RFC 5706

Guidelines for Considering Operations and Management of New Protocols and Protocol Extensions

📅 published November 2009, from ietf

RFC 5706 🎀 Part 1 of 7: Guidelines for Considering Operations and Management of New Protocols and Protocol Extensions

Title block tea ☕

Author: D. Harrington, HuaweiSymantec USA 💅 Stream: Network Working Group ✨ Category: Informational 📚 Date: November 2009 🗓️ Obsoletes/Updates: this header doesn't list anything ✨

Abstract

okay so new protocols and protocol extensions are way better when people think about how they'll be run and managed from day one 🧚. Bolting on operations and management later is sub-optimal, lowkey painful, and honestly kinda architecturally unpleasant 💀. This doc gives guidance to the authors and reviewers of documents that define new protocols or protocol extensions, so they know which operations and management aspects they should consider 🫶.

Status of This Memo

This memo provides information for the Internet community. 🌸 It does not specify an Internet standard of any kind. 🙅‍♀️ Distribution of this memo is unlimited. 🦋

Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. 🔒

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. 📜 Please review these documents carefully, because they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the BSD License. 💖

This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. 🕰️ The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. 🌈

Table of Contents

   1. Introduction ....................................................4
      1.1. Designing for Operations and Management ....................4
      1.2. This Document ..............................................5
      1.3. Motivation .................................................5
      1.4. Background .................................................6
      1.5. Available Management Technologies ..........................7
      1.6. Terminology ................................................8
   2. Operational Considerations - How Will the New Protocol
      Fit into the Current Environment? ...............................8
      2.1. Operations .................................................9
      2.2. Installation and Initial Setup .............................9
      2.3. Migration Path ............................................10
      2.4. Requirements on Other Protocols and Functional
           Components ................................................11
      2.5. Impact on Network Operation ...............................11
      2.6. Verifying Correct Operation ...............................12
   3. Management Considerations - How Will the Protocol Be Managed? ..12
      3.1. Interoperability ..........................................14
      3.2. Management Information ....................................17
           3.2.1. Information Model Design ...........................18
      3.3. Fault Management ..........................................18
           3.3.1. Liveness Detection and Monitoring ..................19
           3.3.2. Fault Determination ................................19
           3.3.3. Root Cause Analysis ................................20
           3.3.4. Fault Isolation ....................................20
      3.4. Configuration Management ..................................20
           3.4.1. Verifying Correct Operation ........................22
      3.5. Accounting Management .....................................22
      3.6. Performance Management ....................................22
           3.6.1. Monitoring the Protocol ............................23
           3.6.2. Monitoring the Device ..............................24
           3.6.3. Monitoring the Network .............................24
           3.6.4. Monitoring the Service .............................25
      3.7. Security Management .......................................25
   4. Documentation Guidelines .......................................26
      4.1. Recommended Discussions ...................................27
      4.2. Null Manageability Considerations Sections ................27
      4.3. Placement of Operations and Manageability
           Considerations Sections ...................................28
   5. Security Considerations ........................................28
   6. Acknowledgements ...............................................28
   7. Informative References .........................................29
   Appendix A.  Operations and Management Review Checklist  ..........32
     A.1.  Operational Considerations ................................32
     A.2.  Management Considerations  ................................34
     A.3.  Documentation .............................................35

1. Introduction ✨

Often when new protocols or protocol extensions are developed, not enough thought goes into 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 can make deployment, operations, and management particularly hard. This document is here to help protocol designers and working groups think about operations and management functionality for their new IETF protocol or protocol extension at an earlier phase. 🎀

1.1. Designing for Operations and Management 🧚

The operational environment and manageability of the protocol should be considered from the start when new protocols are designed. 🌷

Most of the existing IETF management standards focus on using Structure of Management Information (SMI)-based data models (MIB modules) to monitor and manage networking devices. 🖥️ 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 emerging management requirements. 🔄 The discussion of emerging management requirements has a long history in the IETF, so it's giving veteran energy 👑. The set of management protocols you should use depends on what you are managing. 🫶

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 those threats should be mitigated, and then suggests appropriate standard protocols that could mitigate them. 🔐

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. 🍓

1.2. This Document 🦋

This document makes a distinction between "Operational Considerations" and "Management Considerations", although the two are closely related. 💅 The section on manageability focuses 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 no management protocol is 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 those 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 is a decision that can be made case by 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, because it states that this is how the protocol will need to be operated and managed. 📣 Protocol designers should avoid having manageability pushed to a later phase of the development of the standard. 🙈

In discussing the importance of considering operations and management, this document sets forth a list of guidelines and a checklist of questions to consider (see Appendix A). ⭐ A protocol designer or reviewer can use these to evaluate whether the protocol and its documentation address common operations and management needs. 🔥 Operations and management are highly dependent on their environment, so most guidelines are subjective rather than objective. 💖

1.3. Motivation ✨

okay so for years the IETF crew has been using the IETF Standard Management Framework 💅 That includes the Simple Network Management Protocol [RFC3410], the Structure of Management Information [RFC2578], and MIB data models for managing new protocols. But as the Internet has glowed up 🌈, operators noticed that relying on one protocol and one schema language for managing everything is giving not enough. The IESG policy that made working groups write a MIB module to get manageability for new protocols is being replaced with something more open, one that welcomes a variety of management protocols and data models built for different goals 🦋

This document gives some first-draft guidelines for thinking about operations and management inside an IETF Management Framework made of multiple protocols and multiple data-modeling languages 🧚 The vibe is flexible, but we're still striving for interoperability, bestie 🫶

Brand-new protocols may need a lot of thought about how they'll be operated and managed, while extensions to existing, widely deployed protocols may already have established de facto operations and management practices that everyone understands 🍓

Suitable management approaches can differ between areas, working groups, and protocols in the IETF. This document does not prescribe a fixed solution or format for operational and management aspects of IETF protocols. However, these aspects should be considered for any IETF protocol, because we build technologies and protocols to be deployed and operated on the real-world Internet 🌸 It's fine if a WG decides its protocol doesn't need interoperable management or a standardized data model, but that should be a deliberate decision, not the result of omission 💜 This document provides some guidelines for those considerations ✨

1.4. Background 📚

There have been a lot of efforts, meetings, and documents related to Internet operations and management 👑 Some are mentioned here so protocol designers can find documentation of earlier work. Hopefully these references 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" [RFC1052]. It recommended a solution that, where possible, deliberately separates modeling languages, data models, and the protocols that carry data 💖 The goal is to let standardized information and data models 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" [RFC3139] 🎀

In 2003, the Internet Architecture Board (IAB) held a workshop on Network Management [RFC3535]. It discussed the strengths and weaknesses of some IETF network management protocols and compared them to operational needs, especially configuration 🔥

One issue discussed was how user-unfriendly the binary format of SNMP [RFC3410] and Common Open Policy Service (COPS) Usage for Policy Provisioning (COPS-PR) [RFC3084] is 😭 The workshop 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, root cause analysis, and logging are not sufficient, and that there's a need to support both 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 for a document discussing how protocol designers and working groups should handle management in this emerging multi-protocol environment. This document and some planned companion documents try to offer guidelines for navigating the rapidly shifting operating and management environments 🦋

1.5. Available Management Technologies 🛠️

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

  • Simple Network Management Protocol - SNMP [RFC3410]
  • Syslog [RFC5424]
  • Remote Authentication Dial-In User Service - RADIUS [RFC2865]
  • DIAMETER [RFC3588]
  • Network Configuration Protocol - NETCONF [RFC4741]
  • IP Flow Information Export - IPFIX [RFC5101]

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

1.6. Terminology 🎀

This document deliberately does not use the (capitalized) keywords described in RFC 2119 [RFC2119]. RFC 2119 says the keywords must only be used where they're actually required for interoperation or to limit behavior that 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 that method isn't required for interoperability. This informational document is a set of guidelines based on current practices of some protocol designers and operators. It 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 [RFC3444].
  • 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 [RFC3444].
  • 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.

2. Operational Considerations - How Will the New Protocol Fit into the Current Environment? 🌈

Designers of a new protocol should carefully consider the operational aspects 🧠 To make sure a protocol is practical to deploy in the real world, it isn't enough to define it very precisely in a well-written document. Operational aspects have a serious impact on whether a protocol actually succeeds 😭 Those aspects include bad interactions with existing solutions, a difficult upgrade path, difficulty debugging problems, difficulty configuring from a central database, or a complicated state diagram that operations staff will struggle to understand.

BGP flap damping [RFC2439] is a perfect example 💀 It was designed to block high-frequency route flaps. However, the design didn't account for BGP path exploration / slow convergence. In real operations, path exploration caused false flap damping, which resulted in loss of reachability. As a result, many networks turned flap damping off 🙈

2.1. Operations 🛠️

Protocol designers can analyze the operational environment and mode of work in which the new protocol or extension will run. That exercise doesn't need to show up directly in their document, but it can help them visualize 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 choose 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, so that the information exposed by both is consistent when an operator sees it 🧚 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 deploying the protocol 🍓 For example: whether write operations will be allowed on routers and on hosts, or whether notifications for alarms or other events will be expected.

2.2. Installation and Initial Setup 🎀

Anything that can be configured can be misconfigured 😭 "Architectural Principles of the Internet" [RFC1958], 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, the default state of logical control variables, default transports, and so on. Even when 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 let operators concentrate on configuring the network as a whole rather than on individual devices. Of course, how one accomplishes this is the hard part 🫶

It's desirable to discuss the background of chosen default values, or 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's 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 shouldn't 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 the "optimizing performance" side (example: the initial RTT and RTTvar values of a TCP connection) 🌸

For parameters that are speed-dependent, instead of using a constant, try setting 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 🌈

2.3. Migration Path 🦋

okay so, if the new protocol is a new version of an existing one, or it's replacing some other technology, the protocol designer should totally think about how deployments transition over to it 💅 that includes coexistence with previously deployed protocols and/or previous versions of the same protocol, incompatibilities between versions, translation between versions, and side effects that might happen. are older protocols or versions switched off, or do they coexist in the network with the new protocol? the vibe check is real 👀

many protocols are giving incrementally deployable energy 🌸 operators can roll out pieces of a protocol before they deploy the whole thing. so smart!

2.4. Requirements on Other Protocols and Functional Components 🧚

protocol designers should think about what requirements the new protocol might put on other protocols and functional components 💜 they should also write down the requirements from other protocols and functional elements that were considered while designing the new protocol. no hidden drama!

these considerations should generally stay illustrative so they don't create restrictions or dependencies, don't accidentally mess with how existing protocols behave, don't limit the extensibility of other protocols, and don't assume other protocols will never be extended in certain ways. if restrictions or dependencies do exist, they should be stated 🫶

for example, the design of the Resource ReSerVation Protocol (RSVP) [RFC2205] 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 early designers overlooked that a new "deep packet inspection" requirement was being put on the functional components of a router. the "router alert" option ([RFC2113], [RFC2711]) 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. the plot twist nobody wanted 💀

2.5. 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 light of the impact on the scalability of the interior gateway protocols operating within the network. big numbers, big consequences 📈

a protocol could send active monitoring packets on the wire. if we don't pay attention, we might get very good accuracy, but we could also send too many active monitoring packets. accuracy is iconic, but spam is not 🙈

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 get added to the network as a result of configuration changes, such as servers performing auto-configuration operations. the network is a whole ecosystem, bestie 🌿

the protocol designer should also consider the impact on infrastructure applications like DNS [RFC1034], the registries, or the size of routing tables. for example, Simple Mail Transfer Protocol (SMTP) [RFC5321] 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. 😭 one filter, whole mail server down. iykyk, and now we all know 🙃

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. A to B with the least drama possible 🎀

2.6. 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? ask the real questions, bestie 🧐

having simple protocol status and health indicators on network devices is a recommended means to check correct operation. simple dashboards, big energy 💖

3. 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. step one: know your people 💅

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 that are 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 [RFC3535] 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 at 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. scale-appropriate management is a whole mood 🌟

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. the device doesn't always know the big picture, periodt 🙈

WGs should consider how to configure multiple related or co-operating devices, and how to back off if one of those configurations fails or causes trouble. NETCONF [RFC4741] addresses this in a generic manner by allowing an operator to lock the configuration on multiple devices, perform the configuration settings or changes, check that they are OK (undo if not), and then unlock the devices. lock, change, check, undo if needed, unlock. such a clean routine 🫶

techniques for debugging protocol interactions in a network must be part of the network-management discussion. implementation source code should be debugged before it is ever 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. debug the code first, debug the wire second, and never mix up the state machine with the wire 🧠

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. one server, many friends affected, so watch the server first 👑

3.1. Interoperability ✨

okay so bestie, management interoperability is something we need to think about every time we deploy protocols that connect devices 💅 That means across devices from different vendors, across models from the same vendor, or across different releases of the same product. It's giving "everyone can talk to everyone," and that's the whole point. Management interoperability is about letting devices and multiple management applications (often from different vendors) share info and run operations together. It also means you can use third-party apps and outsource management services, which is so iconic 🫶

Some product and protocol designers think that if a device can be managed one at a time through a command line interface or a web page, that's enough. Literally not enough 💀 Once equipment from multiple vendors gets combined into a big network, managing it at scale can become a real problem. Consistency across management interfaces matters, because it's what lets network-wide processes get automated. Like, a single switch is totally fine to manage through an interactive web page when it's sitting in one small office. But imagine a fast-food company that installs similar switches from several vendors in hundreds or thousands of branches and wants to monitor them all from one central spot. Checking vendor- and model-specific web pages one by one would be a nightmare to automate 😭

The main goal is being able to roll out new useful functions and services in a way that can be managed at scale. You also need to understand the network impact of that service, which counts as part of the total cost of operations 🧚

Getting everybody to agree on one syntax and one protocol to do all management has been really hard, not gonna lie. So management systems end up speaking whatever the boxes support, whether or not the IETF approves 🙈 The IETF is moving away from relying on one schema language for modeling management information (Structure of Management Information Version 2 (SMIv2) [RFC2578]) and one simple network management protocol (Simple Network Management Protocol (SNMP) [RFC3410]). Instead, it's supporting more schema languages and more management protocols, each 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 in some cases those may fit better than IETF ones 💖 Some of the alternatives being considered include:

  • XML Schema Definition [W3C.REC-xmlschema-0-20010502]

and

  • NETCONF Configuration Protocol [RFC4741]
  • the IP Flow Information Export (IPFIX) Protocol [RFC5101]) for usage accounting
  • the syslog protocol [RFC5424] for logging

Interoperability has to be thought about on both the syntactic level and the semantic level 🎀 Syntactic differences can be annoying and time-consuming to deal with, but application designers (including operators who write their own scripts) can make their processing conditional so it accommodates differences across vendors, models, or releases of a product.

Semantic differences are way harder to handle on the manager side 😩 Once you have the data, what it means depends on the managed entity.

Information models help keep interoperability focused on the semantic level 🦋 They set standards for what information should be gathered and how it might be used, no matter which management interface carries the data or which vendor made the product. An information model might also help operators correlate messages across different protocols when the data overlaps, like a syslog message and an SNMP notification about the same event. It can also decide which error conditions should be counted separately and which ones can be counted together in a single counter. Then, whether that counter gets gathered through SNMP, a CLI command, or a syslog message, it means the same thing every time ✨

Protocol designers should think about which information could be useful for managing the new protocol or its extensions 🌸

                IM                --> conceptual/abstract model
                 |                    for designers and operators
      +----------+---------+
      |          |         |
      DM        DM         DM     --> concrete/detailed model
                                      for implementers

Information Models and Data Models

Figure 1

Protocol designers may decide that an information model or a data model would be a good fit for managing the new protocol or its extensions 💜

"On the Difference between Information Models and Data Models" [RFC3444] can help you figure out what info to consider for information models (IMs) versus data models (DMs) 🍓

Information models should come from the protocol WGs and list the events, counters, and configuration parameters that matter. There are already a bunch of information models in protocol WG RFCs. Some examples:

  • [RFC3060] - Policy Core Information Model version 1
  • [RFC3290] - An Informal Management Model for Diffserv Routers
  • [RFC3460] - Policy Core Information Model Extensions
  • [RFC3585] - IPsec Configuration Policy Information Model
  • [RFC3644] - Policy Quality of Service Information Model
  • [RFC3670] - Information Model for Describing Network Device QoS Datapath Mechanisms
  • [RFC3805] - Printer MIB v2 (contains both an IM and a DM)

Management protocol standards and management data model standards often include compliance clauses to make sure things interoperate. Manageability considerations should discuss which level of compliance is expected to be supported for interoperability 🫶

3.2. Management Information

Languages used to describe an information model can shape what the model looks like 👑 For example, using a data-modeling language like SMIv2 pushes the model toward certain structures, such as two-dimensional tables. This document recommends describing an information model in English text (the official language for IETF specifications) 🇬🇧 A sample data model can be developed to demonstrate the information model ✨

A management information model should talk about 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 which events should notify an operator 🔥

Operators really need to be able to clearly tell apart configuration data, operational state, and statistics 💅 They need to figure out which parameters were administratively configured and which ones have changed since configuration because of things like routing protocols or network management protocols. It's important to be able to separately fetch current configuration, initial configuration, operational state, and statistics from devices. You also need to be able to compare current state to initial state, and compare info between devices. So when you decide what information should exist, don't mash multiple information elements into a single element 🙅‍♀️

What's usually the hardest part is working out relationships between abstract objects 🧩 Ideally, an information model would describe the relationships between the objects and concepts in it.

Is there always just one instance of this object, or can there be multiple? Does this object relate to exactly one other object, or to several? When is it possible to change a relationship? Do objects (such as rows in tables) share fate? For example, if a row in table A must exist before a related row in table B can be created, what happens to the row in table B if the related row in table A is deleted? Does the existence of relationships between objects affect fate sharing? 🤔

3.2.1. 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.

3.3. Fault Management

The protocol designer should document the basic faults and health indicators that need to be instrumented for the new protocol 🚨 They should also document 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 by polling health indicators? 🤷‍♀️

If notifications are used to alert operators to certain conditions, then the protocol designer should discuss mechanisms to throttle notifications, so they don't cause congestion or duplicate event notifications 🚦 Will there be a hierarchy of faults? If so, will each fault in the hierarchy be reported, or will only the lowest fault be reported with the higher levels suppressed? Should there be aggregated status indicators based on concatenating propagated faults from a given domain or device? SNMP notifications and syslog messages can alert an operator when some part of the new protocol fails or runs into an error or failure condition, and SNMP is frequently used as a heartbeat monitor 💓 Should event reporting guarantee accurate delivery of event information within a given (high) margin of confidence? Can we poll the latest events in the box? 👀

3.3.1. 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 in other protocols that maintain lower-layer connectivity (e.g., ICMP echo). But often new procedures are required to detect failures and to report them rapidly, so remedial action can be taken 🏃‍♀️

These liveness monitoring mechanisms don't 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 📝

3.3.2. Fault Determination 🔍

okay so this bit is about figuring out where things went wrong using management info 🕵️‍♀️ For example, counters can log every time an error pops up. Some faults can be pinpointed by comparing what one device sends out with what another device receives, and looking for anomalies (aka the "wait, that doesn't match" moments 😭). Protocol designers should think really carefully about what counters should count 🧮 Like, if vendor A's counter lumps together three kinds of error conditions, but vendor B's matching counter tracks seven, those counters can't be compared properly. They're not interoperable counters, and that's a whole mess 💀

How do you tell faulty messages apart from good messages? 🤔

Would threshold-based mechanisms help figure out error conditions? Think Remote Monitoring (RMON) events/alarms or the EVENT-MIB 🚨 Are SNMP notifications needed for all events, or are there some "standard" notifications that could be used instead? Or can the relevant counters just be polled whenever you need them? 💅

3.3.3. Root Cause Analysis 🧠

Root cause analysis is all about figuring out where in the network the fault actually is 📍 For example, if end-to-end data delivery is failing (and a notification is telling you so), root cause analysis can help you find the failed link or node somewhere along the end-to-end path. Detective era, bestie 🕵️‍♀️✨

3.3.4. Fault Isolation 🧯

Sometimes it's useful to isolate or quarantine faults 🔒 Like, say a device is emitting malformed messages that are needed to coordinate connections properly. One way to handle that is configuring next-hop devices to drop the faulty messages, so they can't spread into the rest of the network. Containment is everything 🫶

3.4. Configuration Management ⚙️

A protocol designer should document the basic configuration parameters that need to be instrumented for a new protocol, along with default values and modes of operation 📝

What information should be kept across reboots of the device, or restarts of the management system? 🔄

"Requirements for Configuration Management of IP-based Networks" [RFC3139] talks about requirements for configuration management, including different levels of management, high-level policies, network-wide configuration data, and device-local configuration 🗂️ Network configuration is not just pushing or pulling stuff from multiple devices. It's knowing that the configurations being pushed are semantically compatible. Is the circuit between two devices configured compatibly on both ends? Is the IS-IS metric the same? ... Now answer those questions for 1,000 devices 😵‍💫💀

A bunch of efforts in the IETF have tried to develop policy-based configuration management 🎀 "Terminology for Policy-Based Management" [RFC3198] was written to standardize the terminology across those efforts, so everyone's speaking the same language 🗣️

Implementations should not arbitrarily modify configuration data 🙅‍♀️ In some cases (like access control lists (ACLs)), the order of data items is significant and is actually part of the configured data. So if a protocol designer defines mechanisms for configuration, it would be desirable to standardize the order of elements, so configuration and reporting stay consistent across vendors and across releases from vendors 📋

There are two parts to this, and both are spicy 🌶️

  1. A Network Management System (NMS) could optimize ACLs for performance reasons.
  2. Unless the device/NMS systems has 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 🗄️ That can happen by generating sequences of CLI commands, or by generating complete configuration files that get pushed to devices. There is no common database schema for network configuration, even though the models used by various operators are probably very similar 👀 Lots of operators would love 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 also recognizing that vendors may have proprietary aspects of their configurations 💅

It's important to let operators focus on the configuration of the network as a whole, rather than individual devices 🌐 Support for configuration transactions across a number of devices could seriously simplify network configuration management ✨ Being able to distribute configurations to multiple devices, or modify candidate configurations on multiple devices and then activate them in a near-simultaneous manner, might help a lot. Protocol designers can consider how it would make sense for their protocol to be configured across multiple devices. Configuration templates might also be helpful 🧩

The consensus of the 2002 IAB Workshop [RFC3535] was that textual configuration files should be able to contain international characters 🌍 Human-readable strings should use UTF-8, and protocol elements should be in case-insensitive ASCII 🔤

A mechanism to dump and restore configurations is a primitive operation that operators need 💾 Standards for pulling and pushing configurations from and to devices are desirable 🫶

Given configuration A and configuration B, it should be possible to generate the operations needed to get from A to B with minimal state changes and minimal effects on the network and systems 🦋 It's important to minimize the impact caused by configuration changes, bestie 🙏

A protocol designer should consider the configurable items that exist for controlling function via the protocol elements described in the protocol specification 🎛️ For example, sometimes the protocol requires that timers can be configured by the operator, so the implementation shows specific policy-based behavior. These timers should have default values suggested in the protocol specification, and may not need to be otherwise configurable ⏱️

3.4.1. 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's deployed, as well as techniques for testing the effect the protocol has had on the network after it's 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's verified by testing the service function, testing the forwarding function of each network element, or both 🧪 This may be achieved through status and statistical information gathered from devices 📊

3.5. 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" [RFC2975] 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 📈

3.6. Performance Management 🏎️

From a manageability point of view, it's important to determine how well a network deploying the protocol or technology defined in the document is doing 📶 To do this, network operators need to consider information that would be useful for determining the performance characteristics of a deployed system using the target protocol 🔎

The IETF, via the Benchmarking Methodology WG (BMWG), has defined recommendations for measuring the performance characteristics of various internetworking technologies in a laboratory environment, including the systems or services built from those technologies 🧪 Each benchmarking recommendation describes the class of equipment, system, or service being addressed. It discusses the performance characteristics that are pertinent to that class, clearly identifies a set of metrics that help describe those characteristics, specifies the methodologies required to collect those metrics, and lastly presents the requirements for 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 so 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, and it would be useful if the protocol documentation identified the need for those new metrics 📏 For performance monitoring, it's 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 consider: protocol monitoring, device monitoring (the impact of the new protocol or service activation on the device), network monitoring, and service monitoring (the impact of service activation on the network) 🧩

3.6.1. 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 🎯

Think about the expected behaviors for counters. What's a reasonable maximum value for expected usage? Should they stop counting at the maximum value and keep that maximum value, or should they roll over? How can users determine whether a rollover has occurred, and how can they determine whether 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 the other applications 🙅‍♀️

Could events, like hot-swapping a blade in a chassis, cause discontinuities in a counter? Does this make any difference when evaluating the performance of a protocol? 🤷‍♀️

The protocol document should make clear the limitations implicit within the protocol, and the behavior when limits are exceeded. This should be considered in a data-modeling-independent manner: what makes managed-protocol sense, not what makes management-protocol-sense. If constraints are not managed-protocol-dependent, then it should be left for the management-protocol data modelers to decide. For example, VLAN identifiers have a range of 1..4095 because of the VLAN standards. A MIB implementing a VLAN table should be able to support 4096 entries because the content being modeled requires it 🧠✨

3.6.2. Monitoring the Device 💻

okay so, you have to think about whether the device's performance is gonna take a hit based on how many protocol entities are running on it 👀 information model designers should include runtime-accessible info about the max number of instances an implementation can support, the current number of instances, and what the expected behavior is when the current instances go over the capacity of the implementation or the capacity of the device 🫶

designers of an information model should model runtime-accessible info about the max number of protocol entity instances an implementation can support on a device, the current count, and the expected behavior when the current instances exceed the capacity of the device ✨

3.6.3. Monitoring the Network 🌐

consider whether network performance will be affected by how many protocol entities get deployed 🕸️

consider being able to figure out the operational activity, like the number of messages coming in and going out, the number of received messages rejected because of format problems, and the expected behaviors when a malformed message shows up 👀

so what are the principal performance factors you need to look at when measuring the operational performance of a network built using the protocol? is it important to measure setup times? end-to-end connectivity? hop-to-hop connectivity? network throughput? 🤔

3.6.4. Monitoring the Service 🎀

what are the principal performance factors you need to look 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? 💅

3.7. Security Management 🔐

protocol designers should consider how to monitor and manage the security aspects and vulnerabilities of the new protocol 🕵️‍♀️

there will be security considerations related to the new protocol 😬 so to help operators stay aware of security-related events, it is recommended that system logs record events like failed logins, but the logs must be secured 🔒

should a system automatically notify operators of every single event occurrence, or should an operator-defined threshold control when a notification gets sent to an operator? 🔔

should certain statistics be collected about how the new protocol operates that could be useful for detecting attacks, like the receipt of malformed messages, messages out of order, or messages with invalid timestamps? and if those statistics get collected, is it important to count them separately for each sender so you can figure out where attacks are coming from? 🧐

manageability considerations that are security-oriented might include discussion of the security implications when no monitoring is in place, the regulatory implications of not having an audit trail or logs in enterprises, exceeding the capacity of logs, and security exposures present in chosen or recommended management mechanisms 📋

consider security threats that management operations might introduce 💀 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 info that used to be inaccessible is now exposed over the network and to management applications, and that can 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 only be given the minimum access needed to perform a required task 👑

some operators want to do consistency checks of access control lists across devices. protocol designers should consider information models that make comparisons across devices and across vendors possible, so you can check that the security configurations are consistent 🧩

protocol designers should consider how to provide a secure transport, authentication, identity, and access control that plays nicely with existing key and credential management infrastructure. it is a good idea to start by defining the threat model for the protocol, and then work out from that what is required 🧠

protocol designers should consider how access control lists are maintained and updated 🗂️

standard SNMP notifications or syslog messages [RFC5424] 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 an operator enters using syslog (which gives you some degree of audit trail), or you can see who has logged on and off using the Secure SHell Protocol (SSH) and from where, and 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 make different assumptions about message security and data-access controls 😤 a protocol designer who recommends using different protocols should consider how security will be applied in a balanced way 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, data-oriented or task-oriented approaches sometimes make more sense. protocol designers should consider both data-oriented and task-oriented authority levels and policy 💜

4. 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 [RFC2119] 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 🙈

a Manageability Considerations section should include discussion of the management and operations topics raised in this document. when one or more of these topics is not relevant, it would be useful to include 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 🧚

4.2. 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 section would tell 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 🔗

4.3. 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 🔍

5. 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 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 gives 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 themselves constitute a security vulnerability. the management of security aspects is important (see Section 3.7). 🔥

6. Acknowledgements 🫶

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, Juergen Schoenwaelder, Andy Bierman, and David Harrington 🧚‍♀️

thanks to the reviewers who helped fashion this document, including Harald Alvestrand, Ron Bonica, Brian Carpenter, Benoit Claise, Adrian Farrel, David Kessens, Dan Romascanu, Pekka Savola, Juergen Schoenwaelder, Bert Wijnen, Ralf Wolter, and Lixia Zhang. you're all iconic 👑💜

7. Informative References ✨

Okay bestie, this is the reading list 📚 every reference the spec leans on, all lined up with their details. Don't skip these, they're the receipts 🧾

[RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
           STD 13, RFC 1034, November 1987.

[RFC1052]  Cerf, V., "IAB recommendations for the development of
           Internet network management standards", RFC 1052,
           April 1988.

[RFC1958]  Carpenter, B., "Architectural Principles of the Internet",
           RFC 1958, June 1996.

[RFC2113]  Katz, D., "IP Router Alert Option", RFC 2113,
           February 1997.

[RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
           Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2205]  Braden, B., Zhang, L., Berson, S., Herzog, S., and S.
           Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
           Functional Specification", RFC 2205, September 1997.

[RFC2439]  Villamizar, C., Chandra, R., and R. Govindan, "BGP Route
           Flap Damping", RFC 2439, November 1998.

[RFC2578]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
           Schoenwaelder, Ed., "Structure of Management Information
           Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.

[RFC2711]  Partridge, C. and A. Jackson, "IPv6 Router Alert Option",
           RFC 2711, October 1999.

[RFC2865]  Rigney, C., Willens, S., Rubens, A., and W. Simpson,
           "Remote Authentication Dial In User Service (RADIUS)",
           RFC 2865, June 2000.

[RFC2975]  Aboba, B., Arkko, J., and D. Harrington, "Introduction to
           Accounting Management", RFC 2975, October 2000.

[RFC3060]  Moore, B., Ellesson, E., Strassner, J., and A. Westerinen,
           "Policy Core Information Model -- Version 1
           Specification", RFC 3060, February 2001.

[RFC3084]  Chan, K., Seligson, J., Durham, D., Gai, S., McCloghrie,
           K., Herzog, S., Reichmeyer, F., Yavatkar, R., and A.
           Smith, "COPS Usage for Policy Provisioning (COPS-PR)",
           RFC 3084, March 2001.

[RFC3139]  Sanchez, L., McCloghrie, K., and J. Saperia, "Requirements
           for Configuration Management of IP-based Networks",
           RFC 3139, June 2001.

[RFC3198]  Westerinen, A., Schnizlein, J., Strassner, J., Scherling,
           M., Quinn, B., Herzog, S., Huynh, A., Carlson, M., Perry,
           J., and S. Waldbusser, "Terminology for Policy-Based
           Management", RFC 3198, November 2001.

[RFC3290]  Bernet, Y., Blake, S., Grossman, D., and A. Smith, "An
           Informal Management Model for Diffserv Routers", RFC 3290,
           May 2002.

[RFC3410]  Case, J., Mundy, R., Partain, D., and B. Stewart,
           "Introduction and Applicability Statements for Internet-
           Standard Management Framework", RFC 3410, December 2002.

[RFC3444]  Pras, A. and J. Schoenwaelder, "On the Difference between
           Information Models and Data Models", RFC 3444,
           January 2003.

[RFC3460]  Moore, B., "Policy Core Information Model (PCIM)
           Extensions", RFC 3460, January 2003.

[RFC3535]  Schoenwaelder, J., "Overview of the 2002 IAB Network
           Management Workshop", RFC 3535, May 2003.

[RFC3585]  Jason, J., Rafalow, L., and E. Vyncke, "IPsec
           Configuration Policy Information Model", RFC 3585,
           August 2003.

[RFC3588]  Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
           Arkko, "Diameter Base Protocol", RFC 3588, September 2003.

[RFC3644]  Snir, Y., Ramberg, Y., Strassner, J., Cohen, R., and B.
           Moore, "Policy Quality of Service (QoS) Information
           Model", RFC 3644, November 2003.

[RFC3670]  Moore, B., Durham, D., Strassner, J., Westerinen, A., and
           W. Weiss, "Information Model for Describing Network Device
           QoS Datapath Mechanisms", RFC 3670, January 2004.

[RFC3805]  Bergman, R., Lewis, H., and I. McDonald, "Printer MIB v2",
           RFC 3805, June 2004.

[RFC4741]  Enns, R., "NETCONF Configuration Protocol", RFC 4741,
           December 2006.

[RFC5101]  Claise, B., "Specification of the IP Flow Information
           Export (IPFIX) Protocol for the Exchange of IP Traffic
           Flow Information", RFC 5101, January 2008.

[RFC5321]  Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
           October 2008.

[RFC5424]  Gerhards, R., "The Syslog Protocol", RFC 5424, March 2009.

[W3C.REC-xmlschema-0-20010502]
           Fallside, D., "XML Schema Part 0: Primer", World Wide Web
           Consortium FirstEdition REC-xmlschema-0-20010502,
           May 2001,
           <http://www.w3.org/TR/2001/REC-xmlschema-0-20010502>.

Appendix A. Operations and Management Review Checklist 🧐

Okay so this appendix is basically a cheat sheet 📝 of the questions that operations and management reviewers are going to side-eye your spec for when it's up for consideration as a protocol standard. Think of it as getting ready for the pre-game ✨ so nothing catches you off guard.

A.1. Operational Considerations 🛠️

  1. Has deployment been discussed? See Section 2.1.
    • Does the document include a description of how this protocol or technology is going to be deployed and managed?
    • Is the proposed specification deployable? If not, how could it be improved?
    • Does the solution scale well from the operational and management perspective? Does the proposed approach have any scaling issues that could affect usability for large-scale operation?
    • Are there any coexistence issues?
  2. Has installation and initial setup been discussed? See Section 2.2.
    • Is the solution sufficiently configurable?
    • Are configuration parameters clearly identified?
    • Are configuration parameters normalized?
    • Does each configuration parameter have a reasonable default value?
    • Will configuration be pushed to a device by a configuration manager, or pulled by a device from a configuration server?
    • How will the devices and managers find and authenticate each other?
  3. Has the migration path been discussed? See Section 2.3.
    • Are there any backward compatibility issues?
  4. Have the Requirements on other protocols and functional components been discussed? See Section 2.4.
    • What protocol operations are expected to be performed relative to the new protocol or technology, and what protocols and data models are expected to be in place or recommended to ensure for interoperable management?
  5. Has the impact on network operation been discussed? See Section 2.5.
    • Will the new protocol significantly increase traffic load on existing networks?
    • Will the proposed management for the new protocol significantly increase traffic load on existing networks?
    • How will the new protocol impact the behavior of other protocols in the network? Will it impact performance (e.g., jitter) of certain types of applications running in the same network?
    • Does the new protocol need supporting services (e.g., DNS or Authentication, Authorization, and Accounting - AAA) added to an existing network?
  6. Have suggestions for verifying correct operation been discussed? See Section 2.6.
    • How can one test end-to-end connectivity and throughput?
    • Which metrics are of interest?
    • Will testing have an impact on the protocol or the network?
  7. Has management interoperability been discussed? See Section 3.1.
    • Is a standard protocol needed for interoperable management?
    • Is a standard information or data model needed to make properties comparable across devices from different vendors?
  8. Are there fault or threshold conditions that should be reported? See Section 3.3.
    • Does specific management information have time utility?
    • Should the information be reported by notifications? Polling? Event-driven polling?
    • Is notification throttling discussed?
    • Is there support for saving state that could be used for root cause analysis?
  9. Is configuration discussed? See Section 3.4.
    • Are configuration defaults and default modes of operation considered?
    • Is there discussion of what information should be preserved across reboots of the device or the management system? Can devices realistically preserve this information through hard reboots where physical configuration might change (e.g., cards might be swapped while a chassis is powered down)?

A.2. Management Considerations 📊

Do you anticipate any manageability issues with the specification?

  1. Is management interoperability discussed? See Section 3.1.
    • Will it use centralized or distributed management?
    • Will it require remote and/or local management applications?
    • Are textual or graphical user interfaces required?
    • Is textual or binary format for management information preferred?
  2. Is management information discussed? See Section 3.2.
    • What is the minimal set of management (configuration, faults, performance monitoring) objects that need to be instrumented in order to manage the new protocol?
  3. Is fault management discussed? See Section 3.3.
    • Is Liveness Detection and Monitoring discussed?
    • Does the solution have failure modes that are difficult to diagnose or correct? Are faults and alarms reported and logged?
  4. Is configuration management discussed? See Section 3.4.
    • Is protocol state information exposed to the user? How? Are significant state transitions logged?
  5. Is accounting management discussed? See Section 3.5.
  6. Is performance management discussed? See Section 3.6.
    • Does the protocol have an impact on network traffic and network devices? Can performance be measured?
    • Is protocol performance information exposed to the user?
  7. Is security management discussed? See Section 3.7.
    • Does the specification discuss how to manage aspects of security, such as access controls, managing key distribution, etc.

A.3. Documentation 📝

Is an operational considerations and/or manageability section part of the document?

Does the proposed protocol have a significant operational impact on the Internet?

Is there proof of implementation and/or operational experience?

Author's Address 💌

David Harrington HuaweiSymantec USA 20245 Stevens Creek Blvd Cupertino, CA 95014 USA

Phone: +1 603 436 8634 EMail: ietfdbh@comcast.net

📦 where this page comes from