Internet DRAFT - draft-hares-netconf-i2rs-protocol
draft-hares-netconf-i2rs-protocol
I2RS working group S. Hares
Internet-Draft Huawei
Intended status: Informational A. Dass
Expires: May 19, 2017 Ericsson
November 15, 2016
NETCONF Changes to Support I2RS Protocol
draft-hares-netconf-i2rs-protocol-00.txt
Abstract
This document describes a NETCONF capabiilty to support the Interface
to Routing system (I2RS) protocol requirements for I2RS protocol
version 1. The I2RS protocol is a re-use higher layer protocol which
defines extensions to other protocols (NETCONF and RESTCONf) and
extensions to the Yang Data Modeling language.
The I2RS protocol supports ephemeral state datastores as control
plane datastores. Initial versions of this document contain
descriptions of the ephemeral datastore. Future versions may move
this description to NETMOD datastore description documents.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 19, 2017.
Copyright Notice
Copyright (c) 2016 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
Hares & Dass Expires May 19, 2017 [Page 1]
Internet-Draft I2RS Protocol Yang November 2016
publication of this document. Please review these documents
carefully, as 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 Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Definitions Related to Ephemeral Configuration . . . . . . . 4
2.1. Requirements language . . . . . . . . . . . . . . . . . . 4
2.2. I2RS Definitions . . . . . . . . . . . . . . . . . . . . 4
3. Overview of Changes . . . . . . . . . . . . . . . . . . . . . 6
3.1. I2RS protocol requirements . . . . . . . . . . . . . . . 6
3.2. NETCONF Features and Extensions . . . . . . . . . . . . . 7
3.3. RESTCONF features and Extensions . . . . . . . . . . . . 8
3.4. Assumptions on Data Store Model Melee . . . . . . . . . . 8
4. NETCONF protocol extensions for the ephemeral datastore . . . 9
4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2. Dependencies . . . . . . . . . . . . . . . . . . . . . . 10
4.3. Capability identifier . . . . . . . . . . . . . . . . . . 11
4.4. New Operations . . . . . . . . . . . . . . . . . . . . . 11
4.5. Modification to existing operations . . . . . . . . . . . 11
4.5.1. <get-config> . . . . . . . . . . . . . . . . . . . . 11
4.5.2. <edit-config> . . . . . . . . . . . . . . . . . . . . 12
4.5.3. <copy-config> . . . . . . . . . . . . . . . . . . . . 13
4.5.4. <delete-config> . . . . . . . . . . . . . . . . . . . 13
4.5.5. <lock> and <unlock> . . . . . . . . . . . . . . . . . 13
4.5.6. <get> . . . . . . . . . . . . . . . . . . . . . . . . 13
4.5.7. <close-session> and <kill-session> . . . . . . . . . 13
4.6. Interactions with Capabilities . . . . . . . . . . . . . 13
4.6.1. writable-running and candidate datastore . . . . . . 14
4.6.2. confirmed commmit . . . . . . . . . . . . . . . . . . 14
4.6.3. rollback-on-error . . . . . . . . . . . . . . . . . . 14
4.6.4. validate . . . . . . . . . . . . . . . . . . . . . . 14
4.6.5. Distinct Startup Capability . . . . . . . . . . . . . 15
4.6.6. URL capability and XPATH capability . . . . . . . . . 15
5. Ephemeral Data (Background) . . . . . . . . . . . . . . . . . 15
5.1. Ephemeral Control Plane Datastore . . . . . . . . . . . . 16
5.2. Qualities of Ephemeral Datastore . . . . . . . . . . . . 17
5.3. I2RS Agent Caching of Ephemeral Data . . . . . . . . . . 18
5.4. Massive Amounts of Configuration Data . . . . . . . . . . 18
5.5. Write Error handling . . . . . . . . . . . . . . . . . . 19
5.5.1. Normal validation checks . . . . . . . . . . . . . . 19
5.6. IPFIX for traffic monitoring . . . . . . . . . . . . . . 20
5.7. Binary encoding of RESTCONF/NETCONF . . . . . . . . . . . 20
5.8. Ephemeral state in DDoS environments . . . . . . . . . . 20
Hares & Dass Expires May 19, 2017 [Page 2]
Internet-Draft I2RS Protocol Yang November 2016
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
7. Security Considerations . . . . . . . . . . . . . . . . . . . 20
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.1. Normative References: . . . . . . . . . . . . . . . . . . 21
9.2. Informative References . . . . . . . . . . . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25
1. Introduction
This a proposal for yang additions to support the first version of
the I2RS protocol.
The I2RS architecture [RFC7921] defines the I2RS interface "a
programmatic interface for state transfer in and out of the Internet
routing system". The I2RS protocol is a protocol designed to a
higher level protocol comprised of a set of existing protocols which
have been extended to work together to support a new interface to the
routing system. The I2RS protocol is a "reuse" management protocol
which creates new management protocols by reusing existing protocols
and extending these protocols for new uses, and has been designed to
be implemented in phases [RFC7921].
The first version of the I2RS protocol is comprised of extensions to
existing features of NETCONF [RFC6241] and RESTCONF
[I-D.ietf-netconf-restconf]. The data modeling language for the I2RS
protocol will be Yang [RFC7950] with features and extensions proposed
in this draft.
The structure of this document is:
Section 2 provides definitions for terms in this document.
Section 3 summarizes the changes to configuration data store,
NETCONF, RESTCONF, and YANG.
[I-D.ietf-i2rs-ephemeral-state] specifies the I2RS requirements
for the ephemeral state. Section 4 discusses how these
requirements might be implemented in a control plane datastore.
Section 5 describes the one required Yang model addition for I2RS
(ephemeral key word). This section also describes elements of
information in the NETCONF/RESTCONF implementations that must be
queryable by the I2RS protocol implementations.
Hares & Dass Expires May 19, 2017 [Page 3]
Internet-Draft I2RS Protocol Yang November 2016
2. Definitions Related to Ephemeral Configuration
This section reviews definitions from I2RS architecture [RFC7921] and
NETCONF operational state definitions
[I-D.nmdsdt-netmod-revised-datastores] before using these to
construct a definition of the ephemeral data store.
2.1. Requirements language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2.2. I2RS Definitions
The I2RS architecture [RFC7921] defines the following terms:
ephemeral data: is data which does not persist across a reboot
(software or hardware) or a power on/off condition. Ephemeral
data can be configured data or data recorded from operations of
the router. Ephemeral configuration data also has the property
that a system cannot roll back to a previous ephemeral
configuration state. (See [RFC7921] for an architectural
overview, [I-D.ietf-i2rs-ephemeral-state] for requirements, and
[I-D.nmdsdt-netmod-revised-datastores] for discussion of how the
ephemeral datastore as a control plane datastore interacts with
intended datstore and dynamic configuration protocols to form the
applied datastore".
local configuration: is the data on a routing system which does
persist across a reboot (software or hardware) and a power on/off
condition. Local configuration has the ability to roll back to a
pervious configuration state. Local configuration is defined as
the intended datastore [I-D.nmdsdt-netmod-revised-datastores]
which is modified by dynamic configuration protocols (such as
DHCP) and the I2RS ephemeral data store
dynamic configuration protocols datastore are configuration
protocols such as DHCP that interact with the intended datastore
(which does persist across a reboot (software or hardware) power
on/off condition), and the I2RS ephemeral state control plane
datastore.
operator-applied policy: is a policy that an operator sets that
determines how the ephemeral datastore as a control plane data
store interacts with applied datastore (as defined in
[I-D.nmdsdt-netmod-revised-datastores]). This operator policy
consists of policy knobs that the operator sets to determine how
Hares & Dass Expires May 19, 2017 [Page 4]
Internet-Draft I2RS Protocol Yang November 2016
the I2RS agent control plane ephemeral state datastore will
interact with the intended configuration datastor and the dynamic
configuration protocol datastore. Three policy knobs could be
used to implement this policy:
* policy knob 1: I2RS Ephemeral control-plane datastore takes
takes precedence over the intended datastore in the routing
protocols.
* policy knob 2: Updated intended configuration datastore takes
precedence over the I2RS ephemeral control-plane data store in
the routing protocols
* policy knob 3: Ephemeral control plane datastore takes
precedence over any other dynamic configuration protocols
datastore.
An practical example for three states of the operator-applied policy
may help the reader understand the concept. Consider the following
three desired outcomes with their policy knob states:
Monitoring Features only The policy knob settings are:
Policy knob 1=false,
policy knob 2=true,
Policy knob 3=false,
Action: I2RS protocol software feature is installed, but the
operator does not want the I2RS ephemarl datastore to take
precedence (that is be used) on any variables in the applied
configuration datastore. This policy set might be valid if I2RS
is only suppose to monitor data on this node through newly defined
parameters.
I2RS Agent Changes win the policy knob settings would be:
Policy knob 1=true,
policy knob 2=false,
Policy knob 3=false,
Action: This is the normal case for the I2RS Agent where the
ephemeral control-plane datastore takes precedence over the
intended configuration datastore and dynamic configuration
datastores. The values from the I2RS ephemearl datastore are used
Hares & Dass Expires May 19, 2017 [Page 5]
Internet-Draft I2RS Protocol Yang November 2016
rather than the intended configuration datastore and the dynamic
configuration protocol datastore. When the ephemeral data is
removed by the I2RS agent, the dyanmic configuration datastore and
the intended configuration datastore state is restored, combined
and passed to the routing protocols for application.
Just change until next configuration update the policy knob settings
would be:
Policy knob 1=true,
policy knob 2=true,
Policy knob 3=false,
Action: This case can occur if the I2RS Client write to the
ephemeral control plane data store is only suppose to take
precedence until the next configuration cycle from a centralized
system. Suppose the local configuration is get by the centralized
system at 11:00pm each night. The I2RS Client writes temporary
changes to the routing system via the I2RS agent ephemeral write.
At 11:00pm, the local configuration update overwrite the
ephemeral. The I2RS Agent notifies the I2RS Client which is
tracking which of the ephemeral changes are being overwritten.
3. Overview of Changes
This oveview reviews the following:
o What NETCONF [RFC6241] protocol existing features required for
I2RS protocol and what extension for these extension features that
are needed for the I2RS protocol version 1,
o What RESTCONF [I-D.ietf-netconf-restconf] protocol existing
features are required for the I2RS protocol and what extensions
are needed for I2RS protocol version 1.
o An overview of the Yang 1.1 data modeling language[RFC7950]
features are needed for I2RS protocol version 1.
o An overview of the extensions to Yang 1.1 data modeling language
[RFC7950] that are needed for the I2RS protocol version 1.
3.1. I2RS protocol requirements
The requirements for the I2RS protocol are defined in the following
documents:
Hares & Dass Expires May 19, 2017 [Page 6]
Internet-Draft I2RS Protocol Yang November 2016
o I2RS Problem Statement [RFC7920],
o I2RS Architecture [RFC7921],
o I2RS Traceability [RFC7922],
o Publication and Subscription [RFC7923],
o I2RS Ephemeral State Requrements, ,
[I-D.ietf-i2rs-ephemeral-state]
o I2RS Protocol Security Requirements,
[I-D.ietf-i2rs-protocol-security-requirements]
The Interface to the routing System (I2RS) creates a new capability
for the routing systems, and with greater capaiblities come a greater
need for security. The requirements for a secure environment for
I2RS is described in [I-D.ietf-i2rs-security-environment-reqs].
3.2. NETCONF Features and Extensions
The features the I2RS protocol requires are:
o NETCONF [RFC6241] with its updates [RFC7803],
o Network Access Control Model [RFC6536] with update (draft-bierman-
netconf-rf6536bis)
o Running NETCONF over TLS with mutually X.509 authentication
[RFC7589]
o Keystore Model [I-D.ietf-netconf-keystore],
o Subscribing to Yang Datastore updates
[I-D.ietf-netconf-yang-push],
o NETCONF support for Event Notifications
[I-D.ietf-netconf-netconf-event-notifications],
o Subscribing to NETCONF Events (updated)
[I-D.ietf-netconf-rfc5277bis]
o Yang Patch Media type [I-D.ietf-netconf-yang-patch],
o NETCONF/RESTCONF Zero Touch provisioning
[I-D.ietf-netconf-zerotouch],
o TLS Client and Server Models [I-D.ietf-netconf-tls-client-server]
Hares & Dass Expires May 19, 2017 [Page 7]
Internet-Draft I2RS Protocol Yang November 2016
o Call Home [I-D.ietf-netconf-call-home],
o Module library [RFC7895],
o NETCONF/RESTCONF Zero Touch provisioning
[I-D.ietf-netconf-zerotouch],
3.3. RESTCONF features and Extensions
This protocol strawman utilizes the following existing proposed
features for NETCONF and RESTCONF
o RESTCONF [I-D.ietf-netconf-restconf]
o Module library [RFC7895],
o Publication/Subscription via Push [I-D.ietf-netconf-yang-push],
o Patch [I-D.ietf-netconf-yang-patch],
o syslog yang module (both [RFC5424] and
[I-D.ietf-netmod-syslog-model]
3.4. Assumptions on Data Store Model Melee
The NETMOD Working Group has been working to create new definitions
of datastores based on feedback from operators on desiring a split
between operational state and configuration state.
This document takes [I-D.nmdsdt-netmod-revised-datastores] as the
current status of the datastore discussion on configuration state,
operational state, ephemeral state changes (via I2RS), and routing
protocol state. The following things need to be carefully defined in
this work:
What is a dynamic configuration protocol (is it I2RS or DHCP)
What is a control-plane datastore - (ephemeral state only or
others? )
How to express the policy knobs that provide preference between
intended configuration, control plane datstore, and dynamic
configuration protocols
How does operational state allow for operational state to be
defined by ephemeral-only data models, and mixed (ephemeral +
intended configuration)
Hares & Dass Expires May 19, 2017 [Page 8]
Internet-Draft I2RS Protocol Yang November 2016
[I-D.nmdsdt-netmod-revised-datastores] is making good progress, but
these additional details need to be tied down.
4. NETCONF protocol extensions for the ephemeral datastore
capability-name: ephemeral-datastore
4.1. Overview
This capability defines the NETCONF protocol extensions for the
ephemeral state. The ephemeral state has the following features:
o the ephemeral data store is a part of the intended configuration
datastore, applied configuration datastore, and the derived state
store whose components are not survive a reboot.
o The ephemeral capability is signalled as a capability of a leaf,
grouping, a sub-module, or module that is stored as a feature of
the module in the netconf yang module library ([RFC7895]) used by
Yang 1.1 and RESTCONF and NETCONF.
o ephemeral data will be noted by an "ephemeral" statement in for a
leaf, grouping, sub-module, or module.
o The ephemeral datastore is never locked.
o The ephemeral data store is one pane of glass that overrides the
local configuration (which is considered one pane of glass) in the
intended config based on operator-applied policy knobs (see
section 2.1).
o Ephemeral data can occur as part of protocol or protocol
independent modules. However, ephemeral data nodes cannot have
non-ephemeral data nodes within the subtree. Ephemeral sub-
modules cannot have non-ephemeral data nodes within the module.
Ephemeral modules cannot have non-ephemeral sub-modules or nodes
within the module. Yang 1.1 [RFC7950] augmented by ephemeral
state must enforce this restriction. Similarly, the Yang mount
schema [I-D.ietf-netmod-schema-mount] must check for this
restriction.
o Ephemeral writes should enforce the normal validation checks,
priority pre-emption error handling if multiple I2RS clients write
the same data, and "all-or-nothing" error handling for multiple
actions in a write for data in groupings or orthogonal data (see
section 3.4). The I2RS agent should send the I2RS client
requesting write the notification of any type of error during the
write process: failure of normal validation, priority pre-emption
Hares & Dass Expires May 19, 2017 [Page 9]
Internet-Draft I2RS Protocol Yang November 2016
causing failure to write, multiple actions causing failure to
sustain write (aka all-or-nothing roll-back). If the I2RS agent
allows a priority pre-emption of the write of data model value by
an I2RS client (e.g. client 1) of another I2RS client (e.g. client
2), then the I2RS agent must send a notification of the I2RS pre-
emption to the previous I2RS client (e.g. client 2).
o Ephemeral writes as part of an rpc should allow the rpc to skip
normal validation checks if data model specifies "ephemeral-
validation nocheck;". The rpc which skips the normal validation
MUST resolve the pre-emption write error handling for any data
being written without normal validation check, and MUST only all
the data within a grouping rather than orthogonal data.
4.2. Dependencies
The following are the dependencies for ephemeral support:
o The Yang "ephemeral definition"
o The following NETCONF features:
* NETCONF [RFC6241] with its updates [RFC7803],
* Network Access Control Model [RFC6536] with update by (daft-
bierman-netconf-rf6536bis)
* Running NETCONF over TLS with mutually X.509 authentication
[RFC7589]
* Keystore Model [I-D.ietf-netconf-keystore],
* Subscribing to Yang Datastore updates
[I-D.ietf-netconf-yang-push],
* NETCONF support for Event Notifications
[I-D.ietf-netconf-netconf-event-notifications],
* Subscribing to NETCONF Events (updated)
[I-D.ietf-netconf-rfc5277bis]
* Yang Patch Media type [I-D.ietf-netconf-yang-patch],
* NETCONF/RESTCONF Zero Touch provisioning
[I-D.ietf-netconf-zerotouch],
* TLS Client and Server Models
[I-D.ietf-netconf-tls-client-server]
Hares & Dass Expires May 19, 2017 [Page 10]
Internet-Draft I2RS Protocol Yang November 2016
* Call Home [I-D.ietf-netconf-call-home],
* Module library [RFC7895],
* NETCONF/RESTCONF Zero Touch provisioning
[I-D.ietf-netconf-zerotouch],
4.3. Capability identifier
The ephemeral-datastore capability is identified by the following
capability string: (capability uri)
4.4. New Operations
None
4.5. Modification to existing operations
The capability for :ephemeral-datastore modifies the target for
existing operations.
4.5.1. <get-config>
The :ephemeral-datastore capability modifies the <edit-config> to
accept the <ephemeral> as a target for source, and allows the filters
focused on a particular module, submodule, or node.
The positive and negative responses remain the same.
Example - retrieve users subtree from
ephemeral database
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get-config>
<source>
<emphemeral-datastore/>
</source>
<filter type="subtree">
<top xmlns="http://example.com/schema/1.0/thermostat/config">
<desired-temp>
</top>
</filter>
</get-config>
</rpc>
Hares & Dass Expires May 19, 2017 [Page 11]
Internet-Draft I2RS Protocol Yang November 2016
4.5.2. <edit-config>
The :ephemeral-datastore capability modifies the <edit-config> to
accept the <ephemeral> as a target for source with filters. The
operations of merge, replace, create, delete, and remove are
available, but each of these operations is modified by the priority
write as follows:
<merge> parameter is replaced by <merge-priority> The current data
is modified by the new data in a merge fashion only if existing
data either does not exist, or is owned by a lower priority
client. If any data is replaced, this event is passed to the
notification function within the pub/sub and traceability.
<replace> is replaced by <replace-priority> for ephemeral
datastore which replaces data if the existing data is owned by a
lower priority client. If data any data is replaced, this event
is passed to the notification function within pub/sub and
traceability for notification to the previous client. The success
or failure of the event is passed to traceabilty.
<create> - the creation of the data node works as in [RFC6241]
except that the success or failure is passed to pub/sub and
traceability functions.
<deletion> - the deletion of the data node works as in [RFC6241]
except event that the success or the error event is passed to the
notiication services in the pub/sub and traceability functions.
<remove> - the remove of the data node works as in [RFC6241]
except that all results are forwarded to traceabilty.
The existing parameters are modified as follows:
<target> - add a target of :emphemeral-datastore
<default-operation> -allows only <merge-priority> or <replace-
priority>
<error-option> - the I2RS agent agent supports only the a"all-or-
nothing" equivalent to a "rollback-on-error" function.
positive response - the <ok> is sent for a positive response
within an <rpc-reply>.
negative response - the <rpc-error> is sent for a negative
response within an <rpc-reply>. Note a negative respones may
evoke a publication of an event.
Hares & Dass Expires May 19, 2017 [Page 12]
Internet-Draft I2RS Protocol Yang November 2016
4.5.3. <copy-config>
Copy config allows for the complete replacement of all the ephemeral
nodes within a target. The alternation is that source is the
:ephemeral datastore with the filtering to match the datastore. The
following existing parameters are modified as follows:
<target> - add a target of :emphemeral-datastore
<error-option> - the I2RS agent agent supports only the a"all-or-
nothing" equivalent to a "rollback-on-error" function.
positive response - the <ok> is sent for a positive response
within an <rpc-reply>.
negative response - the <rpc-error> is sent for a negative
response within an <rpc-reply>.
4.5.4. <delete-config>
The delete will delete all ephemeral nodes out of a datastore. The
target parameter must be changed to allow :ephemeral-datastore. and
filters.
4.5.5. <lock> and <unlock>
Lock and unlock are not supported with a target of :ephemeral-
datastore.
4.5.6. <get>
The <get> is altered to allow a target of :ephemeral-datastore and
with the filters.
4.5.7. <close-session> and <kill-session>
The close session is modified to take a target of :ephemeral-
datastore, Since no locks are set, none should be released.
The kill session is modified to take a target of "ephemeral-
datastore. Since no locks are set, none should be released.
4.6. Interactions with Capabilities
[RFC6241] defines NETCONF capabilities for writeable-running
datastore, candidate config data store, confirmed commit, rollback-
on-error, validate, distinct start-up, URL capability, and XPATH
Hares & Dass Expires May 19, 2017 [Page 13]
Internet-Draft I2RS Protocol Yang November 2016
capability. I2RS ephemeral state does not impact the writeable-
running data store or the candiate config datastore.
4.6.1. writable-running and candidate datastore
The writeable-running and the candidate datastore cannot be used in
conjunction with the ephemeral data store. Ephemeral database
overlays an intended configuration, and does not impact the writable-
running or candidate data store.
4.6.2. confirmed commmit
Confirmed commit capability is not supported for the ephemeral
datastore.
4.6.3. rollback-on-error
The rollback-on-error when included with ephemeral state allows the
error handling to be "all-or-nothing" (roll-back-on-error).
4.6.4. validate
The validation function operates normally with one addition with one
addition for any data handled by an rpc with "ephemeral-validation
nocheck".
The rpc specifying ephemeral-validation nocheck MUST specify within
the ephemeral data written by the rpc function the following
grouping:
Hares & Dass Expires May 19, 2017 [Page 14]
Internet-Draft I2RS Protocol Yang November 2016
grouping ephemeral-validation-notcheck {
leaf rpc {
type string rpc-id;
description "rpc wrote
the non-check data";
}
leaf rpc-seq {
type uint32 rpc-id;
description "sequence number of
rpc that wrote non-check data";
}
leaf client-id {
type uint64 client-id;
description "client identifier
that wrote non-checking rpc;"
}
description "Tracking on rpc with
no validation checking so validation
failure can send note to client.";
};
If the data validation finds an error in a component that was non-
check, the notification should include the data module, submodule (if
valid).
(Editor's note: Initial experiments on this type of rpc for I2RS RIB
routes and I2RS FB-RIB filters will be done before IETF 96.
4.6.5. Distinct Startup Capability
This NETCONF capability appears to operate to load write-able running
config, running-config, or candidate datastore. The ephemeral state
does not change the environment based on this command.
4.6.6. URL capability and XPATH capability
The URL capabilities specify a <url> in the <source> and <target>.
The initial suggestion to allow both of these features to work with
ephemeral datastore.
5. Ephemeral Data (Background)
Note: This section probably goes with the definition of ephemeral
state or as its own Draft
This section provides an overview of the ephemeral data store as a
control plane datastore and discusses several concepts that
Hares & Dass Expires May 19, 2017 [Page 15]
Internet-Draft I2RS Protocol Yang November 2016
implementers need to consider and provide feedback on. The concepts
include basic ephemeral datastore concepts, I2RS caching of ephemeral
data, issues for massive data flow, error handling (normal and
reduced), use of IPFIX or Binary for carrying I2RS ephemeral data,
and ephemeral state
This section augments [I-D.nmdsdt-netmod-revised-datastores] to begin
to discuss how the ephemeral state comtrol-plane datastore might be
implemented. The purpose of this section is to gather implementer
wisdom on the ephemeral datastore into one place. This section
discusses:
Ephemeral state as a control plane data store
Qualities of ephemeral datastores
Need to support Massive amounts of configuration data,
Two types of Error handling (regular, reduced)
Should we support link to IPFIX in I2RS protocol and ephemeral
state?
Binary encoding for RESTCONF/NETCONF
Ephemeral state in DDoS environments.
[I-D.ietf-i2rs-ephemeral-state] describes the requirements for I2RS
ephemeral state.
This section augments [I-D.nmdsdt-netmod-revised-datastores] to begin
to discuss how the ephemeral state comtrol-plane datastore might be
implemented. This initial draft refines the general description so
that early I2RS ephemeral state implementations may progress.
5.1. Ephemeral Control Plane Datastore
[I-D.nmdsdt-netmod-revised-datastores] architecture suggests that the
applied configuration is the combination of intended datastore, the
dynamic configuration protocols, and the control-plane datastores.
As described above, there are policy knobs which allow the I2RS Agent
to handle deciding what specific configuration variables is installed
in protocols (E.g BGP) or protocol independent functions (RIB or
Filters). In addition, the control-plane datastore may store the
parameters need to provide publication of events, statistics,
telementry within the ephemeral control-plane datastore.
Hares & Dass Expires May 19, 2017 [Page 16]
Internet-Draft I2RS Protocol Yang November 2016
The ephemeral data-store may have models which learn operational
state and augment it by configuration. For example
[I-D.ietf-i2rs-yang-l3-topology] uploads ospf and isis topology
information from the routing system and allows configuration of
additional links or nodes.
This new architecture is a multiple panes-of-glass model where the
decision on what value is chosen is based on policy. The extension
of this model is that it is possible for two or more of the control-
plane datastores to be ephemeral. If this occurs, then the policy
knobs must define the how the 2+ ephemeral datastores interact with
each other and the configuration state.
5.2. Qualities of Ephemeral Datastore
Note: The requirements for ephemeral state are in:
[I-D.ietf-i2rs-ephemeral-state]).
This section provides a discussion so that implementers writing code
for these datastores can discuss what needs to be standardized and
what does not need to be standardized.
The ephemeral data store has the following general qualities:
1. Ephemeral state is not unique to I2RS work.
2. The ephemeral datastore is never locked.
3. The ephemeral portion of the intended configuration, applied
state, and derived state does not persist over a reboot,
4. an ephemeral node cannot roll-back to its previous value,
5. Since ephemeral data store is just data that does not presist
over a reboot, then in theory any node or group of nodes in a
YANG data model could be ephemeral. The YANG data module must
indicate what portion of the data model (if any) is ephemeral.
* A YANG data module could be all ephemeral (e.g.
[I-D.ietf-i2rs-rib-data-model]) with no directly associated
configuration models,
* A YANG model could be all ephemeral but associated with a
configuration model
* or a single data node or data tree could be made ephemeral.
Hares & Dass Expires May 19, 2017 [Page 17]
Internet-Draft I2RS Protocol Yang November 2016
6. The management protocol (NETCONF/RESTCONF) needs to signal which
poritons of a data model(node, tree, or data model) are ephemeral
in the module library [RFC7895].
5.3. I2RS Agent Caching of Ephemeral Data
The multiple control-plane datastore model
[I-D.nmdsdt-netmod-revised-datastores] architecture allows multiple
datastores which could allow an implementation of caching of
ephemeral data in the I2RS Agent by having a main and a backup I2RS
agent. Early implementations should at least support the single
ephemeral data model, but MAY support the multiple datastore mode.
It is important that these early implementations provide feedback for
standardization on the following:
the policy knobs needed to make single ephemeral control planes
datastores function,
the policy knobs neeed to make multiple ephemeral control plane
datastores which support caching work.
5.4. Massive Amounts of Configuration Data
Large amounts of data can flow from the I2RS agent to the I2RS
client, or from the I2RS client to the I2RS Agent. The I2RS client
may set or query ephemeral configuration in the routing system via
the I2RS agent and receive operational state, notifications, or
logging from the I2RS Agent on behalf of the I2RS routing system.
I2RS Clients can send large amount of ephemeral configuration data to
the I2RS Agent. The writes may be done via NETCONF (<edit-config> or
an rpc function), or via RESTCONF (PUT, PATCH, POST). Reads can be
done via NETCONF <get-config> or RESTCONF GET or query.
The I2RS RIB Data Model [I-D.ietf-i2rs-rib-data-model] also supports
the use of rpc to add/delete RIBs, add/delete/update routes, and add/
delete nexthops. If the I2RS client does a small to medium number of
writes to the I2RS ephemeral state in the I2RS Agent in a routing
system, the full validation that NETCONF or RESTCONF does will be
able to be done without any reduction in speed to the I2RS high-
performance system. For example, if the I2RS RIB Data Model has adds
a 1000 routes, the I2RS RIB use of rpc to add/delete/update routes
should be able to provide a high-performance system. Alternatively
the NETCONF <edit-config> could update these 1000 routes with a
write, or the RESTCONF POST, PUT or PATCH should be able to add the
1000 routes.
If a large number of ephemeral routes or filters are written (updates
or new) by the I2RS Client to the ephemeral state in the I2RS agent,
Hares & Dass Expires May 19, 2017 [Page 18]
Internet-Draft I2RS Protocol Yang November 2016
one of the key issues for a high performance interface is the time it
takes to validate routes. Due to this concern, the I2RS architecture
was design to allow less than the full NETCONF or RESTCONF
validation. The concept is that the I2RS routes would be validated
within the I2RS client and sent via a 99.999% reliable connection.
In this scenario, the I2RS Agent would trust the validation that the
I2RS Client did, and the communication of the route additions via the
network connection.
An experiment regarding this has been done with the ODL code base
update of ephemeral routes, but additional experimentation needs to
be done prior to finalizing this design. Section 3.4.2 reviews how
this process might be done, but many open issues exist in
implementing this "low-validation" interface. Without additional
experimentation and prototype code, this type of "low-validation",
5.5. Write Error handling
This section reviews I2RS normal error handling and error handling
for rpc with no validation checks.
5.5.1. Normal validation checks
An I2RS agent validates an I2RS client's information by examining the
following:
o message syntax validation,
o syntax validation for nodes of data model,
o referential checks (leafref checks MUST clauses, and instance
indentifier),
o checks groups of data within a data model or groups of data across
data models,
o write access to data,
o if write access and values already exist, if I2RS client write
access is higher than existing priority.
5.5.1.1. Reduced Validation (Experimental)
Can the I2RS protocol allow for reduced error checking? The need for
speed in the I2RS protocol insertions in to the I2RS RIB suggest that
it is worth experimenting for reduced validation in order to obtain
high levels of throughput. If NETCONF or RESTCONf streams pre-
Hares & Dass Expires May 19, 2017 [Page 19]
Internet-Draft I2RS Protocol Yang November 2016
checked routes to the datastore, what happens? Implementation
experience is needed to determine the feasibility of this approach.
This feature may require a operator-applied policy knob swith a "no
validation" feature
o operator-applied policy knob enabling this feature;
o rpc in a data model with the yang "ephemeral-validation no-check;"
5.6. IPFIX for traffic monitoring
Due to the potentially large data flow the traffic measurment
statistics generate, these statistics are best handled by publication
techniques within NETCONF or a separate protocol such as IPFIX. In
the future version of the I2RS protocol may desire to support a data
stream outbound from the I2RS Agent to an I2RS client via the IPFIX
protocol.
5.7. Binary encoding of RESTCONF/NETCONF
The binary encoding of JSON or XML encodnig in RESTCONF or NETCONF
may provide a better throughput. Research needs to be done on what
is the appropriate binary encoding.
5.8. Ephemeral state in DDoS environments
I2RS ephemeral state may operate in places where there is a DDoS
attacks where the network devices are attacked. Is one attack plane
the ability to remove all tracing if the I2RS reboots an attack
vector?
6. IANA Considerations
This is a protocol strawman - nothing is going to IANA.
7. Security Considerations
The security requirements for the I2RS protocol are covered in
[I-D.ietf-i2rs-protocol-security-requirements]. The security
environment the I2RS protocol is covered in
[I-D.ietf-i2rs-security-environment-reqs]. Any person implementing
or deploying the I2RS protocol should consider both security
requirements.
Hares & Dass Expires May 19, 2017 [Page 20]
Internet-Draft I2RS Protocol Yang November 2016
8. Acknowledgements
TBD
9. References
9.1. Normative References:
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic
Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107,
June 2005, <http://www.rfc-editor.org/info/rfc4107>.
[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
RFC 4960, DOI 10.17487/RFC4960, September 2007,
<http://www.rfc-editor.org/info/rfc4960>.
[RFC5339] Le Roux, JL., Ed. and D. Papadimitriou, Ed., "Evaluation
of Existing GMPLS Protocols against Multi-Layer and Multi-
Region Networks (MLN/MRN)", RFC 5339,
DOI 10.17487/RFC5339, September 2008,
<http://www.rfc-editor.org/info/rfc5339>.
[RFC5424] Gerhards, R., "The Syslog Protocol", RFC 5424,
DOI 10.17487/RFC5424, March 2009,
<http://www.rfc-editor.org/info/rfc5424>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<http://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<http://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<http://www.rfc-editor.org/info/rfc6242>.
[RFC6244] Shafer, P., "An Architecture for Network Management Using
NETCONF and YANG", RFC 6244, DOI 10.17487/RFC6244, June
2011, <http://www.rfc-editor.org/info/rfc6244>.
Hares & Dass Expires May 19, 2017 [Page 21]
Internet-Draft I2RS Protocol Yang November 2016
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
DOI 10.17487/RFC6536, March 2012,
<http://www.rfc-editor.org/info/rfc6536>.
[RFC7158] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", RFC 7158, DOI 10.17487/RFC7158, March
2014, <http://www.rfc-editor.org/info/rfc7158>.
[RFC7589] Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the
NETCONF Protocol over Transport Layer Security (TLS) with
Mutual X.509 Authentication", RFC 7589,
DOI 10.17487/RFC7589, June 2015,
<http://www.rfc-editor.org/info/rfc7589>.
[RFC7803] Leiba, B., "Changing the Registration Policy for the
NETCONF Capability URNs Registry", BCP 203, RFC 7803,
DOI 10.17487/RFC7803, February 2016,
<http://www.rfc-editor.org/info/rfc7803>.
[RFC7895] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Module
Library", RFC 7895, DOI 10.17487/RFC7895, June 2016,
<http://www.rfc-editor.org/info/rfc7895>.
[RFC7920] Atlas, A., Ed., Nadeau, T., Ed., and D. Ward, "Problem
Statement for the Interface to the Routing System",
RFC 7920, DOI 10.17487/RFC7920, June 2016,
<http://www.rfc-editor.org/info/rfc7920>.
[RFC7921] Atlas, A., Halpern, J., Hares, S., Ward, D., and T.
Nadeau, "An Architecture for the Interface to the Routing
System", RFC 7921, DOI 10.17487/RFC7921, June 2016,
<http://www.rfc-editor.org/info/rfc7921>.
[RFC7922] Clarke, J., Salgueiro, G., and C. Pignataro, "Interface to
the Routing System (I2RS) Traceability: Framework and
Information Model", RFC 7922, DOI 10.17487/RFC7922, June
2016, <http://www.rfc-editor.org/info/rfc7922>.
[RFC7923] Voit, E., Clemm, A., and A. Gonzalez Prieto, "Requirements
for Subscription to YANG Datastores", RFC 7923,
DOI 10.17487/RFC7923, June 2016,
<http://www.rfc-editor.org/info/rfc7923>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<http://www.rfc-editor.org/info/rfc7950>.
Hares & Dass Expires May 19, 2017 [Page 22]
Internet-Draft I2RS Protocol Yang November 2016
[RFC7952] Lhotka, L., "Defining and Using Metadata with YANG",
RFC 7952, DOI 10.17487/RFC7952, August 2016,
<http://www.rfc-editor.org/info/rfc7952>.
[RFC7958] Abley, J., Schlyter, J., Bailey, G., and P. Hoffman,
"DNSSEC Trust Anchor Publication for the Root Zone",
RFC 7958, DOI 10.17487/RFC7958, August 2016,
<http://www.rfc-editor.org/info/rfc7958>.
9.2. Informative References
[I-D.ietf-i2rs-ephemeral-state]
Haas, J. and S. Hares, "I2RS Ephemeral State
Requirements", draft-ietf-i2rs-ephemeral-state-22 (work in
progress), November 2016.
[I-D.ietf-i2rs-protocol-security-requirements]
Hares, S., Migault, D., and J. Halpern, "I2RS Security
Related Requirements", draft-ietf-i2rs-protocol-security-
requirements-17 (work in progress), September 2016.
[I-D.ietf-i2rs-rib-data-model]
Wang, L., Ananthakrishnan, H., Chen, M.,
amit.dass@ericsson.com, a., Kini, S., and N. Bahadur, "A
YANG Data Model for Routing Information Base (RIB)",
draft-ietf-i2rs-rib-data-model-06 (work in progress), July
2016.
[I-D.ietf-i2rs-rib-info-model]
Bahadur, N., Kini, S., and J. Medved, "Routing Information
Base Info Model", draft-ietf-i2rs-rib-info-model-09 (work
in progress), July 2016.
[I-D.ietf-i2rs-security-environment-reqs]
Migault, D., Halpern, J., and S. Hares, "I2RS Environment
Security Requirements", draft-ietf-i2rs-security-
environment-reqs-01 (work in progress), April 2016.
[I-D.ietf-i2rs-yang-l3-topology]
Clemm, A., Medved, J., Varga, R., Tkacik, T., Liu, X.,
Bryskin, I., Guo, A., Ananthakrishnan, H., Bahadur, N.,
and V. Beeram, "A YANG Data Model for Layer 3 Topologies",
draft-ietf-i2rs-yang-l3-topology-04 (work in progress),
September 2016.
Hares & Dass Expires May 19, 2017 [Page 23]
Internet-Draft I2RS Protocol Yang November 2016
[I-D.ietf-netconf-call-home]
Watsen, K., "NETCONF Call Home and RESTCONF Call Home",
draft-ietf-netconf-call-home-17 (work in progress),
December 2015.
[I-D.ietf-netconf-keystore]
Watsen, K. and G. Wu, "Keystore Model", draft-ietf-
netconf-keystore-00 (work in progress), October 2016.
[I-D.ietf-netconf-netconf-event-notifications]
Prieto, A., Clemm, A., Voit, E., Nilsen-Nygaard, E.,
Tripathy, A., Chisholm, S., and H. Trevino, "NETCONF
Support for Event Notifications", draft-ietf-netconf-
netconf-event-notifications-01 (work in progress), October
2016.
[I-D.ietf-netconf-restconf]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", draft-ietf-netconf-restconf-18 (work in
progress), October 2016.
[I-D.ietf-netconf-rfc5277bis]
Clemm, A., Prieto, A., Voit, E., Nilsen-Nygaard, E.,
Tripathy, A., Chisholm, S., and H. Trevino, "Subscribing
to Event Notifications", draft-ietf-netconf-rfc5277bis-01
(work in progress), October 2016.
[I-D.ietf-netconf-tls-client-server]
Watsen, K., "TLS Client and Server Models", draft-ietf-
netconf-tls-client-server-01 (work in progress), November
2016.
[I-D.ietf-netconf-yang-patch]
Bierman, A., Bjorklund, M., and K. Watsen, "YANG Patch
Media Type", draft-ietf-netconf-yang-patch-13 (work in
progress), November 2016.
[I-D.ietf-netconf-yang-push]
Clemm, A., Voit, E., Prieto, A., Tripathy, A., Nilsen-
Nygaard, E., Bierman, A., and B. Lengyel, "Subscribing to
YANG datastore push updates", draft-ietf-netconf-yang-
push-04 (work in progress), October 2016.
[I-D.ietf-netconf-zerotouch]
Watsen, K. and M. Abrahamsson, "Zero Touch Provisioning
for NETCONF or RESTCONF based Management", draft-ietf-
netconf-zerotouch-11 (work in progress), October 2016.
Hares & Dass Expires May 19, 2017 [Page 24]
Internet-Draft I2RS Protocol Yang November 2016
[I-D.ietf-netmod-schema-mount]
Bjorklund, M. and L. Lhotka, "YANG Schema Mount", draft-
ietf-netmod-schema-mount-03 (work in progress), October
2016.
[I-D.ietf-netmod-syslog-model]
Wildes, C. and K. Koushik, "A YANG Data Model for Syslog
Configuration", draft-ietf-netmod-syslog-model-11 (work in
progress), November 2016.
[I-D.nmdsdt-netmod-revised-datastores]
Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "A Revised Conceptual Model for YANG
Datastores", draft-nmdsdt-netmod-revised-datastores-00
(work in progress), October 2016.
Authors' Addresses
Susan Hares
Huawei
Saline
US
Email: shares@ndzh.com
Amit Daas
Ericsson
Email: amit.dass@ericsson.com
Hares & Dass Expires May 19, 2017 [Page 25]
