A YANG Data Model for Layer 2 Network TopologiesHuaweiNo. 156 Beiqing Rd.Huawei CampusBeijing100095Chinajie.dong@huawei.comHuaweiNo. 156 Beiqing Rd.Huawei CampusBeijing100095Chinaweixiugang@huawei.comHuawei101 Software AvenueYuhua DistrictNanjing210012Chinabill.wu@huawei.comOrangeRennes 35000Francemohamed.boucadair@orange.comTecent38 Haidian StYinke BuildingHaidian DistrictBeijing100080Chinaandersliu@tencent.comVxLANVLANQinQProvider Backbone BridgingEthernetVPLSThis document defines a YANG data model for Layer 2 network
topologies. In particular, this data model augments the generic network
and network topology data models with topology
attributes that are specific to Layer 2.Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by
the Internet Engineering Steering Group (IESG). Further
information on Internet Standards is available in Section 2 of
RFC 7841.
Information about the current status of this document, any
errata, and how to provide feedback on it may be obtained at
.
Copyright Notice
Copyright (c) 2020 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
() in effect on the date of
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
. Introduction
. Terminology
. Layer 2 Topology Model
. Layer 2 Topology YANG Module
. IANA Considerations
. Security Considerations
. References
. Normative References
. Informative References
. Companion YANG Module for Non-NMDA-Compliant Implementations
. An Example
Acknowledgements
Authors' Addresses
Introduction defines the YANG data models of the abstract (generic) network
and network topology. Such models can be augmented with
technology-specific details to build more specific topology models.This document defines the YANG data model for Layer 2 (L2) network
topologies by augmenting the generic network () and network topology () data models with
L2-specific topology attributes. An
example is provided in .There are multiple applications for such a data model. For example,
within the context of Interface to the Routing System (I2RS), nodes
within the network can use the data model to capture their understanding
of the overall network topology and expose it to a network controller. A
network controller can then use the instantiated topology data to
compare and reconcile its own view of the network topology with that of
the network elements that it controls. Alternatively, nodes within the
network may compare and reconcile this understanding either among
themselves or with the help of a controller. Beyond the network element
and the immediate context of I2RS itself, a network controller might
even use the data model to represent its view of the topology that it
controls and expose it to external applications. Further use cases where
the data model can be applied are described in .This document uses the common YANG types defined in and adopts the Network Management Datastore
Architecture (NMDA) .Terminology
The key words "MUST", "MUST NOT",
"REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT",
"RECOMMENDED", "NOT RECOMMENDED",
"MAY", and "OPTIONAL" in this document are
to be interpreted as described in BCP 14 when, and only when, they appear in all capitals,
as shown here.
The terminology for describing YANG modules is defined in . The meanings of the symbols used in the tree diagram
are defined in .Layer 2 Topology ModelThe Layer 2 network topology YANG module is designed to be generic
and applicable to Layer 2 networks built with different Layer 2
technologies. It can be used to describe both the physical and the
logical (virtual) Layer 2 network topologies.The relationship between the Layer 2 topology module and the generic
network and network topology module is shown in . In
order to represent a Layer 2 network topology, the generic network and
topology models are augmented with L2-specific information, such as
the identifiers, identities (e.g., Provider Backbone Bridging , QinQ , or Virtual eXtensible Local Area Network (VXLAN)
), attributes, and states of the Layer 2
networks, nodes, links, and termination points. Some of the information
may be collected via Link Layer Discovery Protocol (LLDP) or other Layer 2 protocols, and some of them may
be locally configured.Layer 2 Topology YANG Module Structure
+---------------------+
| ietf-network |
+----------^----------+
|
|
+---------------------+
|ietf-network-topology|
+----------^----------+
|
|
+----------^----------+
| ietf-l2-topology |
+---------------------+
The structure of the "ietf-l2-topology" YANG module is depicted in
the following tree diagram:
module: ietf-l2-topology
augment /nw:networks/nw:network/nw:network-types:
+--rw l2-topology!
augment /nw:networks/nw:network:
+--rw l2-topology-attributes
+--rw name? string
+--rw flags* l2-flag-type
augment /nw:networks/nw:network/nw:node:
+--rw l2-node-attributes
+--rw name? string
+--rw flags* node-flag-type
+--rw bridge-id* string
+--rw management-address* inet:ip-address
+--rw management-mac? yang:mac-address
+--rw management-vlan? string
augment /nw:networks/nw:network/nt:link:
+--rw l2-link-attributes
+--rw name? string
+--rw flags* link-flag-type
+--rw rate? uint64
+--rw delay? uint32
+--rw auto-nego? boolean
+--rw duplex? duplex-mode
augment /nw:networks/nw:network/nw:node/nt:termination-point:
+--rw l2-termination-point-attributes
+--rw interface-name? string
+--rw mac-address? yang:mac-address
+--rw port-number* uint32
+--rw unnumbered-id* uint32
+--rw encapsulation-type? identityref
+--rw outer-tag? dot1q-types:vid-range-type {VLAN}?
+--rw outer-tpid? dot1q-types:dot1q-tag-type {QinQ}?
+--rw inner-tag? dot1q-types:vid-range-type {VLAN}?
+--rw inner-tpid? dot1q-types:dot1q-tag-type {QinQ}?
+--rw lag? boolean
+--rw member-link-tp*
-> /nw:networks/network/node/nt:termination-point/tp-id
+--rw vxlan {VXLAN}?
+--rw vni-id? vni
notifications:
+---n l2-node-event
| +--ro event-type? l2-network-event-type
| +--ro node-ref?
-> /nw:networks/network[nw:network-id=current()
/../network-ref]/node/node-id
| +--ro network-ref? -> /nw:networks/network/network-id
| +--ro l2-topology!
| +--ro l2-node-attributes
| +--ro name? string
| +--ro flags* node-flag-type
| +--ro bridge-id* uint64
| +--ro management-address* inet:ip-address
| +--ro management-mac? yang:mac-address
| +--ro management-vlan? string
+---n l2-link-event
| +--ro event-type? l2-network-event-type
| +--ro link-ref?
-> /nw:networks/network[nw:network-id=current()
/../network-ref]/nt:link/link-id
| +--ro network-ref? -> /nw:networks/network/network-id
| +--ro l2-topology!
| +--ro l2-link-attributes
| +--ro name? string
| +--ro flags* link-flag-type
| +--ro rate? uint64
| +--ro delay? uint32
| +--ro auto-nego? boolean
| +--ro duplex? duplex-mode
+---n l2-termination-point-event
+--ro event-type? l2-network-event-type
+--ro tp-ref?
-> /nw:networks/network[nw:network-id=current()
/../network-ref]/node[nw:node-id=current()
/../node-ref]/nt:termination-point/tp-id
+--ro node-ref?
-> /nw:networks/network[nw:network-id=current()
/../network-ref]/node/node-id
+--ro network-ref? -> /nw:networks/network/network-id
+--ro l2-topology!
+--ro l2-termination-point-attributes
+--ro interface-name? string
+--ro mac-address? yang:mac-address
+--ro port-number* uint32
+--ro unnumbered-id* uint32
+--ro encapsulation-type? identityref
+--ro outer-tag? dot1q-types:vid-range-type {VLAN}?
+--ro outer-tpid? dot1q-types:dot1q-tag-type {QinQ}?
+--ro inner-tag? dot1q-types:vid-range-type {VLAN}?
+--ro inner-tpid? dot1q-types:dot1q-tag-type {QinQ}?
+--ro lag? boolean
+--ro member-link-tp*
-> /nw:networks/network/node/nt:termination-point/tp-id
+--ro vxlan {VXLAN}?
+--ro vni-id? vni
The Layer 2 Topology YANG module augments the "ietf-network" and
"ietf-network-topology" YANG modules as follows:
A new network type "l2-network-type" is introduced. This is
represented by a container object and is inserted under the
"network-types" container of the generic "ietf-network" module
defined in .
Additional network attributes are introduced in a grouping
"l2-network-attributes", which augments the "network" list of the
"ietf-network" module. The attributes include the Layer 2 network name
and a set of flags. Each type of flag is represented by a separate
identity.
Additional data objects for Layer 2 nodes are introduced by
augmenting the "node" list of the generic "ietf-network" module.
New objects include the Layer 2 node identifier, management address,
management MAC address, management VLAN, and a set of flags.
Additional data objects for Layer 2 termination points are
introduced by augmenting the "termination-point" list of the
"ietf-network-topology" module defined in .
New objects include the interface name, encapsulation type,
lag support indication, and attributes that are specific to
the Layer 2 termination point type.
Links in the "ietf-network-topology" module are augmented as well
with a set of Layer 2 parameters, allowing to associate a link with
a name, a set of Layer 2 link attributes, and flags.
Some optional Layer 2 technology-specific attributes are
introduced in this module as Layer 2 features because these
attributes may be useful to expose to above services/applications.
Note that learning or configuring advanced
Layer 2 technology-specific attributes is not within the scope of
the Layer
2 Topology YANG module; dedicated YANG modules should be used
instead (e.g., ).
Layer 2 Topology YANG ModuleThis module uses types defined in , , , and . It also references , , , and
.
module ietf-l2-topology {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-l2-topology";
prefix l2t;
import ietf-network {
prefix nw;
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
import ietf-network-topology {
prefix nt;
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
import ietf-inet-types {
prefix inet;
reference
"RFC 6991:Common YANG Data Types";
}
import ietf-yang-types {
prefix yang;
reference
"RFC 6991:Common YANG Data Types";
}
import iana-if-type {
prefix ianaift;
reference
"RFC 7224: IANA Interface Type YANG Module";
}
import ieee802-dot1q-types {
prefix dot1q-types;
reference
"IEEE Std 802.1Qcp-2018: Bridges and Bridged
Networks - Amendment: YANG Data Model";
}
organization
"IETF I2RS (Interface to the Routing System) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/i2rs>
WG List: <mailto:i2rs@ietf.org>
Editor: Jie Dong
<mailto:jie.dong@huawei.com>
Editor: Xiugang Wei
<mailto:weixiugang@huawei.com>
Editor: Qin Wu
<mailto:bill.wu@huawei.com>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Editor: Anders Liu
<mailto:andersliu@tencent.com>";
description
"This module defines a basic model for the Layer 2 topology
of a network.
Copyright (c) 2020 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 8944; see
the RFC itself for full legal notices.";
revision 2020-11-15 {
description
"Initial revision.";
reference
"RFC 8944: A YANG Data Model for Layer 2 Network Topologies";
}
feature VLAN {
description
"Enables VLAN tag support as defined in IEEE 802.1Q.";
reference
"IEEE Std 802.1Q-2014: Bridges and Bridged Networks";
}
feature QinQ {
description
"Enables QinQ double tag support as defined in IEEE 802.1ad.";
reference
"IEEE Std 802.1ad: Provider Bridges";
}
feature VXLAN {
description
"Enables VXLAN support as defined in RFC 7348.";
reference
"RFC 7348: Virtual eXtensible Local Area Network (VXLAN):
A Framework for Overlaying Virtualized Layer 2
Networks over Layer 3 Networks";
}
identity flag-identity {
description
"Base type for flags.";
}
identity eth-encapsulation-type {
base ianaift:iana-interface-type;
description
"Base identity from which specific Ethernet
encapsulation types are derived.";
reference
"RFC 7224: IANA Interface Type YANG Module";
}
identity ethernet {
base eth-encapsulation-type;
description
"Native Ethernet encapsulation.";
}
identity vlan {
base eth-encapsulation-type;
description
"VLAN encapsulation.";
}
identity qinq {
base eth-encapsulation-type;
description
"QinQ encapsulation.";
}
identity pbb {
base eth-encapsulation-type;
description
"Provider Backbone Bridging (PBB) encapsulation.
The PBB functions are developed in IEEE 802.1ah.";
}
identity trill {
base eth-encapsulation-type;
description
"Transparent Interconnection of Lots of Links (TRILL)
encapsulation.";
}
identity vpls {
base eth-encapsulation-type;
description
"Ethernet Virtual Private LAN Service (VPLS)
interface encapsulation.";
}
identity vxlan {
base eth-encapsulation-type;
description
"VXLAN Media Access Control (MAC) in UDP encapsulation.";
reference
"RFC 7348: Virtual eXtensible Local Area Network (VXLAN):
A Framework for Overlaying Virtualized Layer 2
Networks over Layer 3 Networks";
}
typedef vni {
type uint32 {
range "0..16777215";
}
description
"VXLAN Network Identifier or VXLAN Segment ID.
It allows up to 16 M VXLAN segments to coexist
within the same administrative domain.
The use of value '0' is implementation specific.";
reference
"RFC 7348: Virtual eXtensible Local Area Network (VXLAN):
A Framework for Overlaying Virtualized Layer 2
Networks over Layer 3 Networks";
}
typedef l2-flag-type {
type identityref {
base flag-identity;
}
description
"Base type for L2 flags. One example of L2 flag
type is trill, which represents the trill topology
type.";
}
typedef node-flag-type {
type identityref {
base flag-identity;
}
description
"Node flag attributes. The physical node can be
one example of a node flag attribute.";
}
typedef link-flag-type {
type identityref {
base flag-identity;
}
description
"Link flag attributes. One example of a link flag
attribute is the pseudowire.";
}
typedef l2-network-event-type {
type enumeration {
enum addition {
value 0;
description
"A Layer 2 node or link or termination-point
has been added.";
}
enum removal {
value 1;
description
"A Layer 2 node or link or termination-point
has been removed.";
}
enum update {
value 2;
description
"A Layer 2 node or link or termination-point
has been updated.";
}
}
description
"Layer 2 network event type for notifications.";
}
typedef duplex-mode {
type enumeration {
enum full-duplex {
description
"Indicates full-duplex mode.";
}
enum half-duplex {
description
"Indicates half-duplex mode.";
}
}
description
"Indicates the type of the duplex mode.";
}
grouping l2-network-type {
description
"Indicates the topology type to be L2.";
container l2-topology {
presence "Indicates L2 Network Topology.";
description
"The presence of the container node indicates
L2 Network Topology.";
}
}
grouping l2-topology-attributes {
description
"L2 topology scope attributes.";
container l2-topology-attributes {
description
"Contains L2 topology attributes.";
leaf name {
type string;
description
"Name of the topology.";
}
leaf-list flags {
type l2-flag-type;
description
"Topology flags.";
}
}
}
grouping l2-node-attributes {
description
"L2 node attributes.";
container l2-node-attributes {
description
"Contains L2 node attributes.";
leaf name {
type string;
description
"Node name.";
}
leaf-list flags {
type node-flag-type;
description
"Node flags. It can be used to indicate
node flag attributes.";
}
leaf-list bridge-id {
type string {
pattern '[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){7}';
}
description
"This is the bridge identifier represented as a
hexadecimal 8-octet string. It has 4 bits of
priority, 12 bits of Multiple Spanning Tree
Instance Identifier (MSTI-ID), and the base bridge
identifier. There may be multiple for each
spanning tree instance.";
reference
"RFC 7727: Spanning Tree Protocol (STP) Application of
the Inter-Chassis Communication Protocol
(ICCP)";
}
leaf-list management-address {
type inet:ip-address;
description
"IP address used for management purpose.";
}
leaf management-mac {
type yang:mac-address;
description
"This is a MAC address used for the bridge management.
It can be the Bridge Base VLAN ID (VID), interface
MAC address, or other. ";
}
leaf management-vlan {
type string;
description
"This is a VLAN that supports the management address.
The actual VLAN ID type and value would be a member of
this VLAN.";
}
}
}
grouping l2-link-attributes {
description
"L2 link attributes.";
container l2-link-attributes {
description
"Contains L2 link attributes.";
leaf name {
type string;
description
"Link name.";
}
leaf-list flags {
type link-flag-type;
description
"Link flags. It can be used to indicate
link flag attributes.";
}
leaf rate {
type uint64;
units "Kbps";
description
"Link rate. It specifies bandwidth requirements
associated with the specific link. The link
contains a source and a destination.";
}
leaf delay {
type uint32;
units "microseconds";
description
"Unidirectional link delay in
microseconds.";
}
leaf auto-nego {
type boolean;
default "true";
description
"Set to true if auto-negotiation is supported.
Set to false if auto-negotiation is not supported.";
}
leaf duplex {
type duplex-mode;
description
"Exposes the duplex mode, full-duplex or half-duplex.";
}
}
}
grouping l2-termination-point-attributes {
description
"L2 termination point attributes.";
container l2-termination-point-attributes {
description
"Containing L2 termination point attributes.";
leaf interface-name {
type string;
description
"Name of the interface. The name can (but does not
have to) correspond to an interface reference of a
containing node's interface, i.e., the path name of a
corresponding interface data node on the containing
node is reminiscent of data type interface-ref defined
in RFC 8343. It should be noted that data type
interface-ref of RFC 8343 cannot be used directly,
as this data type is used to reference an interface
in a datastore of a single node in the network, not
to uniquely reference interfaces across a network.";
}
leaf mac-address {
type yang:mac-address;
description
"Interface MAC address for logical link control.";
}
leaf-list port-number {
type uint32;
description
" List of port numbers of the bridge ports for which each
entry contains bridge management information.";
}
leaf-list unnumbered-id {
type uint32;
description
"List of unnumbered interface identifiers.
The unnumbered interface identifier will correspond to
the ifIndex value of the interface, i.e., the ifIndex
value of the ifEntry that represents the interface in
implementations where the Interfaces Group MIB
(RFC 2863) is supported.";
}
leaf encapsulation-type {
type identityref {
base eth-encapsulation-type;
}
description
"Encapsulation type of this
termination point.";
}
leaf outer-tag {
if-feature "VLAN";
type dot1q-types:vid-range-type;
description
"The outermost VLAN tag. It may include a list of VLAN
Ids or nonoverlapping VLAN ranges.";
}
leaf outer-tpid {
if-feature "QinQ";
type dot1q-types:dot1q-tag-type;
description
"Identifies a specific 802.1Q tag type of outermost VLAN
tag.";
}
leaf inner-tag {
if-feature "VLAN";
type dot1q-types:vid-range-type;
description
"The inner VLAN tag. It may include a list of VLAN
Ids or nonoverlapping VLAN ranges.";
}
leaf inner-tpid {
if-feature "QinQ";
type dot1q-types:dot1q-tag-type;
description
"Identifies a specific 802.1Q tag type of inner VLAN tag.";
}
leaf lag {
type boolean;
default "false";
description
"Defines whether lag is supported or not.
When it is set to true, the lag is supported.";
}
leaf-list member-link-tp {
when "../lag = 'true'" {
description
"Relevant only when the lag interface is supported.";
}
type leafref {
path "/nw:networks/nw:network/nw:node"
+ "/nt:termination-point/nt:tp-id";
}
description
"List of member link termination points associated with
specific L2 termination point.";
}
container vxlan {
when "derived-from-or-self(../encapsulation-type, "
+ "'l2t:vxlan')" {
description
"Only applies when the type of the Ethernet
encapsulation is 'vxlan'.";
}
if-feature "VXLAN";
leaf vni-id {
type vni;
description
"VXLAN Network Identifier (VNI).";
}
description
"Vxlan encapsulation type.";
}
}
}
augment "/nw:networks/nw:network/nw:network-types" {
description
"Introduces new network type for L2 topology.";
uses l2-network-type;
}
augment "/nw:networks/nw:network" {
when '/nw:networks/nw:network/nw:network-types/l2t:l2-topology' {
description
"Augmentation parameters apply only for networks
with L2 topology.";
}
description
"Configuration parameters for the L2 network
as a whole.";
uses l2-topology-attributes;
}
augment "/nw:networks/nw:network/nw:node" {
when '/nw:networks/nw:network/nw:network-types/l2t:l2-topology' {
description
"Augmentation parameters apply only for networks
with L2 topology.";
}
description
"Configuration parameters for L2 at the node
level.";
uses l2-node-attributes;
}
augment "/nw:networks/nw:network/nt:link" {
when '/nw:networks/nw:network/nw:network-types/l2t:l2-topology' {
description
"Augmentation parameters apply only for networks
with L2 topology.";
}
description
"Augments L2 topology link information.";
uses l2-link-attributes;
}
augment "/nw:networks/nw:network/nw:node/nt:termination-point" {
when '/nw:networks/nw:network/nw:network-types/l2t:l2-topology' {
description
"Augmentation parameters apply only for networks
with L2 topology.";
}
description
"Augments L2 topology termination point information.";
uses l2-termination-point-attributes;
}
notification l2-node-event {
description
"Notification event for L2 node.";
leaf event-type {
type l2-network-event-type;
description
"Event type.";
}
uses nw:node-ref;
uses l2-network-type;
uses l2-node-attributes;
}
notification l2-link-event {
description
"Notification event for L2 link.";
leaf event-type {
type l2-network-event-type;
description
"Event type.";
}
uses nt:link-ref;
uses l2-network-type;
uses l2-link-attributes;
}
notification l2-termination-point-event {
description
"Notification event for L2 termination point.";
leaf event-type {
type l2-network-event-type;
description
"Event type.";
}
uses nt:tp-ref;
uses l2-network-type;
uses l2-termination-point-attributes;
}
}
IANA ConsiderationsIANA has registered the following URIs in the
"ns" subregistry within "The IETF XML Registry" :
These modules are not maintained by IANA.Security ConsiderationsThe YANG modules specified in this document define a schema for data
that is designed to be accessed via network management protocols, such as
Network Configuration Protocol (NETCONF) or RESTCONF .
The lowest NETCONF layer is the secure transport layer, and the
mandatory-to-implement secure transport is Secure Shell (SSH) . The lowest RESTCONF layer is HTTPS, and the
mandatory-to-implement secure transport is TLS .The Network Configuration Access Control Model (NACM) provides the means to restrict access for particular
NETCONF or RESTCONF users to a preconfigured subset of all available
NETCONF or RESTCONF protocol operations and content.The Layer 2 topology module defines information that can be
configurable in certain instances, for example, in the case of virtual
topologies that can be created by client applications. In such cases, a
malicious client could introduce topologies that are undesired.
Specifically, a malicious client could attempt to remove or add a node,
a link, or a termination point by creating or deleting corresponding
elements in the node, link, and termination point lists, respectively.
In the case of a topology that is learned, the server will automatically
prohibit such misconfiguration attempts. In the case of a topology that
is configured, i.e., whose origin is "intended", the undesired
configuration could become effective and be reflected in the operational
state datastore , leading to
disruption of services provided
via this topology. For those reasons, it is important that the NACM is
vigorously applied to prevent topology misconfiguration by unauthorized
clients.There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., config true, which is the default).
These data nodes may be considered sensitive or vulnerable in some
network environments. Write operations (e.g., edit-config) to these data
nodes without proper protection can have a negative effect on network
operations. These are the subtrees and data nodes and their
sensitivity/vulnerability:
l2-network-attributes:
A malicious client could attempt to
sabotage the configuration of any of the contained attributes, such
as the name or the flag data nodes.
l2-node-attributes:
A malicious client could attempt to sabotage
the configuration of important node attributes, such as the name or
the management-address.
l2-link-attributes:
A malicious client could attempt to sabotage
the configuration of important link attributes, such as the rate or
the delay data nodes.
l2-termination-point-attributes:
A malicious client could attempt
to sabotage the configuration of important termination point
attributes (e.g., 'maximum-frame-size').
Some of the readable data nodes in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. In particular, the YANG module for
Layer 2 topology may expose sensitive information, for example, the MAC
addresses of devices or VLAN/VXLAN identifiers. Unrestricted use of such
information can lead to privacy violations. For example, listing MAC
addresses in a network allows monitoring of devices and their movements.
Location information can be derived from MAC addresses of network
devices, bypassing protection of location information by the Operating
System.ReferencesNormative ReferencesKey words for use in RFCs to Indicate Requirement LevelsIn many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.The IETF XML RegistryThis document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas.YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK]Network Configuration Protocol (NETCONF)The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK]Using the NETCONF Protocol over Secure Shell (SSH)This document describes a method for invoking and running the Network Configuration Protocol (NETCONF) within a Secure Shell (SSH) session as an SSH subsystem. This document obsoletes RFC 4742. [STANDARDS-TRACK]Common YANG Data TypesThis document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021.IANA Interface Type YANG ModuleThis document defines the initial version of the iana-if-type YANG module.Virtual eXtensible Local Area Network (VXLAN): A Framework for Overlaying Virtualized Layer 2 Networks over Layer 3 NetworksThis document describes Virtual eXtensible Local Area Network (VXLAN), which is used to address the need for overlay networks within virtualized data centers accommodating multiple tenants. The scheme and the related protocols can be used in networks for cloud service providers and enterprise data centers. This memo documents the deployed VXLAN protocol for the benefit of the Internet community.The YANG 1.1 Data Modeling LanguageYANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF).RESTCONF ProtocolThis document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF).Ambiguity of Uppercase vs Lowercase in RFC 2119 Key WordsRFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.Network Configuration Access Control ModelThe standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model.This document obsoletes RFC 6536.A YANG Data Model for Network TopologiesThis document defines an abstract (generic, or base) YANG data model for network/service topologies and inventories. The data model serves as a base model that is augmented with technology-specific details in other, more specific topology and inventory data models.The Transport Layer Security (TLS) Protocol Version 1.3This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery.This document updates RFCs 5705 and 6066, and obsoletes RFCs 5077, 5246, and 6961. This document also specifies new requirements for TLS 1.2 implementations.Informative ReferencesSummary of I2RS Use Case Requirements The I2RS Working Group (WG) has described a set of use cases that the
I2RS systems could fulfil. This document summarizes these use cases.
It is designed to provide requirements that will aid the design of
the I2RS architecture, Information Models, Data Models, Security, and
protocols.
Work in ProgressIEEE Standard for Local and metropolitan area networks - Station and Media Access Control Connectivity DiscoveryIEEEIEEE Standard for Local and Metropolitan Area Networks--Virtual Bridged Local Area Networks--Amendment 4: Provider BridgesIEEEIEEE Standard for Local and metropolitan area networks -- Virtual Bridged Local Area Networks Amendment 7: Provider Backbone BridgesIEEEIEEE Standard for Local and metropolitan area networks--Bridges and Bridged NetworksIEEEIEEE Standard for Local and metropolitan area networks--Bridges and Bridged Networks--Amendment 30: YANG Data ModelIEEESpanning Tree Protocol (STP) Application of the Inter-Chassis Communication Protocol (ICCP)The Inter-Chassis Communication Protocol (ICCP) supports an inter-chassis redundancy mechanism that is used to support high network availability.In this document, Provider Edge (PE) devices in a Redundancy Group (RG) running ICCP are used to offer multihomed connectivity to Spanning Tree Protocol (STP) networks to improve availability of the STP networks. The ICCP TLVs and usage for the ICCP STP application are defined.JSON Encoding of Data Modeled with YANGThis document defines encoding rules for representing configuration data, state data, parameters of Remote Procedure Call (RPC) operations or actions, and notifications defined using YANG as JavaScript Object Notation (JSON) text.YANG Tree DiagramsThis document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language.Network Management Datastore Architecture (NMDA)Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950.TRILL YANG Data Model This document defines a YANG data model for TRILL protocol.
Work in ProgressCompanion YANG Module for Non-NMDA-Compliant ImplementationsThe YANG module ietf-l2-topology defined in this document augments
two modules, "ietf-network" and "ietf-network-topology", that are
designed to be used in conjunction with implementations that support the
Network Management Datastore Architecture (NMDA) defined in . In order to allow implementations
to use the model
even in cases when NMDA is not supported, a set of companion modules
have been defined that represent a state model of networks and network
topologies, "ietf-network-state" and "ietf-network-topology-state",
respectively.In order to be able to use the model for Layer 2 topologies defined
in this document in conjunction with non-NMDA-compliant implementations,
a corresponding companion module is defined that represents the
operational state of Layer 2 network topologies. The module
"ietf-l2-topology-state" mirrors the module "ietf-l2-topology" defined
in . However, it augments "ietf-network-state"
and "ietf-network-topology-state" (instead of "ietf-network" and
"ietf-network-topology") and all its data nodes are
nonconfigurable.The companion module "ietf-l2-topology" SHOULD NOT be supported by
implementations that support NMDA. It is for this reason that this
module is defined in the informative appendix.As the structure of this module mirrors that of its underlying
modules, the YANG tree is not depicted separately.
module ietf-l2-topology-state {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-l2-topology-state";
prefix l2t-s;
import ietf-network-state {
prefix nw-s;
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
import ietf-network-topology-state {
prefix nt-s;
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
import ietf-l2-topology {
prefix l2t;
reference
"RFC 8944: A YANG Data Model for Layer 2 Network Topologies";
}
organization
"IETF I2RS (Interface to the Routing System) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/i2rs/>
WG List: <mailto:i2rs@ietf.org>
Editor: Jie Dong
<mailto:jie.dong@huawei.com>
Editor: Xiugang Wei
<mailto:weixiugang@huawei.com>
Editor: Qin Wu
<mailto:bill.wu@huawei.com>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Editor: Anders Liu
<andersliu@tencent.com>";
description
"This module defines a model for Layer 2 Network Topology
state, representing topology that either is learned or
results from applying topology that has been configured per
the 'ietf-l2-topology' model, mirroring the
corresponding data nodes in this model.
This model mirrors 'ietf-l2-topology' but contains only
read-only state data. The model is not needed when the
underlying implementation infrastructure supports the
Network Management Datastore Architecture (NMDA).
Copyright (c) 2020 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 8944; see
the RFC itself for full legal notices.";
revision 2020-11-15 {
description
"Initial revision.";
reference
"RFC 8944: A YANG Data Model for Layer 2 Network Topologies";
}
/*
* Data nodes
*/
augment "/nw-s:networks/nw-s:network/nw-s:network-types" {
description
"Introduces a new network type for L2 topology.";
uses l2t:l2-network-type;
}
augment "/nw-s:networks/nw-s:network" {
when 'nw-s:network-types/l2t-s:l2-topology' {
description
"Augmentation parameters apply only for networks
with L2 topology.";
}
description
"Configuration parameters for the L2 network
as a whole.";
uses l2t:l2-topology-attributes;
}
augment "/nw-s:networks/nw-s:network/nw-s:node" {
when '../nw-s:network-types/l2t-s:l2-topology' {
description
"Augmentation parameters apply only for networks
with L2 topology.";
}
description
"Configuration parameters for L2 at the node
level.";
uses l2t:l2-node-attributes;
}
augment "/nw-s:networks/nw-s:network/nt-s:link" {
when '../nw-s:network-types/l2t-s:l2-topology' {
description
"Augmentation parameters apply only for networks
with L2 topology.";
}
description
"Augments L2 topology link information.";
uses l2t:l2-link-attributes;
}
augment "/nw-s:networks/nw-s:network/nw-s:node/"
+ "nt-s:termination-point" {
when '../../nw-s:network-types/l2t-s:l2-topology' {
description
"Augmentation parameters apply only for networks
with L2 topology.";
}
description
"Augments L2 topology termination point information.";
uses l2t:l2-termination-point-attributes;
}
/*
* Notifications
*/
notification l2-node-event {
description
"Notification event for L2 node.";
leaf event-type {
type l2t:l2-network-event-type;
description
"Event type.";
}
uses nw-s:node-ref;
uses l2t:l2-network-type;
uses l2t:l2-node-attributes;
}
notification l2-link-event {
description
"Notification event for an L2 link.";
leaf event-type {
type l2t:l2-network-event-type;
description
"Event type.";
}
uses nt-s:link-ref;
uses l2t:l2-network-type;
uses l2t:l2-link-attributes;
}
notification l2-termination-point-event {
description
"Notification event for L2 termination point.";
leaf event-type {
type l2t:l2-network-event-type;
description
"Event type.";
}
uses nt-s:tp-ref;
uses l2t:l2-network-type;
uses l2t:l2-termination-point-attributes;
}
}
An ExampleThis section contains an example of an instance data tree in JSON
encoding . The example instantiates
"ietf-l2-topology" for the topology that is depicted in the following
diagram. There are three nodes: D1, D2, and D3. D1 has three termination
points: 1-0-1, 1-2-1, and 1-3-1. D2 has three termination points as
well: 2-1-1, 2-0-1, and 2-3-1. D3 has two termination points: 3-1-1 and
3-2-1. For termination point 1-0-1, it provides lag support and has two
member link termination points: 1-0-1-1 and 1-0-1-2. In addition, there are
six links, two between each pair of nodes with one going in each
direction.A Network Topology Example
+------------+ +------------+
| D1 | | D2 |
1-0-1-1 /-\ /-\ /-\ /-\
<--------->| | 1-0-1 | |---------------->| | 2-1-1 | |
1-0-1-2 | | 1-2-1 | |<----------------| | 2-0-1 | |
<--------> \-/ 1-3-1 \-/ \-/ 2-3-1 \-/
| /----\ | | /----\ |
+---| |---+ +---| |---+
\----/ \----/
A | A |
| | | |
| | | |
| | +------------+ | |
| | | D3 | | |
| | /-\ /-\ | |
| +----->| | 3-1-1 | |-------+ |
+---------| | 3-2-1 | |<---------+
\-/ \-/
| |
+------------+
The corresponding instance data tree is depicted below:
{
"ietf-network:networks": {
"network": [
{
"network-id": "l2-topo-example",
"node": [
{
"node-id": "D1",
"ietf-network-topology:termination-point": [
{
"tp-id": "1-0-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:d0",
"lag": true,
"member-link-tp": [
"1-0-1-1",
"1-0-1-2"
]
}
},
{
"tp-id": "1-0-1-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:d3"
}
},
{
"tp-id": "1-0-1-2",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:d4"
}
},
{
"tp-id": "1-2-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:d1"
}
},
{
"tp-id": "1-3-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:d2"
}
}
],
"ietf-l2-topology:l2-node-attributes": {
"management-address": [
"192.0.2.1",
"2001:db8:0:1::"
]
}
},
{
"node-id": "D2",
"ietf-network-topology:termination-point": [
{
"tp-id": "2-0-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:e0"
}
},
{
"tp-id": "2-1-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:e1"
}
},
{
"tp-id": "2-3-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:e2"
}
}
],
"ietf-l2-topology:l2-node-attributes": {
"management-address": [
"192.0.2.2",
"2001:db8:0:2::"
]
}
},
{
"node-id": "D3",
"ietf-network-topology:termination-point": [
{
"tp-id": "3-1-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:f0"
}
},
{
"tp-id": "3-2-1",
"ietf-l2-topology:l2-termination-point-attributes": {
"mac-address": "00:00:5e:00:53:f1"
}
}
],
"ietf-l2-topology:l2-node-attributes": {
"management-address": [
"192.0.2.3",
"2001:db8:0:3::"
]
}
}
],
"ietf-network-topology:link": [
{
"link-id": "D1,1-2-1,D2,2-1-1",
"source": {
"source-node": "D1",
"source-tp": "1-2-1"
},
"destination": {
"dest-node": "D2",
"dest-tp": "2-1-1"
},
"ietf-l2-topology:l2-link-attributes": {
"rate": "1000"
}
},
{
"link-id": "D2,2-1-1,D1,1-2-1",
"source": {
"source-node": "D2",
"source-tp": "2-1-1"
},
"destination": {
"dest-node": "D1",
"dest-tp": "1-2-1"
},
"ietf-l2-topology:l2-link-attributes": {
"rate": "1000"
}
},
{
"link-id": "D1,1-3-1,D3,3-1-1",
"source": {
"source-node": "D1",
"source-tp": "1-3-1"
},
"destination": {
"dest-node": "D3",
"dest-tp": "3-1-1"
},
"ietf-l2-topology:l2-link-attributes": {
"rate": "1000"
}
},
{
"link-id": "D3,3-1-1,D1,1-3-1",
"source": {
"source-node": "D3",
"source-tp": "3-1-1"
},
"destination": {
"dest-node": "D1",
"dest-tp": "1-3-1"
},
"ietf-l2-topology:l2-link-attributes": {
"rate": "1000"
}
},
{
"link-id": "D2,2-3-1,D3,3-2-1",
"source": {
"source-node": "D2",
"source-tp": "2-3-1"
},
"destination": {
"dest-node": "D3",
"dest-tp": "3-2-1"
},
"ietf-l2-topology:l2-link-attributes": {
"rate": "1000"
}
},
{
"link-id": "D3,3-2-1,D2,2-3-1",
"source": {
"source-node": "D3",
"source-tp": "3-2-1"
},
"destination": {
"dest-node": "D2",
"dest-tp": "2-3-1"
},
"ietf-l2-topology:l2-link-attributes": {
"rate": "1000"
}
}
]
}
]
}
}
AcknowledgementsThe authors would like to acknowledge the comments and suggestions
received from , , , , , , , , , , , and .Many thanks to for the
yang-doctors review.Authors' AddressesHuaweiNo. 156 Beiqing Rd.Huawei CampusBeijing100095Chinajie.dong@huawei.comHuaweiNo. 156 Beiqing Rd.Huawei CampusBeijing100095Chinaweixiugang@huawei.comHuawei101 Software AvenueYuhua DistrictNanjing210012Chinabill.wu@huawei.comOrangeRennes 35000Francemohamed.boucadair@orange.comTecent38 Haidian StYinke BuildingHaidian DistrictBeijing100080Chinaandersliu@tencent.com