and SNMP is frequently used as a heartbeat monitor. Should the event reporting provide guaranteed accurate delivery of the event information within a given (high) margin of confidence? Can we poll the latest events in the box?

Liveness Detection and Monitoring Protocol designers should always build in basic testing features (e.g., ICMP echo, UDP/TCP echo service, NULL RPCs (remote procedure calls)) that can be used to test for liveness, with an option to enable and 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, such as Remote Monitoring (RMON) events/alarms or the EVENT-MIB, be usable to help determine error conditions? Are SNMP notifications for all events needed, or are there some "standard" notifications that could be used? Or can relevant counters be polled as needed?

Root Cause Analysis Root cause analysis is about working out where in the network the fault is. For example, if end-to-end data delivery is failing (reported by a notification), root cause analysis can help find the failed link or node in the end-to-end path.

Fault Isolation It might be useful to isolate or quarantine faults, such as isolating a device that emits malformed messages that are necessary to coordinate connections properly. This might be able to be done by configuring next-hop devices to drop the faulty messages to prevent them from entering the rest of the network.

Configuration Management A protocol designer should document the basic configuration parameters that need to be instrumented for a new protocol, 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 is not just multi-device push or pull. It is knowing that the configurations being pushed are semantically compatible. Is the circuit between them configured compatibly on both ends? Is the IS-IS metric the same? ... Now answer those questions for 1,000 devices. A number of 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. In some cases (such as access control lists (ACLs)), the order of data items is significant and comprises part of the configured data. If a protocol designer defines mechanisms for configuration, it would be desirable to standardize the order of elements for consistency of configuration and of reporting across vendors and across releases from vendors. There are two parts to this:

1. A Network Management System (NMS) could optimize ACLs for performance reasons.
2. Unless the device/NMS systems have correct rules / a lot of experience, reordering ACLs can lead to a huge security issue.

Network-wide configurations may be stored in central master databases and transformed into formats that can be pushed to devices, either by generating sequences of CLI commands or complete 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. Many operators consider it desirable 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 as a whole, rather than individual devices. Support for configuration transactions across a number of 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 Workshop was that textual configuration files should be able to contain international characters. Human-readable strings should utilize UTF-8, and protocol elements should be in case-insensitive ASCII. A mechanism to dump and restore configurations is a primitive operation needed by operators. Standards for pulling and pushing configurations from/to devices are desirable. 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.

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 could suggest techniques for testing the impact of the protocol on the network before it is deployed as well as techniques for testing the effect that the protocol has had on the network after being deployed. Protocol designers should consider how to test the correct end-to-end operation of the service or network, how to verify the correct functioning of the protocol, and whether that is verified by testing the service function and/or by testing the forwarding function of each network element. This may be achieved through status and statistical information gathered from devices.

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. 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. Search for "benchmark" in the RFC search tool. Performance metrics may be useful in multiple environments and for different protocols. The IETF, via the IP Performance Monitoring (IPPM) WG, has developed a set of standard metrics 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 monitoring, it is often important to report the time spent in a state, rather than reporting the current state. Snapshots are of less value for performance monitoring. There are several parts to performance management to be considered: protocol monitoring, device monitoring (the impact of the new protocol / service activation on the device), network monitoring, and service monitoring (the impact of service activation on the network).

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 the maximum value, or should they rollover? How can users determine if a rollover has occurred, and how can users determine if more than one rollover has occurred? 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 modelers of that protocol to determine how to handle it. For example, VLAN identifiers are defined by standard to range from 1 to 4094. Therefore, a YANG vlanid 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. Designers of an information model should model information, accessible at runtime, about the maximum number of protocol entity instances an implementation can support on a device, the current number of instances, and the expected behavior when the current instances exceed 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 looked at when measuring the operational performance of the network built using the protocol? Is it important to measure setup times? End-to-end connectivity? Hop-to-hop connectivity? Network throughput?

Monitoring the Service What are the principal performance factors that need to be looked at 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? User experience?

Security Management Protocol designers should consider how to monitor and manage security aspects and vulnerabilities of the new protocol. There will be security considerations related to the new protocol. To make it possible for operators to be aware of security-related events, it is recommended that system logs should record events, such as failed logins, but the logs must be secured. Should a system automatically notify operators of every event occurrence, or should an operator-defined threshold control when a notification is sent to an operator? Should certain statistics be collected about the operation of the new protocol that might be useful for detecting attacks, such as the receipt of malformed messages, messages out of order, or messages with invalid timestamps? If such statistics are collected, is it important to count them separately for each sender to help identify the source of attacks? Manageability considerations that are security-oriented might include discussion of the security implications when no monitoring is in place, the regulatory implications of absence of audit-trail or logs in enterprises, exceeding the capacity of logs, and security exposures present in chosen/recommended management mechanisms. 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 management interface, 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 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 access control lists are maintained and updated. Standard SNMP notifications or syslog messages might already exist, or can be defined, to alert operators to the conditions identified in the security considerations for the new protocol. For example, you can log all the commands entered by the operator using syslog (giving you some degree of audit trail), or you can see who has logged on/off using the Secure SHell Protocol (SSH) and from where; failed SSH logins can be logged using syslog, etc. An analysis of existing counters might help operators recognize the conditions identified in the security considerations for the new protocol before they can impact the network. 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.

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, 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. These events can be specifically leveraged to assess the operational (including manageability) implications of a new protocol 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.

Documentation Guidelines This document is focused on what a protocol designer should think about and how those considerations might be documented. This document does not describe interoperability requirements but rather describes practices that are useful to follow when dealing with manageability aspects in IETF documents, so the capitalized keywords from do not apply here. Any occurrence of words like 'must' or 'should' needs to be interpreted only in the context of their natural, English-language meaning.

Recommended Discussions A Manageability Considerations section should include discussion of the management and operations topics raised in this document, and when one or more of these topics is not relevant, it would be useful to contain a simple statement explaining why the topic is not relevant for the new protocol. Of course, additional relevant topics should be included as well. Existing protocols and data models can provide the management functions identified in the previous section. Protocol designers should consider how using existing protocols and data models might impact network operations.

Null Manageability Considerations Sections A protocol designer may seriously consider the manageability requirements of a new protocol and determine that no management functionality is needed by the new protocol. It would be helpful to those who may update or write extensions to the protocol in the future or to those deploying the new protocol to know the thinking of the working group regarding the manageability of the protocol at the time of its design. If there are no new manageability or deployment considerations, it is recommended that a Manageability Considerations section contain a simple statement such as, "There are no new manageability requirements introduced by this document," and a brief explanation of why that is the case. The presence of such a Manageability Considerations section would indicate to the reader that due consideration has been given to manageability and operations. In the case where the new protocol is an extension and the base protocol discusses all the relevant operational and manageability considerations, it would be helpful to point out the considerations section in the base document.

Placement of Operations and Manageability Considerations Sections If a protocol designer develops a Manageability Considerations section for a new protocol, it is recommended that the section be placed immediately before the Security Considerations section. Reviewers interested in such sections could find it easily, and this placement could simplify the development of tools to detect the presence of such a section.

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

Security Considerations This document is informational and provides guidelines for considering manageability and operations. It introduces no new security concerns. The provision of a management portal to a network device provides a doorway through which an attack on the device may be launched. Making the protocol under development be manageable through a management protocol creates a vulnerability to a new source of attacks. Only management protocols with adequate security apparatus, such as authentication, message integrity checking, and authorization, should be used. A standard description of the manageable knobs and whistles on a protocol makes it easier for an attacker to understand what they may try to control and how to tweak it. A well-designed protocol is usually more stable and secure. A protocol that can be managed and inspected offers the operator a better chance of spotting and quarantining any attacks. Conversely, making a protocol easy to inspect is a risk if the wrong person inspects it. If security events cause logs and/or notifications/alerts, a concerted attack might be able to be mounted by causing an excess of these events. In other words, the security-management mechanisms could constitute a security vulnerability. The management of security aspects is important (see ).

Informative References IETF IESG IAB 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). The purpose of this document is to provide an overview of the third version of the Internet-Standard Management Framework, termed the SNMP version 3 Framework (SNMPv3). This Framework is derived from and builds upon both the original Internet-Standard Management Framework (SNMPv1) and the second Internet-Standard Management Framework (SNMPv2). The architecture is designed to be modular to allow the evolution of the Framework over time. The document explains why using SNMPv3 instead of SNMPv1 or SNMPv2 is strongly recommended. The document also recommends that RFCs 1157, 1441, 1901, 1909 and 1910 be retired by moving them to Historic status. This document obsoletes RFC 2570. This memo provides information for the Internet community. It is the purpose of this document, the Structure of Management Information Version 2 (SMIv2), to define that adapted subset, and to assign a set of associated administrative values. [STANDARDS-TRACK] This RFC is intended to convey to the Internet community and other interested parties the recommendations of the Internet Activities Board (IAB) for the development of network management protocols for use in the TCP/IP environment. This memo does NOT, in and of itself, define or propose an Official Internet Protocol. It does reflect, however, the policy of the IAB with respect to further network management development in the short and long term. 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. 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. This document describes the use of the Common Open Policy Service (COPS) protocol for support of policy provisioning (COPS-PR). [STANDARDS-TRACK] 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. 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. 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. 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. North Carolina State University Old Dog Consulting 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 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 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 future IETF work. This document updates RFC 6291 by adding to the guidelines for the use of the term "OAM". It does not modify any other part of RFC 6291. 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] 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] 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). This document describes a protocol for carrying authentication, authorization, and configuration information between a Network Access Server which desires to authenticate its links and a shared Authentication Server. [STANDARDS-TRACK] The Diameter base protocol is intended to provide an Authentication, Authorization, and Accounting (AAA) framework for applications such as network access or IP mobility in both local and roaming situations. This document specifies the message format, transport, error reporting, accounting, and security services used by all Diameter applications. The Diameter base protocol as defined in this document obsoletes RFC 3588 and RFC 5719, and it must be supported by all new Diameter implementations. [STANDARDS-TRACK] 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. 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. 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] 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. 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] This memo describes a new IP Option type that alerts transit routers to more closely examine the contents of an IP packet. [STANDARDS-TRACK] 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] 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. 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] This document presents the object-oriented information model for representing policy information developed jointly in the IETF Policy Framework WG and as extensions to the Common Information Model (CIM) activity in the Distributed Management Task Force (DMTF). [STANDARDS-TRACK] This document proposes an informal management model of Differentiated Services (Diffserv) routers for use in their management and configuration. This model defines functional datapath elements (e.g., classifiers, meters, actions, marking, absolute dropping, counting, multiplexing), algorithmic droppers, queues and schedulers. It describes possible configuration parameters for these elements and how they might be interconnected to realize the range of traffic conditioning and per-hop behavior (PHB) functionalities described in the Diffserv Architecture. This memo provides information for the Internet community. This document specifies a number of changes to the Policy Core Information Model (PCIM, RFC 3060). Two types of changes are included. First, several completely new elements are introduced, for example, classes for header filtering, that extend PCIM into areas that it did not previously cover. Second, there are cases where elements of PCIM (for example, policy rule priorities) are deprecated, and replacement elements are defined (in this case, priorities tied to associations that refer to policy rules). Both types of changes are done in such a way that, to the extent possible, interoperability with implementations of the original PCIM model is preserved. This document updates RFC 3060. [STANDARDS-TRACK] This document presents an object-oriented information model of IP Security (IPsec) policy designed to facilitate agreement about the content and semantics of IPsec policy, and enable derivations of task- specific representations of IPsec policy such as storage schema, distribution representations, and policy specification languages used to configure IPsec-enabled endpoints. The information model described in this document models the configuration parameters defined by IPSec. The information model also covers the parameters found by the Internet Key Exchange protocol (IKE). Other key exchange protocols could easily be added to the information model by a simple extension. Further extensions can further be added easily due to the object-oriented nature of the model. This information model is based upon the core policy classes as defined in the Policy Core Information Model (PCIM) and in the Policy Core Information Model Extensions (PCIMe). [STANDARDS-TRACK] This document presents an object-oriented information model for representing Quality of Service (QoS) network management policies. This document is based on the IETF Policy Core Information Model and its extensions. It defines an information model for QoS enforcement for differentiated and integrated services using policy. It is important to note that this document defines an information model, which by definition is independent of any particular data storage mechanism and access protocol. The purpose of this document is to define an information model to describe the quality of service (QoS) mechanisms inherent in different network devices, including hosts. Broadly speaking, these mechanisms describe the properties common to selecting and conditioning traffic through the forwarding path (datapath) of a network device. This selection and conditioning of traffic in the datapath spans both major QoS architectures: Differentiated Services and Integrated Services. This document should be used with the QoS Policy Information Model (QPIM) to model how policies can be defined to manage and configure the QoS mechanisms (i.e., the classification, marking, metering, dropping, queuing, and scheduling functionality) of devices. Together, these two documents describe how to write QoS policy rules to configure and manage the QoS mechanisms present in the datapaths of devices. This document, as well as QPIM, are information models. That is, they represent information independent of a binding to a specific type of repository This document provides definitions of models and manageable objects for printing environments. The objects included in this MIB apply to physical, as well as logical entities within a printing device. This document obsoletes RFC 1759. [STANDARDS-TRACK] 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] YumaWorks Orange Huawei This memo provides guidelines for authors and reviewers of specifications containing YANG modules, including IANA-maintained 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. Also, this document updates RFC 8126 by providing additional guidelines for writing the IANA considerations for RFCs that specify IANA-maintained modules. 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. 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. 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. 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. 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. The Domain Name System (DNS) is defined in literally dozens of different RFCs. The terminology used by implementers and developers of DNS protocols, and by operators of DNS systems, has sometimes changed in the decades since the DNS was first defined. This document gives current definitions for many of the terms used in the DNS in a single document. This document obsoletes RFC 7719 and updates RFC 2308. 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. 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. 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. Note that this document is a report on the proceedings of the workshop. The views and positions documented in this report were expressed during the workshop by participants and do not necessarily reflect IAB's views and positions.

Acknowledgements TBC.

The author of RFC 5706:

David Harrington

Acknowledgments from RFC 5706:

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 this document, 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.