Internet DRAFT - draft-ietf-mpls-base-yang
draft-ietf-mpls-base-yang
MPLS Working Group T. Saad
Internet-Draft Juniper Networks
Intended status: Standards Track K. Raza
Expires: April 29, 2021 R. Gandhi
Cisco Systems Inc
X. Liu
Volta Networks
V. Beeram
Juniper Networks
October 26, 2020
A YANG Data Model for MPLS Base
draft-ietf-mpls-base-yang-17
Abstract
This document contains a specification of the MPLS base YANG data
model. The MPLS base YANG data model serves as a base framework for
configuring and managing an MPLS switching subsystem on an MPLS-
enabled router. It is expected that other MPLS YANG data models
(e.g. MPLS Label Switched Path (LSP) Static, LDP or RSVP-TE YANG
models) will augment the MPLS base YANG data model.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 29, 2021.
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
Saad, et al. Expires April 29, 2021 [Page 1]
Internet-Draft MPLS Base YANG Data Model October 2020
(https://trustee.ietf.org/license-info) 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
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Acronyms and Abbreviations . . . . . . . . . . . . . . . 3
2. MPLS Base Model . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Model Overview . . . . . . . . . . . . . . . . . . . . . 4
2.2. Model Organization . . . . . . . . . . . . . . . . . . . 4
2.3. Model Design . . . . . . . . . . . . . . . . . . . . . . 6
2.4. Model Tree Diagram . . . . . . . . . . . . . . . . . . . 8
2.5. Model YANG Module . . . . . . . . . . . . . . . . . . . . 9
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
4. Security Considerations . . . . . . . . . . . . . . . . . . . 20
5. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 21
6. Appendix A. Data Tree Instance Example . . . . . . . . . . . 21
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 27
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
8.1. Normative References . . . . . . . . . . . . . . . . . . 27
8.2. Informative References . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29
1. Introduction
A core routing YANG data model is defined in [RFC8349], and it
provides a basis for the development of routing data models for
specific Address Families (AFs). Specifically, [RFC8349] defines a
model for a generic Routing Information Base (RIB) that is Address-
Family (AF) agnostic. [RFC8349] also defines two instances of RIBs
based on the generic RIB model for IPv4 and IPv6 AFs.
The MPLS base model that is defined in this document augments the
generic RIB model defined in [RFC8349] with additional data that
enables MPLS forwarding for the specific destination prefix(es)
present in the AF RIB(s) as described in the MPLS architecture
document [RFC3031].
The MPLS base model also defines a new instance of the generic RIB
YANG data model as defined in [RFC8349] to store native MPLS routes.
The native MPLS RIB instance stores route(s) that are not associated
with other AF instance RIBs (such as IPv4, or IPv6 instance RIB(s)),
Saad, et al. Expires April 29, 2021 [Page 2]
Internet-Draft MPLS Base YANG Data Model October 2020
but are enabled for MPLS forwarding. Examples of such native MPLS
routes are routes programmed by RSVP on transit MPLS router(s) along
the path of a Label Switched Path (LSP). Other example(s) are MPLS
routes that cross-connect to specific Layer-2 adjacencies, such as
Layer-2 Attachment Circuit(s) (ACs)), or Layer-3 adjacencies, such as
Segment-Routing (SR) Adjacency Segments (Adj-SIDs) described in
[RFC8402].
The MPLS base YANG data model serves as a basis for future
development of MPLS YANG data models covering more-sophisticated MPLS
feature(s) and sub-system(s). The main purpose is to provide
essential building blocks for other YANG data models involving
different control-plane protocols, and MPLS functions.
To this end, it is expected that the MPLS base data model will be
augmented by a number of other YANG modules developed at IETF (e.g.
by TEAS and MPLS working groups).
The YANG module in this document conforms to the Network Management
Datastore Architecture (NMDA) [RFC8342].
1.1. Terminology
The terminology for describing YANG data models is found in
[RFC7950].
1.2. Acronyms and Abbreviations
MPLS: Multiprotocol Label Switching
RIB: Routing Information Base
LSP: Label Switched Path
LSR: Label Switching Router
LER: Label Edge Router
FEC: Forwarding Equivalence Class
NHLFE: Next Hop Label Forwarding Entry
ILM: Incoming Label Map
Saad, et al. Expires April 29, 2021 [Page 3]
Internet-Draft MPLS Base YANG Data Model October 2020
2. MPLS Base Model
This document describes the 'ietf-mpls' YANG module that provides
base components of the MPLS data model. It is expected that other
MPLS YANG modules will augment 'ietf-mpls' YANG module for other MPLS
extension to provision Label Switched Paths (LSPs) (e.g. MPLS
Static, MPLS LDP or MPLS RSVP-TE LSP(s)).
2.1. Model Overview
This document models MPLS labeled routes as an augmentation of the
generic routing RIB data model as defined in [RFC8349]. For example,
IP prefix routes (e.g. routes stored in IPv4 or IPv6 RIBs) are
augmented to carry additional data to enable it for MPLS forwarding.
This document also defines a new instance of the generic RIB defined
in [RFC8349] to store native MPLS route(s) (described further in
Section 2.3) by extending the identity 'address-family' defined in
[RFC8349] with a new "mpls" identity as suggested in Section 3 of
[RFC8349].
2.2. Model Organization
Routing +---------------+ v: import
YANG module | ietf-routing | o: augment
+---------------+
o
|
v
MPLS base +-----------+ v: import
YANG module | ietf-mpls | o: augment
+-----------+
o o------+
| \
v v
+-------------------+ +---------------------+
MPLS Static | ietf-mpls-static@ | | ietf-mpls-ldp.yang@ | . .
LSP YANG +-------------------+ +---------------------+
module
@: not in this document, shown for illustration only
Figure 1: Relationship between MPLS modules
The 'ietf-mpls' YANG module defines the following identities:
mpls:
Saad, et al. Expires April 29, 2021 [Page 4]
Internet-Draft MPLS Base YANG Data Model October 2020
This identity extends the 'address-family' identity for RIB
instance(s) identity as defined in [RFC8349] to represent the
native MPLS RIB instance.
label-block-alloc-mode:
A base YANG identity for supported label block allocation mode(s).
The 'ietf-mpls' YANG module contains the following high-level types
and groupings:
mpls-operations-type:
An enumeration type that represents support for possible MPLS
operation types (impose-and-forward, pop-and-forward, pop-impose-
and-forward, and pop-and-lookup)
nhlfe-role:
An enumeration type that represents the role of the NHLFE entry.
nhlfe-single-contents:
A YANG grouping that describes single Next Hop Label Forwarding
Entry (NHLFE) and its associated parameters as described in the
MPLS architecture document [RFC3031]. This grouping is specific
to the case when a single next-hop is associated with the route.
The NHLFE is used when forwarding labeled packet. It contains the
following information:
1. the packet's next hop. For 'nhlfe-single-contents' only a single
next hop is expected, while for 'nhlfe-multiple-contents'
multiple next hops are possible.
2. the operation to perform on the packet's label stack; this can be
one of the following operations: a) replace the label at the top
of the label stack with one or more specified new label b) pop
the label stack c) replace the label at the top of the label
stack with a specified new label, and then push one or more
specified new labels onto the label stack. d) push one or more
label(s) on an unlabeled packet
It may also contain:
Saad, et al. Expires April 29, 2021 [Page 5]
Internet-Draft MPLS Base YANG Data Model October 2020
d) the data link encapsulation to use when transmitting the packet
e) the way to encode the label stack when transmitting the packet
f) any other information needed in order to properly dispose of
the packet.
nhlfe-multiple-contents:
A YANG grouping that describes a set of NHLFE(s) and their
associated parameters as described in the MPLS architecture
document [RFC3031]. This grouping is used when multiple next-hops
are associated with the route.
interfaces-mpls:
A YANG grouping that describes the list of MPLS enabled interfaces
on a device.
label-blocks:
A YANG grouping that describes the list of assigned MPLS label
blocks and their properties.
rib-mpls-properties:
A YANG grouping for the augmentation of the generic RIB with MPLS
label forwarding data as defined in [RFC3031].
rib-active-route-mpls-input:
A YANG grouping for the augmentation to the 'active-route' RPC
that is specific to the MPLS RIB instance.
2.3. Model Design
The MPLS routing model is based on the core routing data model
defined in [RFC8349]. Figure 2 shows the extensions introduced by
the MPLS base model on defined RIB(s).
Saad, et al. Expires April 29, 2021 [Page 6]
Internet-Draft MPLS Base YANG Data Model October 2020
+-----------------+
| MPLS base model |
+-----------------+
____/ | |_____ |________
/ | \ \
/ | \ \
o o o +
+---------+ +---------+ +--------+ +-----------+
| RIB(v4) | | RIB(v6) | | RIB(x) | | RIB(mpls) |
+---------+ +---------+ +--------+ +-----------+
+: created by the MPLS base model
o: augmented by the MPLS base model
Figure 2: Relationship between MPLS model and RIB instances
As shown in Figure 2, the MPLS base YANG data model augments defined
instance(s) of AF RIB(s) with additional data that enables MPLS
forwarding for destination prefix(es) store in such RIB(s). For
example, an IPv4 prefix stored in RIB(v4) is augmented to carry a
MPLS local label and per next-hop remote label(s) to enable MPLS
forwarding for such prefix.
The MPLS base model also creates a separate instance of the generic
RIB model defined in [RFC8349] to store MPLS native route(s) that are
enabled for MPLS forwarding, but not stored in other AF RIB(s).
Some examples of such native MPLS routes are:
o routes programmed by RSVP on Label Switched Router(s) (LSRs) along
the path of a Label Switched Path (LSP),
o routes that cross-connect an MPLS local label to a Layer-2, or
Layer-3 VRF,
o routes that cross-connect an MPLS local label to a specific
Layer-2 adjacency or interface, such as Layer-2 Attachment
Circuit(s) (ACs), or
o routes that cross-connect an MPLS local label to a Layer-3
adjacency or interface - such as MPLS Segment-Routing (SR)
Adjacency Segments (Adj-SIDs), SR MPLS Binding SIDs, etc. as
defined in [RFC8402].
Saad, et al. Expires April 29, 2021 [Page 7]
Internet-Draft MPLS Base YANG Data Model October 2020
2.4. Model Tree Diagram
The MPLS base tree diagram that follows the notation defined in
[RFC8340] is shown in Figure 3.
module: ietf-mpls
augment /rt:routing:
+--rw mpls
+--rw ttl-propagate? boolean
+--rw mpls-label-blocks
| +--rw mpls-label-block* [index]
| +--rw index string
| +--rw start-label? rt-types:mpls-label
| +--rw end-label? rt-types:mpls-label
| +--rw block-allocation-mode? identityref
| +--ro inuse-labels-count? yang:gauge32
+--rw interfaces
+--rw interface* [name]
+--rw name if:interface-ref
+--rw mpls-enabled? boolean
+--rw maximum-labeled-packet? uint32
augment /rt:routing/rt:ribs/rt:rib/rt:routes/rt:route:
+--ro mpls-enabled? boolean
+--ro mpls-local-label? rt-types:mpls-label
+--ro destination-prefix? -> ../mpls-local-label
+--ro route-context? string
augment /rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/rt:next-hop
/rt:next-hop-options/rt:simple-next-hop:
+--ro mpls-label-stack
+--ro entry* [id]
+--ro id uint8
+--ro label? rt-types:mpls-label
+--ro ttl? uint8
+--ro traffic-class? uint8
augment /rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/rt:next-hop
/rt:next-hop-options/rt:next-hop-list/rt:next-hop-list
/rt:next-hop:
+--ro index? string
+--ro backup-index? string
+--ro loadshare? uint16
+--ro role? nhlfe-role
+--ro mpls-label-stack
+--ro entry* [id]
+--ro id uint8
+--ro label? rt-types:mpls-label
+--ro ttl? uint8
+--ro traffic-class? uint8
augment /rt:routing/rt:ribs/rt:rib/rt:active-route/rt:input:
Saad, et al. Expires April 29, 2021 [Page 8]
Internet-Draft MPLS Base YANG Data Model October 2020
+---w destination-address? -> ../mpls-local-label
+---w mpls-local-label? rt-types:mpls-label
augment /rt:routing/rt:ribs/rt:rib/rt:active-route/rt:output
/rt:route/rt:next-hop/rt:next-hop-options
/rt:simple-next-hop:
+-- mpls-label-stack
+-- entry* [id]
+-- id uint8
+-- label? rt-types:mpls-label
+-- ttl? uint8
+-- traffic-class? uint8
augment /rt:routing/rt:ribs/rt:rib/rt:active-route/rt:output
/rt:route/rt:next-hop/rt:next-hop-options
/rt:next-hop-list/rt:next-hop-list/rt:next-hop:
+-- index? string
+-- backup-index? string
+-- loadshare? uint16
+-- role? nhlfe-role
+-- mpls-label-stack
+-- entry* [id]
+-- id uint8
+-- label? rt-types:mpls-label
+-- ttl? uint8
+-- traffic-class? uint8
Figure 3: MPLS Base tree diagram
2.5. Model YANG Module
This section describes the 'ietf-mpls' YANG module that provides base
components of the MPLS data model. Other YANG module(s) may import
and augment the base MPLS module to add feature specific data.
The ietf-mpls YANG module imports the following YANG modules:
o ietf-routing defined in [RFC8349]
o ietf-routing-types defined in [RFC8294]
o ietf-interfaces defined in [RFC8343]
This YANG module also references the following RFCs in defining the
types and YANG grouping of the YANG module: [RFC3032], [RFC3031], and
[RFC7424].
<CODE BEGINS> file "ietf-mpls@2020-10-26.yang"
module ietf-mpls {
yang-version 1.1;
Saad, et al. Expires April 29, 2021 [Page 9]
Internet-Draft MPLS Base YANG Data Model October 2020
namespace "urn:ietf:params:xml:ns:yang:ietf-mpls";
/* Replace with IANA when assigned */
prefix mpls;
import ietf-routing {
prefix rt;
reference
"RFC8349: A YANG Data Model for Routing Management";
}
import ietf-routing-types {
prefix rt-types;
reference
"RFC8294:Common YANG Data Types for the Routing Area";
}
import ietf-yang-types {
prefix yang;
reference
"RFC6991: Common YANG Data Types";
}
import ietf-interfaces {
prefix if;
reference
"RFC8343: A YANG Data Model for Interface Management";
}
organization
"IETF MPLS Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/mpls/>
WG List: <mailto:mpls@ietf.org>
Editor: Tarek Saad
<mailto:tsaad@juniper.net>
Editor: Kamran Raza
<mailto:skraza@cisco.com>
Editor: Rakesh Gandhi
<mailto:rgandhi@cisco.com>
Editor: Xufeng Liu
<mailto: xufeng.liu.ietf@gmail.com>
Editor: Vishnu Pavan Beeram
<mailto:vbeeram@juniper.net>";
Saad, et al. Expires April 29, 2021 [Page 10]
Internet-Draft MPLS Base YANG Data Model October 2020
description
"This YANG module defines the essential components for the
management of the MPLS subsystem. The model fully conforms
to the Network Management Datastore Architecture (NMDA).
Copyright (c) 2018 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
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2020-10-26 {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Data Model for base MPLS";
}
/* Identities */
identity mpls {
base rt:address-family;
description
"This identity represents the MPLS address family.";
}
identity mpls-unicast {
base mpls:mpls;
description
"This identity represents the MPLS unicast address family.";
}
identity label-block-alloc-mode {
description
"Base identity for label-block allocation mode.";
}
Saad, et al. Expires April 29, 2021 [Page 11]
Internet-Draft MPLS Base YANG Data Model October 2020
identity label-block-alloc-mode-manager {
base label-block-alloc-mode;
description
"Label block allocation on reserved block
is managed by label manager.";
}
identity label-block-alloc-mode-application {
base label-block-alloc-mode;
description
"Label block allocation on reserved block
is managed by application.";
}
/**
* Typedefs
*/
typedef mpls-operations-type {
type enumeration {
enum impose-and-forward {
description
"Operation impose outgoing label(s) and forward to
next-hop.";
}
enum pop-and-forward {
description
"Operation pop incoming label and forward to next-hop.";
}
enum pop-impose-and-forward {
description
"Operation pop incoming label, impose one or more
outgoing label(s) and forward to next-hop.";
}
enum swap-and-forward {
description
"Operation swap incoming label, with outgoing label and
forward to next-hop.";
}
enum pop-and-lookup {
description
"Operation pop incoming label and perform a lookup.";
}
}
description
"MPLS operations types.";
}
Saad, et al. Expires April 29, 2021 [Page 12]
Internet-Draft MPLS Base YANG Data Model October 2020
typedef nhlfe-role {
type enumeration {
enum primary {
description
"Next-hop acts as primary for carrying traffic.";
}
enum backup {
description
"Next-hop acts as backup.";
}
enum primary-and-backup {
description
"Next-hop acts as primary and backup simultaneously
for carry traffic.";
}
}
description
"The next-hop role.";
}
grouping nhlfe-single-contents {
description
"A grouping that describes single Next Hop Label Forwarding
Entry (NHLFE) and its associated parameters as described in
the MPLS architecture. This grouping is specific to the case
when a single next-hop is associated with the route.";
uses rt-types:mpls-label-stack;
}
grouping nhlfe-multiple-contents {
description
"A grouping that describes a set of NHLFE(s) and their
associated parameters as described in the MPLS architecture.
This grouping is used when multiple next-hops are associated
with the route.";
leaf index {
type string;
description
"A user-specified identifier utilised to uniquely
reference the next-hop entry in the next-hop list.
The value of this index has no semantic meaning
other than for referencing the entry.";
}
leaf backup-index {
type string;
description
"A user-specified identifier utilised to uniquely
reference the backup next-hop entry in the NHLFE list.
Saad, et al. Expires April 29, 2021 [Page 13]
Internet-Draft MPLS Base YANG Data Model October 2020
The value of this index has no semantic meaning
other than for referencing the entry.";
reference
"RFC4090 and RFC5714";
}
leaf loadshare {
type uint16;
default "1";
description
"This value is used to compute a loadshare to perform un-equal
load balancing when multiple outgoing next-hop(s) are
specified. A share is computed as a ratio of this number to the
total under all next-hops(s).";
reference
"RFC7424, section 5.4,
RFC3031, section 3.11 and 3.12.";
}
leaf role {
type nhlfe-role;
description
"NHLFE role.";
}
uses nhlfe-single-contents;
}
grouping interfaces-mpls {
description
"List of MPLS interfaces.";
container interfaces {
description
"List of MPLS enabled interaces.";
list interface {
key "name";
description
"MPLS enabled interface entry.";
leaf name {
type if:interface-ref;
description
"A reference to the name of a interface in the system that
is to be enabled for MPLS.";
}
leaf mpls-enabled {
type boolean;
default "false";
description
"'true' if mpls encapsulation is enabled on the interface.
'false' if mpls encapsulation is disabled on the
interface.";
Saad, et al. Expires April 29, 2021 [Page 14]
Internet-Draft MPLS Base YANG Data Model October 2020
}
leaf maximum-labeled-packet {
type uint32;
units "octets";
description
"Maximum labeled packet size.";
reference
"RFC3032, section 3.2.";
}
}
}
}
grouping globals {
description
"MPLS global configuration grouping.";
leaf ttl-propagate {
type boolean;
default "true";
description
"Propagate TTL between IP and MPLS.";
}
}
grouping label-blocks {
description
"Label-block allocation grouping.";
container mpls-label-blocks {
description
"Label-block allocation container.";
list mpls-label-block {
key "index";
description
"List of MPLS label-blocks.";
leaf index {
type string;
description
"A user-specified identifier utilised to uniquely
reference an MPLS label block.";
}
leaf start-label {
type rt-types:mpls-label;
must '. <= ../end-label' {
error-message
"The start-label must be less than or equal "
+ "to end-label";
}
description
Saad, et al. Expires April 29, 2021 [Page 15]
Internet-Draft MPLS Base YANG Data Model October 2020
"Label-block start.";
}
leaf end-label {
type rt-types:mpls-label;
must '. >= ../start-label' {
error-message
"The end-label must be greater than or equal "
+ "to start-label";
}
description
"Label-block end.";
}
leaf block-allocation-mode {
type identityref {
base label-block-alloc-mode;
}
description
"Label-block allocation mode.";
}
leaf inuse-labels-count {
when "derived-from-or-self(../block-allocation-mode, "
+ "'mpls:label-block-alloc-mode-manager')";
type yang:gauge32;
config false;
description
"Label-block inuse labels count.";
}
}
}
}
grouping rib-mpls-properties {
description
"A grouping of native MPLS RIB properties.";
leaf destination-prefix {
type leafref {
path "../mpls-local-label";
}
description
"MPLS destination prefix.";
}
leaf route-context {
type string;
description
"A context associated with the native MPLS route.";
}
}
Saad, et al. Expires April 29, 2021 [Page 16]
Internet-Draft MPLS Base YANG Data Model October 2020
grouping rib-active-route-mpls-input {
description
"A grouping applicable to native MPLS RIB 'active-route'
RPC input augmentation.";
leaf destination-address {
type leafref {
path "../mpls-local-label";
}
description
"MPLS native active route destination.";
}
leaf mpls-local-label {
type rt-types:mpls-label;
description
"MPLS local label.";
}
}
augment "/rt:routing" {
description
"MPLS augmentation.";
container mpls {
description
"MPLS container, to be used as an augmentation target node
other MPLS sub-features config, e.g. MPLS static LSP, MPLS
LDP LSPs, and Trafic Engineering MPLS LSP Tunnels, etc.";
uses globals;
uses label-blocks;
uses interfaces-mpls;
}
}
/* MPLS routes augmentation */
augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route" {
description
"This augmentation is applicable to all MPLS routes.";
leaf mpls-enabled {
type boolean;
default "false";
description
"Indicates whether MPLS is enabled for this route.";
}
leaf mpls-local-label {
when "../mpls-enabled = 'true'";
type rt-types:mpls-label;
description
"MPLS local label associated with the route.";
Saad, et al. Expires April 29, 2021 [Page 17]
Internet-Draft MPLS Base YANG Data Model October 2020
}
uses rib-mpls-properties {
/* MPLS AF augmentation to native MPLS RIB */
when "derived-from-or-self(../../rt:address-family, "
+ "'mpls:mpls')" {
description
"This augment is valid only for routes of native MPLS
RIB.";
}
}
}
/* MPLS simple-next-hop augmentation */
augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/"
+ "rt:next-hop/rt:next-hop-options/rt:simple-next-hop" {
description
"Augment 'simple-next-hop' case in IP unicast routes.";
uses nhlfe-single-contents {
when "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route"
+ "/mpls:mpls-enabled = 'true'";
}
}
/* MPLS next-hop-list augmentation */
augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/"
+ "rt:next-hop/rt:next-hop-options/rt:next-hop-list/"
+ "rt:next-hop-list/rt:next-hop" {
description
"This leaf augments the 'next-hop-list' case of IP unicast
routes.";
uses nhlfe-multiple-contents {
when "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route"
+ "/mpls:mpls-enabled = 'true'";
}
}
/* MPLS RPC input augmentation */
augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/rt:input" {
description
"Input MPLS augmentation for the 'active-route' action
statement.";
uses rib-active-route-mpls-input {
/* MPLS AF augmentation to native MPLS RIB */
when "derived-from-or-self(../rt:address-family, "
+ "'mpls:mpls')" {
Saad, et al. Expires April 29, 2021 [Page 18]
Internet-Draft MPLS Base YANG Data Model October 2020
description
"This augment is valid only for routes of native MPLS
RIB.";
}
}
}
/* MPLS RPC output augmentation */
augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
+ "rt:output/rt:route/"
+ "rt:next-hop/rt:next-hop-options/rt:simple-next-hop" {
description
"Output MPLS augmentation for the 'active-route' action
statement.";
uses nhlfe-single-contents;
}
augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
+ "rt:output/rt:route/"
+ "rt:next-hop/rt:next-hop-options/rt:next-hop-list/"
+ "rt:next-hop-list/rt:next-hop" {
description
"Output MPLS augmentation for the 'active-route' action
statement.";
uses nhlfe-multiple-contents;
}
}
<CODE ENDS>
Figure 4: MPLS base YANG module.
3. IANA Considerations
This document registers the following URIs in the 'ns' sub-registry
of the IETF XML registry [RFC3688]. Following the format in
[RFC3688], the following registration is requested to be made.
URI: urn:ietf:params:xml:ns:yang:ietf-mpls
Registrant Contact: The MPLS WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
This document registers a YANG module in the YANG Module Names
registry [RFC6020].
Saad, et al. Expires April 29, 2021 [Page 19]
Internet-Draft MPLS Base YANG Data Model October 2020
name: ietf-mpls
namespace: urn:ietf:params:xml:ns:yang:ietf-mpls
prefix: mpls
// RFC Ed.: replace XXXX with RFC number and remove this note
reference: RFCXXXX
4. Security Considerations
The YANG module specified in this document define a schema for data
that is designed to be accessed via network management protocols such
as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer
is the secure transport layer, and the mandatory-to-implement secure
transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer
is HTTPS, and the mandatory-to-implement secure transport is TLS
[RFC8446].
The NETCONF access control model [RFC8341] 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.
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:
"/rt:routing/mpls:mpls/mpls:label-blocks": there are data nodes under
this path that are writeable such as 'start-label' and 'end-label'.
Write operations to those data npdes may cause disruptive action to
existing traffic.
Some of the readable data nodes in these 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. These are the subtrees and
data nodes and their sensitivity/vulnerability:
"/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/rt:next-hop/rt:next-
hop-options/rt:next-hop-list/rt:next-hop-list/rt:next-hop" and
"/rt:routing/rt:ribs/rt:rib/rt:active-route/rt:output/rt:route/
rt:next-hop/rt:next-hop-options/rt:simple-next-hop": these two paths
are augmented by additional MPLS leaf(s) defined in this model.
Access to this information may disclose the next-hop or path per
prefix and/or other information.
Saad, et al. Expires April 29, 2021 [Page 20]
Internet-Draft MPLS Base YANG Data Model October 2020
Some of the RPC operations in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control access to these operations. These are the
operations and their sensitivity/vulnerability:
"/rt:routing/rt:ribs/rt:rib/rt:active-route/rt:input" and
"/rt:routing/rt:ribs/rt:rib/rt:active-route/rt:output/rt:route":
these two paths are augmented by additional MPLS data node(s) that
are defined in this model. Access to those path(s) may may disclose
information about per prefix route and/or other information and that
may be further used for further attack(s).
The security considerations spelled out in [RFC3031] and [RFC3032]
apply for this document as well.
5. Acknowledgement
The authors would like to thank Xia Chen for her contributions to the
early revisions of this document.
6. Appendix A. Data Tree Instance Example
A simple network setup is shown in Figure 5. R1 runs the ISIS
routing protocol, and learns reachability about two IPv4 prefixes:
P1: 198.51.100.1/32 and P2: 198.51.100.1/32, and two IPv6 prefixes
P3: 2001:db8:0:10::1/64 and P4: 2001:db8:0:10::1/64. We also assume
that R1 learns about local and remote MPLS label bindings for each
prefix using ISIS (e.g. using Segment-Routing (SR) extensions).
Saad, et al. Expires April 29, 2021 [Page 21]
Internet-Draft MPLS Base YANG Data Model October 2020
State on R1:
============
IPv4 Prefix MPLS Label
P1: 198.51.100.1/32 16001
P2: 198.51.100.2/32 16002
IPv6 Prefix MPLS Label
P3: 2001:db8:0:10::1/64 16003
P4: 2001:db8:0:10::2/64 16004
RSVP MPLS LSPv4-Tunnel:
Source: 198.51.100.3
Destination: 198.51.100.4
Tunnel-ID: 10
LSP-ID: 1
192.0.2.5/30
2001:db8:0:1::1/64
eth0
+---
/
+-----+
| R1 |
+-----+
\
+---
eth1
192.0.2.13/30
2001:db8:0:2::1/64
Figure 5: Example of network configuration.
The instance data tree could then be as follows:
{
"ietf-routing:routing":{
"ribs":{
"rib":[
{
"name":"RIB-V4",
"address-family":
"ietf-ipv4-unicast-routing:v4ur:ipv4-unicast",
"routes":{
"route":[
{
"next-hop":{
"outgoing-interface":"eth0",
"ietf-mpls:mpls-label-stack":{
Saad, et al. Expires April 29, 2021 [Page 22]
Internet-Draft MPLS Base YANG Data Model October 2020
"entry":[
{
"id":1,
"label":16001,
"ttl":255
}
]
},
"ietf-ipv4-unicast-routing:next-hop-address":
"192.0.2.5"
},
"source-protocol":"isis:isis",
"ietf-mpls:mpls-enabled":true,
"ietf-mpls:mpls-local-label":16001,
"ietf-ipv4-unicast-routing:destination-prefix":
"198.51.100.1/32",
"ietf-mpls:route-context":"SID-IDX:1"
},
{
"next-hop":{
"next-hop-list":{
"next-hop":[
{
"outgoing-interface":"eth0",
"ietf-mpls:index":"1",
"ietf-mpls:backup-index":"2",
"ietf-mpls:role":"primary-and-backup",
"ietf-mpls:mpls-label-stack":{
"entry":[
{
"id":1,
"label":16002,
"ttl":255
}
]
},
"ietf-ipv4-unicast-routing:address":"192.0.2.5"
},
{
"outgoing-interface":"eth1",
"ietf-mpls:index":"2",
"ietf-mpls:backup-index":"1",
"ietf-mpls:role":"primary-and-backup",
"ietf-mpls:mpls-label-stack":{
"entry":[
{
"id":1,
"label":16002,
Saad, et al. Expires April 29, 2021 [Page 23]
Internet-Draft MPLS Base YANG Data Model October 2020
"ttl":255
}
]
},
"ietf-ipv4-unicast-routing:address":"192.0.2.13"
}
]
}
},
"source-protocol":"isis:isis",
"ietf-mpls:mpls-enabled":true,
"ietf-mpls:mpls-local-label":16002,
"ietf-ipv4-unicast-routing:destination-prefix":
"198.51.100.2/32",
"ietf-mpls:route-context":"SID-IDX:2"
}
]
}
},
{
"name":"RIB-V6",
"address-family":
"ietf-ipv6-unicast-routing:v6ur:ipv6-unicast",
"routes":{
"route":[
{
"next-hop":{
"outgoing-interface":"eth0",
"ietf-mpls:mpls-label-stack":{
"entry":[
{
"id":1,
"label":16003,
"ttl":255
}
]
},
"ietf-ipv6-unicast-routing:next-hop-address":
"2001:db8:0:1::1"
},
"source-protocol":"isis:isis",
"ietf-mpls:mpls-enabled":true,
"ietf-mpls:mpls-local-label":16001,
"ietf-ipv6-unicast-routing:destination-prefix":
"2001:db8:0:10::1/6",
"ietf-mpls:route-context":"SID-IDX:1"
},
{
Saad, et al. Expires April 29, 2021 [Page 24]
Internet-Draft MPLS Base YANG Data Model October 2020
"next-hop":{
"next-hop-list":{
"next-hop":[
{
"outgoing-interface":"eth0",
"ietf-mpls:index":"1",
"ietf-mpls:backup-index":"2",
"ietf-mpls:role":"primary-and-backup",
"ietf-mpls:mpls-label-stack":{
"entry":[
{
"id":1,
"label":16004,
"ttl":255
}
]
},
"ietf-ipv6-unicast-routing:address":
"2001:db8:0:1::1"
},
{
"outgoing-interface":"eth1",
"ietf-mpls:index":"2",
"ietf-mpls:backup-index":"1",
"ietf-mpls:role":"primary-and-backup",
"ietf-mpls:mpls-label-stack":{
"entry":[
{
"id":1,
"label":16004,
"ttl":255
}
]
},
"ietf-ipv6-unicast-routing:address":
"2001:db8:0:2::1"
}
]
}
},
"source-protocol":"isis:isis",
"ietf-mpls:mpls-enabled":true,
"ietf-mpls:mpls-local-label":16004,
"ietf-ipv6-unicast-routing:destination-prefix":
"2001:db8:0:10::2/64",
"ietf-mpls:route-context":"SID-IDX:2"
}
]
Saad, et al. Expires April 29, 2021 [Page 25]
Internet-Draft MPLS Base YANG Data Model October 2020
}
},
{
"name":"RIB-MPLS",
"address-family":"ietf-mpls:mpls:mpls",
"routes":{
"route":[
{
"next-hop":{
"outgoing-interface":"eth0",
"ietf-mpls:mpls-label-stack":{
"entry":[
{
"id":1,
"label":24002,
"ttl":255
}
]
},
"ietf-ipv4-unicast-routing:next-hop-address":
"192.0.2.5"
},
"source-protocol":"rsvp:rsvp",
"ietf-mpls:mpls-enabled":true,
"ietf-mpls:mpls-local-label":24001,
"ietf-mpls:destination-prefix":"24001",
"ietf-mpls:route-context":
"RSVP Src:198.51.100.3,Dst:198.51.100.4,T:10,L:1"
}
}
}
}
]
},
"ietf-mpls:mpls":{
"mpls-label-blocks":{
"mpls-label-block":[
{
"index":"mpls-srgb-label-block",
"start-label":16000,
"end-label":16500,
"block-allocation-mode":"mpls:label-block-alloc-mode-manager"
}
]
},
"interfaces":{
"interface":[
{
Saad, et al. Expires April 29, 2021 [Page 26]
Internet-Draft MPLS Base YANG Data Model October 2020
"name":"eth0",
"mpls-enabled":true,
"maximum-labeled-packet":1488
},
{
"name":"eth1",
"mpls-enabled":true,
"maximum-labeled-packet":1488
}
]
}
}
}
}
Figure 6: Foo bar.
7. Contributors
Igor Bryskin
Huawei Technologies
email: i_bryskin@yahoo.com
Himanshu Shah
Ciena
email: hshah@ciena.com
8. References
8.1. Normative References
[RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001,
<https://www.rfc-editor.org/info/rfc3032>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
Saad, et al. Expires April 29, 2021 [Page 27]
Internet-Draft MPLS Base YANG Data Model October 2020
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger,
"Common YANG Data Types for the Routing Area", RFC 8294,
DOI 10.17487/RFC8294, December 2017,
<https://www.rfc-editor.org/info/rfc8294>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[RFC8343] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
<https://www.rfc-editor.org/info/rfc8343>.
[RFC8349] Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for
Routing Management (NMDA Version)", RFC 8349,
DOI 10.17487/RFC8349, March 2018,
<https://www.rfc-editor.org/info/rfc8349>.
Saad, et al. Expires April 29, 2021 [Page 28]
Internet-Draft MPLS Base YANG Data Model October 2020
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
8.2. Informative References
[RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
Label Switching Architecture", RFC 3031,
DOI 10.17487/RFC3031, January 2001,
<https://www.rfc-editor.org/info/rfc3031>.
[RFC7424] Krishnan, R., Yong, L., Ghanwani, A., So, N., and B.
Khasnabish, "Mechanisms for Optimizing Link Aggregation
Group (LAG) and Equal-Cost Multipath (ECMP) Component Link
Utilization in Networks", RFC 7424, DOI 10.17487/RFC7424,
January 2015, <https://www.rfc-editor.org/info/rfc7424>.
Authors' Addresses
Tarek Saad
Juniper Networks
Email: tsaad@juniper.net
Kamran Raza
Cisco Systems Inc
Email: skraza@cisco.com
Rakesh Gandhi
Cisco Systems Inc
Email: rgandhi@cisco.com
Xufeng Liu
Volta Networks
Email: xufeng.liu.ietf@gmail.com
Saad, et al. Expires April 29, 2021 [Page 29]
Internet-Draft MPLS Base YANG Data Model October 2020
Vishnu Pavan Beeram
Juniper Networks
Email: vbeeram@juniper.net
Saad, et al. Expires April 29, 2021 [Page 30]
