One document matched: draft-ietf-opsawg-operations-and-management-07.xml
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<front>
<title abbrev="Ops and Mgmt Guidelines">Guidelines for Considering
Operations and Management of New Protocols and Protocol Extensions</title>
<author fullname="David Harrington" initials="D" surname="Harrington">
<organization>Huawei Technologies USA</organization>
<address>
<postal>
<street>1700 Alma Dr, Suite 100</street>
<city>Plano</city>
<region>TX</region>
<code>75075</code>
<country>USA</country>
</postal>
<phone>+1 603 436 8634</phone>
<facsimile></facsimile>
<email>dharrington@huawei.com</email>
<uri></uri>
</address>
</author>
<date year="2009" />
<area>IETF Operations and Management Area</area>
<keyword>management</keyword>
<keyword>operations</keyword>
<abstract>
<t>New protocols or protocol extensions are best designed with due
consideration of 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 defining new protocols or protocol extensions, about covering
aspects of operations and management that should be considered.</t>
</abstract>
</front>
<middle>
<section title="Introduction">
<t>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. Since the ease of operations and management may
impact the success of IETF protocols, this document provides guidelines
to help protocol designers and working groups consider the operations
and management functionality needed by their new IETF protocol or
protocol extension at an earlier phase.</t>
<section title="Designing for Operations and Management">
<t>The operational environment and manageability of the protocol should be considered from
the start when new protocols are designed.</t>
<t>Protocol designers should consider which operations and management needs are
relevant to their protocol, document how those needs could be addressed, and suggest 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.</t>
<t>When a WG considers operation and management functionality for a
protocol, the document should contain enough information to understand
how the protocol will be deployed and managed, but 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.</t>
</section>
<section title="This Document">
<t>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.</t>
<t>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 is a decision that can be
made from case to case.</t>
<t>This document does not impose a solution, or 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 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.</t>
<t>Any decision to make a Management Considerations section a mandatory publication
requirement for IETF documents is the responsibility of the IESG, or
specific area directors, or working groups, and this document avoids
recommending any mandatory publication requirements. For a complex
protocol, a completely separate draft on operations and management might
be appropriate, or even a completely separate WG effort.</t>
<t>This document discusses the importance of considering operations and
management by setting forth a list of guidelines and a checklist
of questions to consider, which a protocol designer or reviewer can use to evaluate whether
the protocol and documentation address common operations and
management needs. Operations and management are highly dependent on their
environment, so most guidelines are subjective rather than objective.</t>
<!--
<t>This document provides some objective criteria to promote interoperability
through the use of standard management interfaces, such as "did you
design counters in a MIB module for monitoring packets in/out of an
interface?" <xref target="RFC2863">The Interfaces Group MIB
</xref>, "did you write an XML-based
data model for configuring your protocol with Netconf?" <xref
target="RFC4741">NETCONF Configuration Protocol</xref>, and "did you standardize syslog message
content and structured data elements for reporting events that might
occur when operating your protocol?" <xref
target="I-D.ietf-syslog-protocol"></xref> and "did you consider appropriate notifications in case of failure situations?"</t>
-->
</section>
<section title="Motivation">
<t>For years the IETF community has used the IETF Standard
Management Framework, including the Simple Network Management Protocol <xref target="RFC3410"></xref>, the Structure of Management Informatiion <xref
target="RFC2578"></xref>, 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.</t>
<t>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.</t>
</section>
<section title="Background">
<t>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.</t>
<t>In 1988, the IAB published <xref target="RFC1052">IAB Recommendations for the Development of Internet Network Management Standards</xref> 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.</t>
<t>In 2001, OPS Area design teams were created to document
requirements related to configuration of IP-based networks. One output
was "Requirements for Configuration Management of IP-based Networks"
<xref target="RFC3139"></xref>.</t>
<t>In 2003, the Internet Architecture Board (IAB) held a workshop on
Network Management <xref target="RFC3535"></xref> that discussed the
strengths and weaknesses of some IETF network management protocols,
and compared them to operational needs, especially configuration.</t>
<t>One issue discussed was the user-unfriendliness of the binary
format of SNMP and <xref target="RFC3084">COPS Usage for Policy Provisioning (COPS-PR)</xref>, and it was
recommended that the IETF explore an XML-based Structure of Management
Information, and an XML-based protocol for configuration.</t>
<t>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.</t>
<t>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 doing network management.</t>
</section> <!-- background -->
<section title="Available Management Technologies" anchor="availmgmt">
<t>The IETF has a number of standard management technologies available. These include SNMP, SYSLOG, RADIUS, DIAMETER, NETCONF, IPFIX, and others. <!-- These protocol standards, pointers to the documents that define them, and standard information and data models for specific functionality, are described in "Survey of IETF Network Management Standards" <xref target="I-D.ietf-opsawg-survey-management"></xref> --></t>
</section> <!-- available -->
<section title="Terminology">
<t>This document deliberately does not use the (capitalized) keywords
described in <xref target="RFC2119">RFC 2119</xref>. 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 document is a set of
guidelines based on current practices of protocol designers and
operators. This document does not describe requirements, so the key
words from RFC2119 have no place here.</t>
<t><list style="symbols">
<t>CLI: Command Line Interface</t>
<t>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.</t>
<t>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.</t>
<t>"new protocol" includes new protocols, protocol extensions,
data models, or other functionality being designed.</t>
<t>"protocol designer" represents individuals and working groups
involved in the development of new protocols.</t>
</list></t>
</section> <!-- Terminology -->
</section> <!-- Introduction -->
<section anchor="opcons" title="Operational Considerations - How Will the New Protocol Fit Into the Current Environment?">
<t>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.</t>
<t>BGP flap damping <xref target="RFC2439"></xref> 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. </t>
<section title="Operations Model" anchor="opsmodel">
<t>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 the operational model related to the
applicability of the protocol in the Internet environments where it
will be deployed. </t>
<t>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.</t>
<t>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.</t>
<!--A human interface, such as a command line interface, is
useful for troubleshooting, while a programmatic interface is
important for managing multiple devices in a consistent manner, and
automating repetitive functions. Graphical user interfaces can help an
operator comprehend an overview of the network quickly (one picture is
worth a thousand words), but an operator may also require seeing the
raw data to better understand just what is happening in the network.
Ease of use is a key requirement for any network management technology
from the operators point of view. Protocol designers should consider how
various protocol choices might impact ease of use in different
scenarios. -->
<t>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.</t>
</section>
<section title="Installation and Initial Setup" anchor="opsinstall">
<t>Anything that can be configured can be misconfigured. "Architectural Principles of the Internet" <xref target="RFC1958"></xref> Section 3.8 states: "Avoid
options and parameters whenever possible. Any options and parameters
should be configured or negotiated dynamically rather than manually."</t>
<t>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.</t>
<t>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.</t>
<t>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".
</t>
<t>it is extremely important to set a sensible default value for
all parameters</t>
<t>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)</t>
<t>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.</t>
</section>
<section title="Migration Path" anchor="opsmig">
<t>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 co-existence 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 co-exist in
the network with the new protocol?</t>
<t>Many protocols benefit from being incrementally deployable - operators may deploy aspects of a protocol before deploying the protocol fully.</t>
</section>
<section title="Requirements on Other Protocols and Functional Components" anchor="opsdep">
<t>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.</t>
<t>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.</t>
<t>For example, the design of <xref target="RFC2205">Resource ReSerVation Protocol (RSVP)</xref>
required each router to look at the RSVP PATH message, and if the router
understood RSVP, to add its own address to the message to
enable automatically 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. Router alert has its own problems in impacting router performance.</t>
</section>
<section title="Impact on Network Operation" anchor="opsimpact">
<t>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.</t>
<t>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.</t>
<t>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 result of the changes in
the operational model, such as servers performing auto-configuration
operations.</t>
<t>The protocol designer should consider also the impact on
infrastructure applications like <xref
target="RFC1034">DNS</xref>, the registries, or the size of routing
tables. For example, <xref target="RFC5321">Simple Mail Transfer Protocol (SMTP)</xref> 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 the DNS cache resolver overload.</t>
<t>The impact on performance may also be noted - increased delay or
jitter in real-time traffic applications, or response time in
client-server applications when encryption or filtering are
applied.</t>
<t>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.</t>
</section>
<section title="Verifying Correct Operation" anchor="opsverify">
<t>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? </t>
<t>Having simple protocol status and health indicators on network devices is a
recommended means to check correct operation.</t>
</section>
</section>
<section title="Management Considerations - How Will The Protocol be Managed?">
<t>The considerations of manageability should start from describing the
operations model, which includes identifying the entities to be
managed, how the managed protocol is supposed to be installed,
configured and monitored. </t>
<t>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 <xref target="RFC3535"></xref> says, MIB modules
can often be characterized as a list of ingredients without a
recipe.</t>
<t>The management model should take into account
factors such as: <list style="symbols">
<t>what type of management entities will be involved (agents,
network management systems)?</t>
<t>what is the possible architecture (client-server,
manager-agent, poll-driven or event-driven, autoconfiguration,
two levels or hierarchical)?</t>
<t>what are the management operations - initial
configuration, dynamic configuration, alarm and exception
reporting, logging, performance monitoring, performance reporting,
debugging?</t>
<t>how are these operations performed - locally, remotely, atomic
operation, scripts? Are they performed immediately or time scheduled or event triggered?</t>
<!--
<t>what are the typical user interfaces - Command line (CLI) or
graphical user interface (GUI)?</t>
-->
</list></t>
<t>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.</t>
<t>Management needs to be considered not only from the perspective of a device, but also from the perspective of network and service management perspectives. 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.</t>
<t>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 <xref target="RFC4741"></xref> 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.</t>
<t>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.
</t>
<t>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.</t>
<section title="Interoperability" anchor="intermgmt">
<t>Just as when deploying protocols that will inter-connect devices,
our primary goal in considering management should be interoperability,
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 3rd party applications and the outsourcing of
management services.
</t>
<t>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 becomes a problem. It is 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.</t>
<t>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 the IETF likes this
or not. The IETF is moving from support for one schema language for modeling
the structure of management information (<xref target="RFC2578">Structure of Management Information Version 2 (SMIv2)
</xref>)
and one simple network
management protocol (<xref target="RFC3410">Simple Network Management Protocol (SNMP)</xref>) towards
support for additional schema languages and additional management protocols suited to
different purposes. Other Standard
Development Organizations (e.g. DMTF, 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
<list>
<t><xref target="W3C.REC-xmlschema-0-20010502">XML Schema Definition</xref></t>
<!--
<t><xref target="RelaxNG">Relax NG</xref></t>
<t><xref target="DSDL">Document Schema Definition Languages</xref></t>
-->
<t>and others</t>
</list>
and
<list>
<t><xref
target="RFC4741">NETCONF Configuration Protocol</xref></t>
<t><xref
target="RFC5101">IP Flow Information Export (IPFIX) Protocol
</xref>) for usage accounting </t>
<t><xref
target="RFC5424">The syslog Protocol</xref> for logging</t>
<t>and others</t>
</list>
</t>
<t>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 or models or releases of product.</t>
<t>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. For example, 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.</t>
<t>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 or a CLI
command or a SYSLOG message, the counter will have the same
meaning.</t>
<t>Protocol designers should consider which information might be
useful for managing the new protocol or protocol extensions.</t>
<figure title="Figure 1">
<preamble></preamble>
<artwork><![CDATA[ IM --> conceptual/abstract model
| for designers and operators
+----------+---------+
| | |
DM DM DM --> concrete/detailed model
for implementers
]]></artwork>
<postamble>Information Models and Data Models</postamble>
</figure>
<t>On the Difference between Information Models and Data Models <xref
target="RFC3444"> </xref> may be useful in determining what
information to consider regarding information models, as compared to
data models.</t>
<t>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:</t>
<t><list style="symbols">
<t><xref target="RFC3060"></xref> - Policy Core Information Model
version 1</t>
<t><xref target="RFC3290"></xref> - An Informal Management Model
for DiffServ Routers</t>
<t><xref target="RFC3460"></xref> - Policy Core Information Model
Extensions</t>
<t><xref target="RFC3585"></xref> - IPsec Configuration Policy
Information Model</t>
<t><xref target="RFC3644"></xref> - Policy Quality of Service
Information Model</t>
<t><xref target="RFC3670"></xref> - Information Model for
Describing Network Device QoS Datapath Mechanisms</t>
<t><xref target="RFC3805"></xref> - Printer MIB v2 contains both
an IM and a DM</t>
</list>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.</t>
<t></t>
</section>
<section title="Management Information" anchor="datamgmt">
<t>Languages used to describe an information model can influence the
nature of the model. Using a particular data modeling language, such as
the SMIv2, influence the model to use certain types of structures, such as
two-dimensional tables. This document recommends using English text (the
official language for IETF specifications) to describe an information model.
A sample data model could be developed to demonstrate the information
model.</t>
<t>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 should
an operator be notified.</t>
<t>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, and 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.</t>
<t>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.</t>
<t>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?</t>
<t>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 have an impact on fate sharing?</t>
<section title="Information Model Design">
<t> This document recommends keeping the information model as simple as
possible by applying the following criteria:
<list style="numbers">
<t>Start with a small set of essential objects and add only as
further objects are needed.</t>
<t> Require that objects be essential for management.</t>
<t> Consider evidence of current use and/or utility.</t>
<t>Limit the total number of objects.</t>
<t>Exclude objects that are simply derivable from others in this or
other information models.</t>
<t>Avoid causing critical sections to be heavily instrumented. A
guideline is one counter per critical section per layer.</t></list>
</t>
</section>
</section>
<section title="Fault Management" anchor="faultmgmt">
<t>The protocol designer should document the basic faults and health
indicators that need to be instrumented for the new protocol, and the
alarms and events that must be propagated to management applications
or exposed through a data model.</t>
<t>The protocol designer should consider how fault information will
be propagated. Will it be done using asynchronous notifications or
polling of health indicators?</t>
<t>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?</t>
<t>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?</t>
<section title="Liveness Detection and Monitoring">
<t>Liveness detection and monitoring applies both to the control
plane and the data plane. Mechanisms for detecting faults in the
control plane or for monitoring its liveness are usually built into
the control plane protocols or inherited from underlying data plane
or forwarding plane protocols. These mechanisms do not typically
require additional management capabilities. However, when a system
detects a control plane fault, there is often a requirement to
coordinate recovery action through management applications or at
least to record the fact in an event log. </t>
<t>Where the protocol is responsible for establishing data or user
plane connectivity, liveness detection and monitoring usually need
to be achieved through other mechanisms. In some cases, these
mechanisms already exist within other protocols responsible for
maintaining lower layer connectivity, but it will often be the case
that new procedures are required to detect failures in the data path
and to report rapidly, allowing remedial action to be taken.</t>
<t>Protocol designers should always build in basic testing features
(e.g. ICMP echo, UDP/TCP echo service, NULL RPC calls) that can be
used to test for liveness, with an option to enable and disable
them.</t>
</section>
<section title="Fault Determination">
<t>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.</t>
<t>How do you distinguish between faulty messages and good messages?</t>
<t>Would some threshold-based mechanisms, such as RMON events/alarms or the EVENT-MIB, be useable 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?</t>
</section>
<section title="Root Cause Analysis">
<t>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.</t>
</section>
<section title="Fault Isolation">
<t>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.</t>
</section>
</section>
<section title="Configuration Management" anchor="confmgmt">
<t>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.</t>
<t>What information should be maintained across reboots of the device,
or restarts of the management system?</t>
<t><xref target="RFC3139">"Requirements for Configuration Management of IP-based Networks"</xref> 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 do that for 1,000 devices.
</t>
<t>A number of efforts have existed in the IETF to develop
policy-based management. <xref target="RFC3198">"Terminology for Policy-Based Management"</xref> was
written to standardize the terminology
across these efforts.</t>
<!-- <t>It is highly desirable that text processing tools such as diff, and
version management tools such as RCS or CVS or SVN, can be used to
process configurations. This approach simplifies comparing the current
operational state to the initial configuration. It is commonplace to compare
configuration changes to e.g., last day, last week, last month, etc. Having
configuration in a text, and human-understandable format is very valuable
for various reasons such as change control (or verification), configuration
consistency checks, etc.</t>
<t>With structured text such as XML, simple text diffs may be found to
be inadequate and more sophisticated tools may be needed to make any
useful comparison of versions.</t>
-->
<t>Implementations should not arbitrarily modify configuration data.
In some cases (such as Access Control Lists) 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.</t>
<t>There are two parts to this: 1. An NMS system
could optimize access control lists (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.</t>
<t>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.</t>
<!--
<t>It is important to distinguish between the distribution of
configurations and the activation of a certain configuration. Devices
should be able to hold multiple configurations. NETCONF <xref
target="RFC4741"></xref>, for example, differentiates between the
"running" configuration and "candidate" configurations.</t>
-->
<t>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
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.</t>
<t>Consensus of the 2002 IAB Workshop <xref target="RFC3535"></xref> 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.</t>
<t>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.</t>
<t>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.</t>
<t>Many protocol specifications include timers that are used as part
of operation of the protocol. These timers should have default values
suggested in the protocol specification and may not need to be
otherwise configurable.</t>
<section title="Verifying Correct Operation">
<t>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, and
techniques for testing the effect that the protocol has had on the network
after being deployed. </t>
<t>Protocol designers should consider how to test the correct
end-to-end operation of the network, and how to verify the correct
data or forwarding plane function of each network element. This may be
achieved through status and statistical information from network devices. </t>
</section>
<section title="Control of Function and Policy ">
<t>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.</t>
</section>
</section>
<section title="Accounting Management" anchor="acctmgmt">
<t>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.</t>
<t><xref target="RFC2975">"Introduction to Accounting
Management"</xref> 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.</t>
</section>
<section anchor="perfmgmt" title="Performance Management">
<t>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. </t>
<t>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
recommendation describes the class of equipment, system, or service
being addressed; discuss the performance characteristics that are
pertinent to that class; clearly identify a set of metrics that aid in
the description of those characteristics; specify the methodologies
required to collect said metrics; and lastly, present the requirements
for the common, unambiguous reporting of benchmarking results.</t>
<t>Performance metrics may be useful in multiple environments, and for different protocols. The IP Performance Monitoring (IPPM) WG or Benchmarking (BMWG) WG may have already defined metrics that would be useful for the new protocol. 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 the current state. Snapshots are of less value for performance monitoring.</t>
<t>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).</t>
<section title="Monitoring the Protocol">
<t>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.</t>
<t>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.</t>
<t>Counter definitions should be unambiguous about what is included in the count, and what is not included in the count.</t>
<t>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?
</t>
<t>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. </t>
<t>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?</t>
<t>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.</t>
</section>
<section title="Monitoring the Device">
<t>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. </t>
<t>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. </t>
</section>
<section title="Monitoring the Network">
<t>Consider whether network performance will be affected
by the number of protocol entities being deployed. </t>
<t>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, the expected behaviors when a malformed message is
received.</t>
<t>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? </t>
</section>
<section title="Monitoring the Service">
<t>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?
</t>
</section>
</section>
<section anchor="secmgmt" title="Security Management">
<t>Protocol designers should consider how to monitor and to manage
security aspects and vulnerabilities of the new protocol.</t>
<t>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.</t>
<t>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?</t>
<t>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, or 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?</t>
<t>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.</t>
<t>Consider security threats that may be introduced by management operations. For example
CAPWAP breaks the structure of monolithic Access Points (AP) into Access
Controllers and Wireless Termination Points (WTP). 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.</t>
<t>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.</t>
<t>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.</t>
<t>Protocol designers should consider how to provide a secure
transport, authentication, identity, and access control which
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.</t>
<t>Protocol designers should consider how access control lists
are maintained and updated.</t>
<t>Standard SNMP notifications or SYSLOG messages <xref
target="RFC5424"></xref> 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 SSH from where, failed SSH logins can be
logged using syslog, etc.
</t>
<t>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.</t>
<!--
<t>RADIUS and DIAMETER can provide authentication and authorization. A
protocol designer should consider which attributes would be
appropriate for their protocol.</t>
removed in response to comment from Adrian: This paragraph is apropos of what? What are you trying to tell me?
Should I run my management using Radius? Should I try to build
Diameter into my new protocol?
-->
<t>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 (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.</t>
</section>
</section>
<section title="Documentation Guidelines">
<t>This document is focused on what to think about, and how to document
the considerations of the protocol designer.</t>
<section title="Recommended Discussions">
<t>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.</t>
<t>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.</t>
</section>
<section title="Null Manageability Considerations Sections">
<t>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 regarding the manageability of the protocol at the time of its
design.</t>
<t>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.</t>
<t>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.</t>
</section>
<section title="Placement of Operations and Manageability Considerations Sections ">
<t>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.</t>
</section>
</section>
<section title="IANA Considerations">
<t>This document does not introduce any new codepoints or name spaces
for registration with IANA. </t>
<t>Note to RFC Editor: this section may be
removed on publication as an RFC.</t>
</section>
<section title="Security Considerations">
<t>This document is informational and provides guidelines for
considering manageability and operations. It introduces no new security
concerns.</t>
<t>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.
</t>
<t>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.
</t>
<t>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.
</t>
<t>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 <xref target="secmgmt"></xref>).
</t>
</section>
<section title="Acknowledgements">
<t>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.</t>
<t>Some of the discussion about designing for manageability came from
private discussions between Dan Romascanu, Bert Wijnen, Juergen
Schoenwaelder, Andy Bierman, and David Harrington.</t>
<t>Thanks to reviewers who helped fashion this document, including
Adrian Farrell, David Kessens, Dan Romascanu, Ron Bonica, Bert Wijnen, Lixia Zhang,
Ralf Wolter, Benoit Claise, Brian Carpenter, Harald Alvestrand, Juergen
Schoenwaelder, and Pekka Savola.
</t>
</section>
</middle>
<back>
<references title="Informative References">
&rfc5321;
&rfc1034;
&rfc1052;
&rfc1958;
&rfc2119;
&rfc2205;
&rfc2439;
&rfc2578;
&rfc2975;
&rfc3060;
&rfc3084;
&rfc3139;
&rfc3198;
&rfc3290;
&rfc3410;
&rfc3444;
&rfc3460;
&rfc3535;
&rfc3585;
&rfc3644;
&rfc3670;
&rfc3805;
&rfc4741;
&rfc5101;
&rfc5424;
&W3C.REC-xmlschema-0-20010502;
</references>
<section title="Operations and Management Review Checklist">
<!-- start of checklist -->
<t>This appendix provides a quick checklist of issues that protocol designers
should expect operations and management expert reviewers to look for when reviewing
a document being proposed for consideration as a protocol standard.</t>
<section title="Operational Considerations">
<t>Has the operations model been discussed? see <xref target="opsmodel"></xref>
<list>
<t>Does the document include a description of the
operational model - how is this protocol or technology going to be
deployed and managed?</t>
<t>Is the proposed specification deployable? If not, how could it
be improved? </t>
<t>
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?</t>
<t>Are there any coexistence issues?</t>
</list></t>
<t>Has installation and initial setup been discussed? see <xref target="opsinstall"></xref>
<list>
<t>Is the solution sufficiently configurable? </t>
<t>Are configuration parameters clearly identified?</t>
<t>Are configuration parameters normalized?</t>
<t>Does each configuration parameter have a reasonable
default value? </t>
<t>Will configuration be pushed to a device by a
configuration manager, or pulled by a device from a configuration
server?</t>
<t>How will the devices and managers find and authenticate
each other?</t>
</list></t>
<t>Has the migration path been discussed? see <xref target="opsmig"></xref>
<list>
<t>Are there any backward compatibility issues?</t>
</list></t>
<t>Have the Requirements on Other Protocols and Functional Components been discussed? see <xref target="opsdep"></xref>.
<list>
<t>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?</t>
</list></t>
<t>Has the Impact on Network Operation been discussed? see <xref target="opsimpact"></xref>
<list>
<t>Will the new protocol significantly increase traffic load on existing networks?</t>
<t>Will the proposed management for the new protocol significantly increase traffic load on existing networks?</t>
<t>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?</t>
<t>Does the new protocol need supporting services (e.g. DNS or AAA) added to an existing network?</t>
</list></t>
<t>Have suggestions for verifying correct operation been discussed? see <xref target="opsverify"></xref>
<list>
<t>How can one test end-to-end connectivity and throughput?</t>
<t>Which metrics are of interest?</t>
<t>Will testing have an impact on the protocol or the network?</t>
</list></t>
<t>Has management interoperability been discussed? see <xref target="intermgmt"></xref>
<list>
<t>Is a standard protocol needed for interoperable management?</t>
<t>Is a standard information or data model needed to make properties comparable across devices from different vendors?</t>
</list></t>
<t>Are there fault or threshold conditions that should be reported? see <xref target="faultmgmt"></xref>
<list>
<t>Does specific management information have time utility?</t>
<t>Should the information be reported by notifications? polling? event-driven polling?</t>
<t>Is notification throttling discussed?</t>
<t>Is there support for saving state that could be used for root-cause analysis?</t>
</list>
</t>
<t>Is configuration discussed? see <xref target="confmgmt"></xref>
<list>
<t>Are configuration defaults, and default modes of operation considered?</t>
<t>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)?</t>
<t></t>
</list>
</t>
</section> <!-- /Operational Consierations -->
<section title="Management Considerations">
<t>Do you anticipate any manageability issues with the
specification?</t>
<t><list>
<t>Is Management interoperability discussed? see <xref target="intermgmt"></xref>
<list>
<t>Will it use centralized or distributed
management?</t>
<t>Will it require remote and/or local management
applications? </t>
<t>Are textual or graphical user interfaces required?</t>
<t>Is textual or binary format for management information preferred?</t>
</list>
</t> <!-- /4.1 -->
<t>Is Management Information discussed? see <xref target="datamgmt"></xref>
<list>
<t>What is the minimal set of management
(configuration, faults, performance monitoring) objects that need to be
instrumented in order to manage the new protocol?</t>
</list>
</t> <!-- /4.2 -->
<t>Is Fault Management discussed? see <xref target="faultmgmt"></xref>
<list>
<t>Is Liveness Detection and Monitoring discussed?</t>
<t>Does the solution have failure modes that are difficult to
diagnose or correct? Are faults and alarms reported and
logged?</t>
<t></t>
</list>
</t> <!-- /4.3 -->
<t>Is Configuration Management discussed? see <xref target="confmgmt"></xref>
<list>
<t>Is protocol state information exposed to the user? How? are
significant state transitions logged?</t>
<t></t>
</list>
</t> <!-- /4.4 -->
<t>Is Accounting Management discussed? see <xref target="acctmgmt"></xref>
<list>
<t></t>
</list>
</t> <!-- /4.5 -->
<t>Is Performance Management discussed? see <xref target="perfmgmt"></xref>
<list>
<t>Does the protocol have an impact on network traffic and network
devices? Can performance be measured? </t>
<t>Is protocol performance
information exposed to the user?</t>
</list>
</t> <!-- /4.6 -->
<t>Is Security Management discussed? see <xref target="secmgmt"></xref>
<list>
<t>Does the specification discuss how to manage aspects of security, such as
access controls, managing key distribution, etc.</t>
<t></t>
</list>
</t> <!-- /4.7 -->
</list></t>
</section> <!-- /management considerations -->
<section title="Documentation">
<t>Is an operational considerations and/or manageability section part of the document?</t>
<t>Does the proposed protocol have a significant operational
impact on the Internet?</t>
<t>Is there proof of implementation and/or operational experience?</t>
</section>
</section>
<!--
***************************** end of checklist *****************************
-->
<section title="Change Log">
<t>-- Note to RFC Editor: Please remove this section upon publication as an RFC</t>
<t>Changes from opsawg-05 to opsawg-06</t>
<t><list>
<t>Spelling and grammar corrections</t>
<t>Addressed comments from WGLC.</t>
<t>Editorial comments</t>
<t>Addressed most comments from Randy Bush, Bert Wijnen, Adrian Farrel, </t>
<t>Removed IETF Management Framework section.</t>
<t>Added discussion of standard protocols.</t>
</list></t>
<t>Changes from opsawg-04 to opsawg-05</t>
<t><list>
<t>added bullets for appendix checklist</t>
<t>aligned checklist order and guidelines order</t>
<t>resolved all DISCUSS and TODO issues.</t>
</list></t>
<t>Changes from opsawg-03 to opsawg-04</t>
<t><list>
<t>improved wording in Introduction</t>
<t>added a number of DISCUSS points raised during WG reviews</t>
<t>added more wording on service management</t>
<t>updated references and copyrights</t>
</list></t>
<t>Changes from opsawg-02 to opsawg-03</t>
<t>From reviews by Lixia Zhang and feedback from WG Chairs' Lunch.</t>
<t><list>
<t>added discussion of impact on the Internet to checklist</t>
<t>spell check</t>
<t>added examples</t>
<t>added discussion of default values</t>
<t>added discussion of database-driven configuration</t>
<t>fixed some references</t>
<t>expanded the checklist</t>
</list></t>
<t>Changes from opsawg-01 to opsawg-02</t>
<t><list>
<t>moved survey of protocols and data models to separate
document</t>
<t>changed "working group" to "protocol designer" throughout, as
applicable.</t>
<t>modified wording from negative to positive spin in places.</t>
<t>updated based on comments from Ralf Wolter and David Kessens</t>
</list></t>
<t>Changes from opsawg-00 to opsawg-01</t>
<t><list>
<t>moved Proposed Standard data models to appendix</t>
<t>moved advice out of data model survey and into considerations
section</t>
<t>addressed comments from Adrian and Dan</t>
<t>modified the Introduction and Section 2 in response to many
comments.</t>
<t>expanded radius and syslog discussion, added psamp and VCCV,
modified ipfix,</t>
</list></t>
<t>Changes from harrington-01 to opsawg-00</t>
<t><list>
<t>added text regarding operational models to be managed.</t>
<t>Added checklist appendix (to be filled in after consensus is
reached on main text )</t>
</list></t>
<t>Changes from harrington-00 to harrington-01</t>
<t><list>
<t>modified unclear text in "Design for Operations and
Management"</t>
<t>Expanded discussion of counters</t>
<t>Removed some redundant text</t>
<t>Added ACLs to Security Management</t>
<t>Expanded discussion of the status of COPS-PR, SPPI, and PIBs.</t>
<t>Expanded comparison of RADIUS and Diameter.</t>
<t>Added placeholders for EPP and XCAP protocols.</t>
<t>Added Change Log and Open Issues</t>
</list></t>
</section>
</back>
</rfc>| PAFTECH AB 2003-2026 | 2026-04-23 09:00:16 |