Network Working Group A. Lindem
Internet-Draft Cisco
Intended status: Informational L. Berger, Ed.
Expires: March 22, 2016 LabN
D. Bogdanovic
C. Hopps
Deutsche Telekom
September 21, 2015
Network Device YANG Organizational Model
draft-rtgyangdt-rtgwg-device-model-01
Abstract
This document presents an approach for organizing YANG models in a
comprehensive structure that defines how individual models may be
composed to configure and operate network infrastructure and
services. The structure is itself represented as a YANG model,
with all of the related component models logically
organized in a way that is operationally intuitive. This document is
derived from work submitted to the IETF by members of the informal
OpenConfig working group of network operators and is a product of the
Routing Area YANG Architecture design team.
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
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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 September 10, 2015.
Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
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(http://trustee.ietf.org/license-info) in effect on the date of
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described in the Simplified BSD License.
Contents
1. Introduction ........................................... 3
1.1. Status of Work and Open Issues ......................... 3
2. Model Overview ......................................... 5
2.1. Interface Model Components ............................. 6
2.2. Logical Network Elements ............................... 7
2.2.1. System Management ..................................... 8
2.2.2. Network Instances ..................................... 9
2.2.2.1. OAM Protocols ........................................ 10
2.2.2.2. Network Instance Policy .............................. 11
2.2.2.3. Control Plane Protocols .............................. 11
2.2.2.4. RIBs ................................................. 12
2.2.2.5. MPLS ................................................. 12
2.2.2.6. Networking Services .................................. 12
2.3. Device View vs Logical Network Element (LNE)
View Management ................................. 13
3. Populating the structural model ....................... 14
3.1. Constructing the device model ......................... 14
3.2. "Pull" approach for model composition ................. 15
3.3. "Push" approach for model composition ................. 15
4. Security Considerations ............................... 16
5. IANA Considerations ................................... 16
6. YANG module ........................................... 16
6.1. Model structure ....................................... 16
7. References ............................................ 30
7.1. Normative references .................................. 30
7.2. Informative references ................................ 31
Acknowledgments ....................................... 32
Contributors .......................................... 32
Authors' Addresses ................................... 33
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1. Introduction
"Operational Structure and Organization of YANG Models" [OC-STRUCT],
highlights the value of organizing individual, self-standing YANG
[RFC6020] models into a more comprehensive structure. This
document builds on that work and presents a derivative structure for
use in representing the networking infrastructure aspects of physical
and virtual devices. While [OC-STRUCT] and earlier versions of this
document presented a single device-centric model root, this document
no longer contains this element.
This document aims to provide an extensible structure that can be
used to tie together other models. It allows for existing, emerging,
and future models. The overall structure can be constructed using
YANG augmentation and imports.
This document was motivated by, and derived from, [OC-STRUCT]. The
requirements from that document have been combined with the
requirements from "Consistent Modeling of Operational State Data in
YANG", [OC-OPSTATE], into "NETMOD Operational State Requirements",
[NETMOD-OPSTATE]. This document is aimed at the requirement
related to a common model-structure, currently Requirement 7, and
also aims to provide a modeling base for Operational State
representation.
The approach taken in this (and the original) document is to organize
the models describing various aspects of network infrastructure,
focusing on devices, their subsystems, and relevant protocols
operating at the link and network layers. The proposal does not
consider a common model for higher level network services, nor does
it specify details of how hardware-related data should be organized.
We focus on the set of models that are commonly used by network
operators, and suggest a corresponding organization.
A significant portion of the text and model contained in this
document was taken from the -00 of [OC-STRUCT].
1.1. Status of Work and Open Issues
This version of the document and structure are a product of the
Routing Area YANG Architecture design team and is very much a work in
progress rather than a final proposal. Recent discussions have been
quite focused on the single device root, /device, that was in the -00
version of this document and [OC-STRUCT]. Secondary discussions have
focused on representation of logical network elements. Disagreement
and open issues remain, even within the design team. Major open
issues are as follows:
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1. The structure related to L2VPNs, Ethernet services, and virtual
switching instances has not yet received sufficient discussion
and is likely to change.
2. Additional discussion and text is need to ensure that the
interpretation of different policy containers is clear.
3. Configuration information related to network-instance
interconnection (over a "core" network) is currently commingled
with configuration related to operation within the instance.
4. The representation of operational state is currently missing. The
model will be updated once the "opstate" requirements are
addressed.
5. Interface logical network element id and logical networking
instance name augmentations are currently defined within the
context of network-device. It may clearer to define these each
in their own modules.
6. There is a proposal on the table to support logical network
elements using an enhanced version of [NETMOD-MOUNT]. The authors
and design team are open to this proposal and are interested in
discussing this option as specific details are available.
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2. Module Overview
In this document, we consider network devices that support protocols
and functions defined within the IETF Routing Area, e.g, routers,
firewalls and hosts. Such devices may be physical or virtual, e.g., a
classic router with custom hardware or one residing within a
server-based virtual machine implementing a virtual network function
(VNF). Each device may sub-divide their resources into logical
network elements (LNEs) each of which provides a managed logical
device. Examples of vendor terminology for an LNE include logical
system or router, and virtual switch, chassis, or fabric. Each LNE
may also support virtual routing and forwarding (VRF) and virtual
switching instance (VSI) functions, which are referred to below as a
networking instances (NIs). This breakdown is represented in
Figure 1.
A model for LNEs is described in Section 2.2 and the sub-model for
networking instances is covered in Section 2.2.2.
,''''''''''''''''''''''''''''''''''''''''''''''`.
| Network Device (Physical or Virtual) |
| ..................... ..................... |
| : Logical Network : : Logical Network : |
| : Element : : Element : |
| :+-----+-----+-----+: :+-----+-----+-----+: |
| :| Net | Net | Net |: :| Net | Net | Net |: |
| :|Inst.|Inst.|Inst.|: :|Inst.|Inst.|Inst.|: |
| :+-----+-----+-----+: :+-----+-----+-----+: |
| : | | | | | | : : | | | | | | : |
| :..|.|...|.|...|.|..: :..|.|...|.|...|.|..: |
| | | | | | | | | | | | | |
`'''|'|'''|'|'''|'|'''''''''|'|'''|'|'''|'|'''''
| | | | | | | | | | | |
Interfaces Interfaces
Figure 1: Module Element Relationships
The presented module can itself be thought of as a "meta-model" as it
describes the relationships between individual models. We choose to
represent it also as a simple YANG module consisting of models, lists
and containers to serve as anchor points for the corresponding
individual models.
The module does not follow the hierarchy of any particular
implementation, and hence is vendor-neutral. Nevertheless, the
structure should be familiar to network operators and also readily
mapped to vendor implementations. The overall structure is:
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module: network-device
+--rw info
| +--rw device-type? enumeration
+--rw hardware
+--rw qos
+--rw logical-network-elements
| ...
augment /if:interfaces/if:interface:
...
The top level models generally represent resources that are
associated with a device that can themselves be assigned to LNEs.
Notably, the existing Interface Management model [RFC7223] is also
included at the top level, although it is augmented to allow for
LNEs. An info section is included for basic device information such
as its type (e.g., physical or virtual), vendor, model, etc. The
hardware section is a placeholder for device-specific configuration
and operational state data. For example, a common structure for the
hardware model might include chassis, line cards, and ports, but we
leave this unspecified. The Quality of Service (qos) section is a
placeholder for device-wide configuration and operational state data
which relates to the treatment of traffic across the device.
2.1. Interface Model Components
Interfaces are a crucial part of any network device's configuration
and operational state. They generally include a combination of raw
physical interfaces, link-layer interfaces, addressing configuration,
and logical interfaces that may not be tied to any physical
interface. Several system services, and layer 2 and layer 3
protocols may also associate configuration or operational state data
with different types of interfaces (these relationships are not shown
for simplicity).
This document augments the existing Interface Management model
[RFC7223] in two ways. The first is add an identifier which is
used on physical interface types to identify an associated LNE. The
second is to add a name which is used on sub-interface types to
identify an associated networking instance. Similarly, this name
is also added for IPv4 and IPv6 types, as defined in [RFC7277].
The interface related definitions are as follows:
augment /if:interfaces/if:interface:
+--rw bind-network-element-id? uint8
augment /if:interfaces/if:interface:
+--rw bind-networking-instance-name? string
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augment /if:interfaces/if:interface/ip:ipv4:
+--rw bind-networking-instance-name? string
augment /if:interfaces/if:interface/ip:ipv6:
+--rw bind-networking-instance-name? string
The following is an example of envisioned usage. The interfaces
container includes a number of commonly used components as examples:
+--rw interfaces
| +--rw interface* [name]
| +--rw name string
| +--rw bind-network-element-id? uint8
| +--rw ethernet
| | +--rw bind-networking-instance-name? string
| | +--rw aggregates
| | +--rw rstp
| | +--rw lldp
| | +--rw ptp
| +--rw vlans
| +--rw tunnels
| +--rw ipv4
| | +--rw bind-networking-instance-name? string
| | +--rw arp
| | +--rw icmp
| | +--rw vrrp
| | +--rw dhcp-client
| +--rw ipv6
| +--rw bind-networking-instance-name? string
| +--rw vrrp
| +--rw icmpv6
| +--rw nd
| +--rw dhcpv6-client
The bind-networking-instance-name leaf is an explicit and notable
addition. The [RFC7223] defined interface model is structured to
include all interfaces in a flat list, without regard to logical or
virtual instances (e.g., VRFs) supported on the device. The
bind-networking-instance-name leaf provides the association between
an interface and its associated networking instance (e.g., VRF or
VSI).
2.2. Logical Network Elements
Logical network elements represent the capability on some devices to
partition resources into independent logical routers and/or switches.
Device support for multiple logical network elements is
implementation specific. Systems without such capabilities will have
just a single container. In physical devices, some hardware features
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are shared across partitions, but control plane (e.g., routing)
protocol instances, tables, and configuration are managed separately.
For example, in virtual routers or VNFs, this may correspond to
establishing multiple logical instances using a single software
installation. The model supports configuration of multiple instances
on a single device by creating a list of logical network elements,
each with their own configuration and operational state related to
routing and switching protocols, as shown below:
module: network-device
+--rw logical-network-elements
+--rw logical-network-element* [network-element-id]
+--rw network-element-id uint8
+--rw network-element-name? string
+--rw default-networking-instance-name? string
+--rw system-management
| ...
+--rw ietf-acl
+--rw ietf-key-chain
+--rw networking-instances
| ...
Network-element-id and network-element-name identify the logical
network element.
Default-networking-instance-name identifies the networking instance
to use for system management connectivity. Other instances may
access system management function through appropriate inter-instance
configuration.
2.2.1. System Management
The model supports the potentially independent system management
functions and configuration per logical network element. This
permits, for example, different users to manage either the whole
device or just the associated logical network element. System
management is supported by the system-management container which is
expected to reuse definitions contained in [RFC7317] and is shown
below:
module: network-device
+--rw logical-network-elements
+--rw logical-network-element* [network-element-id]
+--rw system-management
+--rw device-view? boolean
+--rw system-management-global
+--rw system-management-protocol* [type]
+--rw type identityref
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The device-view leaf is used to indicate if the system management
functions associated with the logical network element are restricted
to the logical network element or can manage the whole device. The
leaf may have a fixed value. For example, some implementations may
only support management on a device-wide basis. Additional
information on the implications of this leaf can be found in Section
2.3.
System-management-global is used for configuration information and
state that is independent of a particular management protocol.
System-management-protocol is a list of management protocol specific
elements. The type-specific sub-modules are expected to be defined.
The following is an example of envisioned usage:
module: network-device
+--rw logical-network-elements
+--rw system-management
+--rw device-view? boolean
+--rw system-management-global
| +--rw statistics-collection
| ...
+--rw system-management-protocol* [type]
| +--rw syslog
| +--rw dns
| +--rw ntp
| +--rw ssh
| +--rw tacacs
| +--rw snmp
| +--rw netconf
2.2.2. Network Instances
The network instance container is used to represent virtual routing
and forwarding instances (VRFs) and virtual switching instances
(VSIs), [RFC4026]. VRFs and VSIs are commonly used to isolate
routing and switching domains, for example to create virtual private
networks, each with their own active protocols and routing/switching
policies. The model represents both core/provider and virtual
instances. Network instances reuse and build on [RTG-CFG] and are
shown below:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw networking-instance-name string
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+--rw type? identityref
+--rw enabled? boolean
+--rw router-id? uint32
+--rw description? string
+--rw oam-protocols
| ...
+--rw networking-instance-policy
| ...
+--rw control-plane-protocols
| ...
+--rw ribs
| ...
+--rw mpls
| ...
+--rw networking-services
...
[Editor's note: L2/MAC forwarding table is TBD]
2.2.2.1. OAM Protocols
OAM protocols that may run within the context of a network instance
are grouped. The type identifyref is used to identify the information
and state that may relate to a specific OAM protocol. The defined
structure is as follows:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw oam-protocols
+--rw oam-protocol* [type]
+--rw type identityref
The following is an example of envisioned usage. Examples shown
below include Bi-directional Forwarding Detection (BFD), Ethernet
Connectivity Fault Management (CFM), and Two-Way Active Measurement
Protocol (TWAMP):
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw oam-protocols
+--rw oam-protocol* [type]
+--rw bfd
+--rw cfm
+--rw twamp
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2.2.2.2. Network Instance Policy
Network instance policies are used to control provider instances, VRF
routing policies, and VRF/VSI identifiers. Examples include BGP route
targets (RTs) and route distinguishers (RDs), if the instances is a
core/provider instance, virtual network identifiers(VN-IDs), VPLS
neighbors, etc. The structure is:
The following is an example of envisioned usage:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw networking-instance-policy
(TBD)
2.2.2.3. Control Plane Protocols
Control plane protocols that may run within the context of a network
instance are grouped. Each protocol is expected to have its own
model, which is indicated by the type identityref. Protocol specific
policy is included with the protocol rather than being combined in a
separate generic policy grouping. The rationale behind this is that
this ensures that only protocol relevant policies may be configured.
A reusable or common approach may still be leveraged in creating
these policy groupings, perhaps based on [RTG-POLICY]. The defined
structure is as follows:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw control-plane-protocols
+--rw control-plane-protocol* [type]
+--rw type identityref
+--rw policy
The following is an example of envisioned usage:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw control-plane-protocols
+--rw control-plane-protocol* [type]
+--rw bgp
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+--rw is-is
+--rw ospf
+--rw rsvp
+--rw segment-routing
+--rw ldp
+--rw pim
+--rw igmp
+--rw mld
+--rw static-routes
2.2.2.4. RIBs
Every routing instance manages one or more routing information bases
(RIB). A RIB is a list of routes complemented with administrative
data. RIBs reuse and build on [RTG-CFG] and are shown below:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw ribs
+--rw rib* [name]
+--rw name string
+--rw description? string
+--rw policy
2.2.2.5. MPLS
MPLS data plane related information is grouped together. MPLS
control plane protocols are included above. MPLS may reuse and
build on [OC-MPLS] or other emerging models and is shown below:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw mpls
+--rw global
+--rw label-switched-paths
+--rw constrained-path
+--rw igp-congruent
+--rw static
2.2.2.6. Networking Services
A device may provide services to other devices within the scope of a
networking instance. The type identifyref is used to identify the
service specific configuration and state information. The defined
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structure is as follows:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw networking-services
+--rw networking-service* [type]
+--rw type identityref
The following is an example of envisioned usage: Examples shown below
include a device-based Network Time Protocol (NTP) server, a Domain
Name System (DNS) server, and a Dynamic Host Configuration Protocol
(DHCP) server:
module: network-device
+--rw logical-network-elements
+--rw networking-instances
+--rw networking-instance* [networking-instance-name]
+--rw networking-services
+--rw networking-service* [type]
+--rw ntp-server
+--rw dns-server
+--rw dhcp-server
2.3. Device View vs Logical Network Element (LNE) View Management
[Editor's note: an alternate approach based on a future enhanced
version of [NETMOD-MOUNT] has been proposed and is being
considered. This section would be replaced if such an alternate
approach is followed. ]
On some devices it is possible to limit control and management to a
scoped set of system resources. As stated above in Section 2.2., the
documented approach supports this capability using logical network
elements and the system management device-view leaf.
When the device-view leaf is set to true, information accessible via
a logical network element's system management functions represents
the complete device. This applies to all system management
functions, not just those represented in the YANG model. When
viewing information represented in a YANG model, the device model
will cover the full device and allow management across all logical
network elements.
The case when a logical network element's system management functions
do not have a device wide view is more complex. In this case, there
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are two perspectives: one from functions that are operating within a
context of a logical network element that has a device wide view (or
more simply have a "device view"); and the other from functions that
are operating within the context of a logical network element that
has only a logical network element view (or more simply have an "LNE
view").
From a management function operating with a device view, the
limited logical network element's system management device-view
leaf is simply set to false.
Management functions operating with an LNE view can only see
information (e.g., resources, interfaces, configuration, operational
state, etc.) associated with in the logical network element. When
viewing information represented in a YANG model, a full device model
(as defined in this document) is available from within the view, but
it includes only those elements associated with the LNE. For
information contained with the logical-network-element container
entry, this is the same information as available in a device wide
view. Information outside the logical-network-elements container is
made available within an LNE view as is appropriated based on device
wide configuration. For example, interfaces assigned to the logical
network element can be managed from within the LNE view. Note: some
information that can be modified from a device view may be read-only
from within the LNE view.
Multiple implementation approaches are possible to provide LNE views,
and these are outside the scope of this document.
3. Populating the structural model
The structural model in this document describes how individual YANG
models may be used together to represent the configuration and
operational state for all parts of a physical or virtual device. It
does not, however, document the actual model in its entirety. In
this section, we outline an option for creating the full model and
also describe how it may be used.
3.1. Constructing the device model
One of the challenges in assembling existing YANG models is that they
are generally written with the assumption that each model is at the
root of the configuration or state tree. Combining models then
results in a multi-rooted tree that does not follow any logical
construction and makes it difficult to work with operationally. In
some cases, models explicitly reference other models (e.g., via
augmentation) to define a relationship, but this is the case for only
a few existing models.
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Some examples include the interfaces [RFC7223] and IP management
[RFC7277] models, and proposed IS-IS [RTG-ISIS], OSPF [RTG-OSPF] and
routing configuration [RTG-CFG] models.
3.2. "Pull" approach for model composition
To enable model composition, one possible approach is to avoid using
root-level containers in individual component models. Instead, the
top level container (and all other data definitions) can be enclosed
in a YANG 'grouping' statement so that when the model is imported by
another model, its location in the configuration tree can be
controlled by the importing YANG module with the 'uses' statement.
One advantage of this approach is that the importing module has the
flexibility to readily use the data definitions where the author
deems appropriate.
One obvious drawback is that individual models no longer contain any
of their own data definitions and must be used by a higher-level
model for their data nodes to become active. Some judgment as to
which models are more suited for inclusion in higher level models is
also necessary to decide when the corresponding YANG module should
only contain groupings. Another potential drawback is that this
approach does not define a common structure for models to fit
together, limiting interoperability due to implementations using
different structures. To address this, a top-level standard model
structure could be defined and updated to import new models into the
hierarchy as they are defined.
3.3. "Push" approach for model composition
An alternative approach is to develop a top level model which defines
the overall structure of the models, similar to the structure
described in Section 2. Individual models may augment the top level
model with their data nodes in the appropriate locations. The
drawback is the need for a pre-defined top level model structure. On
the other hand, when this top level model is standardized, it can
become the basis for a vendor-neutral way to manage devices, assuming
that the component models are supported by a given implementation.
One question in both approaches is what the root of the top-level
model should be. In this document we selected to base the model at a
device because this layer should be common across many use cases and
implementations. Starting at a higher layer (e.g., services) makes
defining and agreeing on a common organization more challenging as
discussed in Section 1.1.
Ideally, one could consider a hybrid construction mechanism that
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supports both styles of model composition. For example, a YANG
compiler or preprocessing directive could be used to indicate whether
an individual model should assume it is at the root, or whether it is
meant for inclusion in other higher-level models.
4. Security Considerations
The model structure described in this document does not define actual
configuration and state data, hence it is not directly responsible
for security risks.
However, each of the component models that provide the corresponding
configuration and state data should be considered sensitive from a
security standpoint since they generally manipulate aspects of
network configurations. Each component model should be carefully
evaluated to determine its security risks, along with mitigations to
reduce such risks.
5. IANA Considerations
This YANG model currently uses a temporary ad-hoc namespace. If it
is placed or redirected for the standards track, an appropriate
namespace URI will be registered in the "IETF XML Registry"
[RFC3688]. The YANG structure modules will be registered in the
"YANG Module Names" registry [RFC6020].
6. YANG module
The model structure is described by the YANG module below.
6.1. Model structure
<CODE BEGINS> file "network-device.yang"
module network-device {
yang-version "1";
// namespace
namespace "urn:ietf:params:xml:ns:yang:network-device";
prefix "struct";
// import some basic types
import ietf-interfaces {
prefix if;
}
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import ietf-ip {
prefix ip;
}
// meta
organization "IETF RTG YANG Design Team Collaboration
with OpenConfig";
contact
"Routing Area YANG Architecture Design Team -
<rtg-dt-yang-arch@ietf.org>";
description
"This module describes a model structure for YANG
configuration and operational state data models. Its intent is
to describe how individual device protocol and feature models
fit together and interact.";
revision "2015-09-06" {
description
"IETF Routing YANG Design Team Meta-Model";
reference "TBD";
}
// extension statements
// feature statements
feature bind-network-element-id {
description
"Logical network element ID to which an interface is bound";
}
feature bind-networking-instance-name {
description
"Networking Instance to which an interface instance is bound";
}
// identity statements
identity networking-instance {
description
"Base identity from which identities describing
networking instance types are derived.";
}
identity oam-protocol-type {
description
"Base identity for derivation of OAM protocols";
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}
identity networking-service-type {
description
"Base identity for derivation of networking services";
}
identity ethernet-protocol-type {
description
"Base identity for derivation of ethernet
protocols";
}
identity ipv4-interface-protocol-type {
description
"Base identity for derivation of IPv4 interface
protocols";
}
identity ipv6-interface-protocol-type {
description
"Base identity for derivation of IPv6 interface
protocols";
}
identity mpls-protocol-type {
description
"Base identity for derivation of MPLS protocols";
}
identity control-plane-protocol-type {
description
"Base identity for derivation of control-plane protocols";
}
identity system-management-protocol-type {
description
"Base identity for derivation of system management
protocols";
}
identity oam-service-type {
description
"Base identity for derivation of Operations,
Administration, and Maintenance (OAM) services.";
}
identity aaa-service-type {
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description
"Base identity for derivation of Authentication,
Authorization, and Accounting (AAA) services.";
}
// typedef statements
// grouping statements
grouping interface-ip-common {
description
"interface-specific configuration for IP interfaces, IPv4 and
IPv6";
}
grouping ethernet-protocols {
description
"Grouping for ethernet protocols configured
on an interface";
container ethernet-protocols {
description
"Container for list of ethernet protocols configured
on an interface";
list ethernet-protocol {
key "type";
description
"List of ethernet protocols configured
on an interface";
leaf type {
type identityref {
base ethernet-protocol-type;
}
mandatory true;
description
"Aggregates, RSTP, LLDP, PTP, etc.";
}
}
}
}
grouping ipv4-interface-protocols {
container ipv4-interface-protocols {
list ipv4-interface-protocol {
key "type";
leaf type {
type identityref {
base ipv4-interface-protocol-type;
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}
mandatory true;
description
"ARP, ICMP, VRRP, DHCP Client, etc.";
}
description
"List of IPv4 protocols configured
on an interface";
}
description
"Container for list of IPv4 protocols configured
on an interface";
}
description
"Grouping for IPv4 protocols configured on an interface";
}
grouping ipv6-interface-protocols {
description
"Grouping for IPv6 protocols configured on
an interface.";
container ipv6-interface-protocols {
description
"Container for list of IPv6 protocols configured
on an interface.";
list ipv6-interface-protocol {
key "type";
description
"List of IPv6 protocols configured
on an interface";
leaf type {
type identityref {
base ipv6-interface-protocol-type;
}
mandatory true;
description
"ND, ICMPv6, VRRP, DHCPv6 Client, etc.";
}
}
}
}
grouping router-id {
description
"This grouping provides router ID.";
leaf router-id {
type uint32; // yang:dotted-quad
description
"A 32-bit number in the form of a dotted quad that is
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used by some routing protocols identifying a router.";
reference
"RFC 2328: OSPF Version 2.";
}
}
grouping oam-protocols {
container oam-protocols {
list oam-protocol {
key "type";
leaf type {
type identityref {
base oam-protocol-type;
}
mandatory true;
description
"The Operations, Administration, and
Maintenance (OAM) protocol type, e.g., BFD,
TWAMP, CFM, etc.";
}
description
"List of OAM protocols configured for a
networking instance.";
}
description
"Container for list of OAM protocols configured for a
networking instance.";
}
description
"Grouping for OAM protocols configured for a
networking instance.";
}
grouping mpls {
description
"Grouping for MPLS and TE configuration configured for
a networking-instance.";
container mpls {
description
"Container for MPLS and TE configuration for a
networking-instance.";
container global {
description "Global MPLS configuration";
}
list mpls-protocol {
key "type";
description
"List of MPLS protocols configured for a
networking instance.";
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leaf type {
type identityref {
base mpls-protocol-type;
}
mandatory true;
description
"MPLS and Traffic Engineering protocol type,
MPLS static, LDP, RSVP TE, etc.";
}
}
}
}
grouping networking-instance-policy {
description
"Networking instance policies such as route
distinguisher, route targets, VPLS ID and neighbor,
Ethernet ID, etc. ";
reference
"RFC 4364 - BGP/MPLS Virtual Private Networks (VPNs)
RFC 6074 - Provisioning, Auto-Discovery, and Signaling
in Layer 2 Virtual Private Networks (L2VPNs)
RFC 7432 - BGP MPLS-Based Ethernet VPN";
container networking-instance-policy {
description "Networking Instance Policy -- details TBD";
}
}
grouping control-plane-protocols {
description
"Grouping for control plane protocols configured for
a networking-instance";
container control-plane-protocols {
description
"Container for control plane protocols configured for
a networking instance.";
list control-plane-protocol {
key "type";
description
"List of control plane protocols configured for
a networking instance.";
leaf type {
type identityref {
base control-plane-protocol-type;
}
mandatory true;
description
"The control plane protocol type, e.g., BGP,
OSPF IS-IS, etc";
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}
container policy {
description
"Protocol specific policy,
reusing [RTG-POLICY]";
}
}
}
}
grouping ribs {
description
"Routing Information Bases (RIBs) supported by a
networking-instance";
container ribs {
description
"RIBs supported by a networking-instance";
list rib {
key "name";
min-elements "1";
description
"Each entry represents a RIB identified by the
'name' key. All routes in a RIB must belong to the
same address family.
For each routing instance, an implementation should
provide one system-controlled default RIB for each
supported address family.";
leaf name {
type string;
description
"The name of the RIB.";
}
reference "draft-ietf-netmod-routing-cfg";
leaf description {
type string;
description
"Description of the RIB";
}
// Note that there is no list of interfaces within
container policy {
description "Policy specific to RIB";
}
}
}
}
grouping networking-services {
description
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"Grouping for networking-services configured for
a networking-instance.";
container networking-services {
description
"Container for lst of networking services configured
for a networking instance.";
list networking-service {
key "type";
description
"List of networking services configured for a
networking instance.";
leaf type {
type identityref {
base networking-service-type;
}
mandatory true;
description
"The networking services type supported within
a networking instance, e.g., NTP server, DNS
server, DHCP server, etc.";
}
}
}
}
grouping oam-services {
description "containers for features related to operations,
administration, and maintenance (OAM).";
container oam-services {
description "Commonly use OAM functions on devices";
list oam-service {
key "type";
description
"List of OAM services configured for a
logical network element.";
leaf type {
type identityref {
base oam-service-type;
}
mandatory true;
description
"The OAM services type supported within
a logical networking element, e.g., SNMP.";
}
}
}
}
grouping system-services {
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description "Containers for system service models.";
uses oam-services;
}
grouping system-aaa {
description "AAA-related services";
container aaa {
description
"Authentication, Authorization, and Accounting (AAA).";
list aaa-service {
key "type";
description
"List of AAA services configured for a
logical network element.";
leaf type {
type identityref {
base aaa-service-type;
}
mandatory true;
description
"The AAA services type supported within
a logical networking element, e.g., RADIUS.";
}
}
}
}
grouping system-management {
description "System management for device or logical network
element";
container system-management {
description "System management for device or logical
network element";
leaf device-view {
type boolean;
default "true";
description "Flag indicating whether or not the
logical
network element is able to view and manage
the entire device";
}
container system-management-global {
description "System management - logical device
management with reuse of RFC 7317";
}
list system-management-protocol {
key "type";
leaf type {
type identityref {
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base system-management-protocol-type;
}
mandatory true;
description
"NTP, DNS, Syslog, ssh, TACAC+, NETCONF, etc.";
}
description "List of system management protocol
configured for a logical networking
element.";
}
}
}
grouping ietf-acl {
description "Packet Access Control Lists (ACLs) as specified
in draft-ietf-netmod-acl-model";
container ietf-acl {
description "ACLs and packet forwarding rules";
}
}
grouping ietf-key-chain {
description "Key chains as specified in
draft-acee-rtgwg-yang-key-chain;";
container ietf-key-chain {
description "Key chains";
}
}
// top level device definition statements
container info {
description
"Base system information.
This container is for base system information, including
device type (e.g., physical or virtual), model, serial no.,
location, etc.";
leaf device-type {
//TODO: consider changing to an identity if finer grained
// device type classification is envisioned
type enumeration {
enum PHYSICAL {
description "physical or hardware device";
}
enum VIRTUAL {
description "virtual or software device";
}
}
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description
"Type of the device, e.g., physical or virtual. This node
may be used to activate other containers in the model";
}
}
container hardware {
description
"Hardware / vendor -specific data relevant to the platform.
This container is an anchor point for platform-specific
configuration and operational state data. It may be further
organized into chassis, line cards, ports, etc. It is
expected that vendor or platform-specific augmentations
would be used to populate this part of the device model";
}
container qos {
description "QoS features, for example policing, shaping, etc.";
}
container logical-network-elements {
description "Network devices may support multiple logical
network instances";
list logical-network-element {
key network-element-id;
description "List of logical network elements";
leaf network-element-id {
type uint8; // expect a small number of logical routers
description "Device-wide unique identifier for the
logical network element";
}
leaf network-element-name {
type string;
description "Descriptive name for the logical network
element";
}
leaf default-networking-instance-name {
type string;
description "Specification of the networking instance to
use for management connectivity";
}
uses system-management;
uses ietf-acl;
uses ietf-key-chain;
container networking-instances {
description "Networking instances each of which have
an independent IP/IPv6 addressing space
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and protocol instantiations. For layer 3,
this consistent with the routing-instance
definition in ietf-routing";
reference "draft-ietf-netmod-routing-cfg";
list networking-instance {
key networking-instance-name;
description "List of networking-instances";
leaf networking-instance-name {
type string;
description "logical network element scoped
identifier for the networking
instance";
}
leaf type {
type identityref {
base networking-instance;
}
description
"The networking instance type -- details TBD
Likely types include core, L3-VRF, VPLS,
L2-cross-connect, L2-VSI, etc.";
}
leaf enabled {
type boolean;
default "true";
description
"Flag indicating whether or not the networking
instance is enabled.";
}
uses router-id {
description
"Router ID for networking instances";
}
leaf description {
type string;
description
"Description of the networking instance
and its intended purpose";
}
// Note that there is no list of interfaces within
// the networking-instance
uses oam-protocols;
uses networking-instance-policy;
uses control-plane-protocols;
uses ribs;
uses mpls;
uses networking-services;
}
}
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}
}
// augment statements
augment "/if:interfaces/if:interface" {
description
"Add a node for the identification of the logical network
element associated with an interface. Applies to interfaces
that can be assigned on a per logical network element basis.
A <TBD> error is returned when the interface type cannot be
assigned.";
leaf bind-network-element-id {
type uint8;
description
"Logical network element ID to which interface is bound";
}
}
augment "/if:interfaces/if:interface" {
description
"Add a node for the identification of the logical networking
instance (which is within the interface's identified logical
network element) associated with the IP information
configured on an interface";
leaf bind-networking-instance-name {
type string;
description
"Networking Instance to which an interface is bound";
}
}
augment "/if:interfaces/if:interface/ip:ipv4" {
description
"Add a node for the identification of the logical networking
instance (which is within the interface's identified logical
network element) associated with the IP information
configured on an interface";
leaf bind-networking-instance-name {
type string;
description
"Networking Instance to which IPv4 interface is bound";
}
}
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augment "/if:interfaces/if:interface/ip:ipv6" {
description
"Add a node for the identification of the logical networking
instance (which is within the interface's identified logical
network element) associated with the IP information
configured on an interface";
leaf bind-networking-instance-name {
type string;
description
"Networking Instance to which IPv6 interface is bound";
}
}
// rpc statements
// notification statements
}
<CODE ENDS>
7. References
7.1. Normative references
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the
Network Configuration Protocol (NETCONF)", RFC 6020,
October 2014.
[RFC7223] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 7223, May 2014.
[RFC7277] Bjorklund, M., "A YANG Data Model for IP Management", RFC
7277, June 2014.
[RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for
System Management", RFC 7317, August 2014.
[RFC3688] Mealling, M., "The IETF XML Registry", RFC 3688, January
2004.
7.2. Informative references
[NETMOD-MOUNT] Clemm, A., Medved, J., Voit, E., "Mounting
YANG-Defined Information from Remote Datastores",
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work in progress, draft-clemm-netmod-mount (work in
progress).
[NETMOD-OPSTATE] Watsen, K., Nadeau, T., "NETMOD Operational State
Requirements", work in progress,
draft-chairs-netmod-opstate-reqs (work in
progress).
[OC-MPLS] George, J., Fang, L., Osborne, E., Shakir, R., "MPLS TE
Model for Service Provider Networks",
draft-openconfig-mpls-consolidated-model (work in
progress).
[OC-OPSTATE] Shakir, R., Shaikh, A., and M. Hines, "Consistent
Modeling of Operational State Data in YANG",
draft-openconfig-netmod-opstate (work in progress).
[OC-STRUCT] Shaikh, A., Shakir, R., D'Souza, K., Fang, L.,
"Operational Structure and Organization of YANG Models",
draft-openconfig-netmod-model-structure (work in
progress).
[RFC4026] Andersson, L., Madsen, T., "Provider Provisioned Virtual
Private Network (VPN) Terminology", RFC 4026, March 2005.
[RFC7277] Bjorklund, M., "A YANG Data Model for IP Management",
RFC 7277, June 2014.
[RTG-CFG] Lhotka, L., "A YANG Data Model for Routing Management",
draft-ietf-netmod-routing-cfg (work in progress).
[RTG-POLICY]
Shaikh, A., Shakir, R., D'Souza, K., and C. Chase,
"Routing Policy Configuration Model for Service Provider
Networks", draft-shaikh-rtgwg-policy-model (work in
progress).
[RTG-OSPF] Yeung, D., Qu, Y., Zhang, J., and D. Bogdanovic, "Yang
Data Model for OSPF Protocol", draft-yeung-netmod-ospf
(work in progress).
[RTG-ISIS] Litkowski, S., Yeung, D., Lindem, A., Zhang, J., and L.
Lhotka, "YANG Data Model for ISIS protocol", draft-ietf-
isis-yang-isis-cfg (work in progress).
Appendix A. Acknowledgments
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This document is derived from
draft-openconfig-netmod-model-structure-00. The Authors of that
document who are not also authors of this document are listed as
Contributors to this work.
The original stated: The authors are grateful for valuable
contributions to this document and the associated models from: Deepak
Bansal, Paul Borman, Chris Chase, Josh George, Marcus Hines, and Jim
Uttaro.
The Routing Area Yang Architecture design team members included Acee
Lindem, Anees Shaikh, Christian Hopps, Dean Bogdanovic, Lou Berger,
Qin Wu, Rob Shakir, Stephane Litkowski, and Yan Gang.
The leafref approach was proposed by Mahesh Jethanandani.
Contributors
Anees Shaikh
Google
1600 Amphitheatre Pkwy
Mountain View, CA 94043
US
Email: aashaikh@google.com
Rob Shakir
BT
pp. C3L, BT Centre
81, Newgate Street
London EC1A 7AJ
UK
Email: rob.shakir@bt.com
URI: http://www.bt.com/
Kevin D'Souza
AT&T
200 S. Laurel Ave
Middletown, NJ
US
Email: kd6913@att.com
Luyuan Fang
Microsoft
205 108th Ave. NE, Suite 400
Bellevue, WA
US
Email: lufang@microsoft.com
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Qin Wu
Email: bill.wu@huawei.com
Stephane Litkowski
Email: stephane.litkowski@orange.com
Yan Gang
Email: yangang@huawei.com
Authors' Addresses
Acee Lindem
Cisco Systems
301 Midenhall Way
Cary, NC 27513
USA
Email: acee@cisco.com
Lou Berger (editor)
LabN Consulting, L.L.C.
Email: lberger@labn.net
Dean Bogdanovic
Email: ivandean@gmail.com
Christian Hopps
Deutsche Telekom
Email: chopps@chopps.org
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