Internet DRAFT - draft-ogondio-opsawg-ospf-topology
draft-ogondio-opsawg-ospf-topology
opsawg O. G. D. Dios
Internet-Draft Telefonica
Intended status: Standards Track S. B. Giraldo
Expires: 25 April 2024 V. Lopez
Nokia
23 October 2023
A YANG Data Model for Open Shortest Path First (OSPF) Topology
draft-ogondio-opsawg-ospf-topology-01
Abstract
This document defines a YANG data model for representing an
abstracted view of a network topology that contains Open Shortest
Path First (OSPF) information. This document augments the 'ietf-
network' data model by adding OSPF concepts and explains how the data
model can be used to represent the OSPF topology.
The YANG data model defined in this document conforms to the Network
Management Datastore Architecture (NMDA).
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 25 April 2024.
Copyright Notice
Copyright (c) 2023 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 (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
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and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology and Notations . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.3. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3
1.4. Prefix in Data Node Names . . . . . . . . . . . . . . . . 3
2. YANG Data Model for OSPF Topology . . . . . . . . . . . . . . 4
3. OSPF Topology Tree Diagram . . . . . . . . . . . . . . . . . 5
4. YANG Model for OSPF topology . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
7. Implementation Status . . . . . . . . . . . . . . . . . . . . 12
8. Normative References . . . . . . . . . . . . . . . . . . . . 12
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
Topology collection is a critical use case for network operators
because the network topology is an abstract representation of the
physical nodes, links, and network interconnections. Network
planning processes require that network resources are placed to meet
traffic demand requirements not just in terms of bandwidth or delay,
but also for failure scenarios. Network operators perform the
network planning process as an offline process, which obtains
information not directly from the network, but from inventory or
template information. The main reason for this process was the lack
of dynamic and programmatic interfaces that can allow planning tools
to obtain such information.
Thanks to the definition of the ietf-network model in [RFC8345] this
situation has changed, because network operators can use an API with
dynamic topological information. On top of the work in [RFC8345],
[RFC8346] and [RFC8944] extends the generic network and network
topology data models with topology attributes that are specific to
Layer 3 and Layer 2. However, there is not any model that exposes
Open Shortest Path First (OSPF) information. This information is
required in the IP/MPLS planning process to properly assess the
required network resources to meet the traffic demands in normal and
failure scenarios.
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The main objective of this model is to represent most relevant OSPF
topology attributes.
This document defines a YANG data model for representing, managing,
and controlling the OSPF topology. The data model augments ietf-
network module [RFC8345] by adding the OSPF information.
This document explains the scope and purpose of the OSPF topology
model and how the topology and service models fit together.
The YANG data model defined in this document conforms to the Network
Management Datastore Architecture [RFC8342].
1.1. Terminology and Notations
This document assumes that the reader is familiar with OSPF and the
contents of [RFC8345]. The document uses terms from those documents.
The terminology for describing YANG data models is found in
[RFC7950], [RFC8795] and [RFC8346].
1.2. Requirements Language
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
[RFC2119], [RFC8174] when, and only when, they appear in all
capitals, as shown here.
1.3. Tree Diagram
Authors include a simplified graphical representation of the data
model is used in Section 3 of this document. The meaning of the
symbols in these diagrams is defined in [RFC8340].
1.4. Prefix in Data Node Names
In this document, names of data nodes and other data model objects
are prefixed using the standard prefix associated with the
corresponding YANG imported modules, as shown in the following table.
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+========+=======================+===========+
| Prefix | Yang Module | Reference |
+========+=======================+===========+
| ospfnt | ietf-l3-ospf-topology | RFCXXX |
+--------+-----------------------+-----------+
| yang | ietf-yang-types | [RFC6991] |
+--------+-----------------------+-----------+
Table 1: Prefixes and corresponding YANG
modules
RFC Editor Note: Please replace XXXX with the RFC number assigned to
this document. Please remove this note.
2. YANG Data Model for OSPF Topology
The abstract (base) network data model is defined in the "ietf-
network" module of [RFC8345]. The OSPF-topology builds on the
network data model defined in the "ietf-network" module [RFC8345],
augmenting the nodes with OSPF information, which anchor the links
and are contained in nodes.
There is a set of parameters and augmentations that are included at
the node level. Each parameter and description are detailed
following:
* Network-types: Its presence identifies the OSPF topology type.
Thus, the network type MUST be ospf-topology.
* OSPF timer attributes: Identifies the node timer attributes
configured in the network element. They are wait timer, rapid
delay, slow delay, and the timer type (linear or exponential back-
off).
* OSPF status: contains the neighbours' information.
A second set of parameters, along with augmentations, is included at
the link and termination point level. Each parameter is listed as
follows:
* Interface-type
* Area ID
* Metric
* Passive mode
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3. OSPF Topology Tree Diagram
Figure 1 below shows the tree diagram of the YANG data model defined
in module ietf-l3-ospf-topology.yang (Section 4).
module: ietf-l3-ospf-topology
augment /nw:networks/nw:network/nw:network-types:
+--rw ospfv2-topology!
augment /nw:networks/nw:network/nw:node/
l3t:l3-node-attributes:
+--rw ospf-timer-attributes
+--rw wait-timer? uint32
+--rw rapid-delay? uint32
+--rw slow-delay? uint32
+--rw timer-type? enumeration
augment /nw:networks/nw:network/nt:link/
l3t:l3-link-attributes:
+--rw ospfv2-termination-point-attributes
+--rw interface-type? identityref
+--rw area-id? area-id-type
+--rw metric? uint64
+--rw is-passive? boolean
augment /nw:networks/nw:network/nw:node/nt:termination-point/
l3t:l3-termination-point-attributes:
+--rw ospfv2-termination-point-attributes
+--rw interface-type? identityref
+--rw area-id? area-id-type
+--rw metric? uint64
+--rw is-passive? boolean
Figure 1: OSPF Topology tree diagram
4. YANG Model for OSPF topology
Following the YANG model is presented.
<CODE BEGINS> file "ietf-l3-ospf-topology@2023-10-23.yang"
module ietf-l3-ospf-topology {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-l3-ospf-topology";
prefix "ospfnt";
import ietf-yang-types {
prefix "yang";
}
import ietf-network {
prefix "nw";
}
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import ietf-network-topology {
prefix "nt";
}
import ietf-l3-unicast-topology {
prefix "l3t";
}
organization
"IETF OPSA (Operations and Management Area) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/opsawg/>
WG List: <mailto:opsawg@ietf.org>
Editor: Oscar Gonzalez de Dios
<mailto:oscar.gonzalezdedios@telefonica.com>
Editor: Samier Barguil
<mailto:samier.barguilgiraldo.ext@telefonica.com>
Editor: Victor Lopez
<mailto:victor.lopez@nokia.com>";
description
"This module defines a model for Layer 3 OSPF
topologies.
Copyright (c) 2022 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 Revised 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
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
for full legal notices.";
revision 2022-03-07 {
description
"Initial version";
reference
"RFC XXXX: A YANG Data Model for Open Shortest Path First
(OSPF) Topology"; }
typedef area-id-type {
type yang:dotted-quad;
description
"An identifier for the OSPFv2 area.";
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reference
"RFC 2328: OSPF Version 2";
}
identity inf-type {
description
"Identity for the OSPF interface type.";
reference
"RFC 2328: OSPF Version 2";
}
identity nbma {
base inf-type;
description
"Identity for the NBMA interface.";
reference
"RFC 2328: OSPF Version 2";
}
identity p2mp {
base inf-type;
description
"Identity for the p2mp interface.";
reference
"RFC 2328: OSPF Version 2";
}
identity p2mp-over-lan {
base inf-type;
description
"Identity for the p2mp-over-lan interface.";
reference
"RFC 2328: OSPF Version 2";
}
identity p2p {
base inf-type;
description
"Identity for the p2p interface.";
reference
"RFC 2328: OSPF Version 2";
}
grouping ospfv2-topology-type {
description "Identifies the topology type to be OSPF v2.";
container ospfv2-topology {
presence "indicates OSPF v2 topology";
description
"The presence of the container node indicates OSPF v2
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topology";
}
}
grouping ospfv2-node-attributes {
description "OSPF v2 node scope attributes";
container ospf-timer-attributes {
description
"Contains OSPFv2 node timer attributes";
leaf wait-timer {
type uint32;
units msec;
description
"The amount of time to wait without detecting SPF
trigger events before going back to the rapid delay.";
reference
"RFC 8541: SPF Impact on IGP Micro-loops";
}
leaf rapid-delay {
type uint32;
units msec;
description
"The amount of time to wait before running SPF after
the initial SPF trigger event.";
reference
"RFC 8541: SPF Impact on IGP Micro-loops";
}
leaf slow-delay {
type uint32;
units msec;
description
"The amount of time to wait before running an SPF.";
reference
"RFC 8541: SPF Impact on IGP Micro-loops";
}
leaf timer-type {
type enumeration {
enum LINEAR_BACKOFF {
description
"The link state routing protocol uses linear
back-off.";
}
enum EXPONENTIAL_BACKOFF {
description
"The link state routing protocol uses exponential
back-off.";
}
}
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description
"The timer mode that is utilised by the SPF algorithm.";
reference
"RFC 8541: SPF Impact on IGP Micro-loops";
}
}
}
grouping ospfv2-termination-point-attributes {
description "OSPF termination point scope attributes";
container ospfv2-termination-point-attributes {
description
"Indicates the termination point from the
which the OSPF is configured. A termination
point can be a physical port, an interface, etc.";
leaf interface-type {
type identityref {
base inf-type ;
}
description
"OSPF interface type.";
reference
"RFC 2328: OSPF Version 2";
}
leaf area-id {
type area-id-type;
description
"An identifier for the OSPFv2 area.";
reference
"RFC 2328: OSPF Version 2";
}
leaf metric {
type uint64;
description
"OSFP Protocol metric";
reference
"RFC 2328: OSPF Version 2";
}
leaf is-passive{
type boolean;
description
"Interface passive mode";
reference
"RFC 2328: OSPF Version 2";
}
}
}
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augment "/nw:networks/nw:network/nw:network-types" {
description
"Introduces new network type for L3 Unicast topology";
uses ospfv2-topology-type;
}
augment "/nw:networks/nw:network/nw:node/"
+"l3t:l3-node-attributes" {
when
"/nw:networks/nw:network/nw:network-types/"
+"ospfnt:ospfv2-topology" {
description
"Augmentation parameters apply only for networks with
OSPF topology";
}
description
"OSPF node-level attributes ";
uses ospfv2-node-attributes;
}
augment "/nw:networks/nw:network/"
+ "nt:link/l3t:l3-link-attributes" {
when "/nw:networks/nw:network/nw:network-types/"
+"ospfnt:ospfv2-topology" {
description
"Augmentation parameters apply only for networks with
OSFP topology";
}
description "Augments topology link configuration";
uses ospfv2-termination-point-attributes;
}
augment "/nw:networks/nw:network/nw:node/"
+"nt:termination-point/l3t:l3-termination-point-attributes" {
when "/nw:networks/nw:network/nw:network-types/"
+"ospfnt:ospfv2-topology" {
description
"Augmentation parameters apply only for networks with
OSFP topology";
}
description "Augments topology termination point configuration";
uses ospfv2-termination-point-attributes;
}
}
<CODE ENDS>
Figure 2: OSPF Topology YANG module
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5. Security Considerations
The YANG module specified in this document defines 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 Network Configuration Access Control Model (NACM) [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.
6. IANA Considerations
This document registers the following namespace URIs in the IETF XML
registry [RFC3688]:
--------------------------------------------------------------------
URI: urn:ietf:params:xml:ns:yang:ietf-l3-ospf-topology
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
--------------------------------------------------------------------
This document registers the following YANG module in the YANG Module
Names registry [RFC6020]:
--------------------------------------------------------------------
name: ietf-l3-ospf-topology
namespace: urn:ietf:params:xml:ns:yang:ietf-l3-ospf-topology
maintained by IANA: N
prefix: ietf-l3-ospf-topology
reference: RFC XXXX
--------------------------------------------------------------------
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7. Implementation Status
This section will be used to track the status of the implementations
of the model. It is aimed at being removed if the document becomes
RFC.
8. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/rfc/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/rfc/rfc6020>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/rfc/rfc6242>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/rfc/rfc6991>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/rfc/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/rfc/rfc8040>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[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/rfc/rfc8340>.
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[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/rfc/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/rfc/rfc8342>.
[RFC8345] Clemm, A., Medved, J., Varga, R., Bahadur, N.,
Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
2018, <https://www.rfc-editor.org/rfc/rfc8345>.
[RFC8346] Clemm, A., Medved, J., Varga, R., Liu, X.,
Ananthakrishnan, H., and N. Bahadur, "A YANG Data Model
for Layer 3 Topologies", RFC 8346, DOI 10.17487/RFC8346,
March 2018, <https://www.rfc-editor.org/rfc/rfc8346>.
[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/rfc/rfc8446>.
[RFC8795] Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
O. Gonzalez de Dios, "YANG Data Model for Traffic
Engineering (TE) Topologies", RFC 8795,
DOI 10.17487/RFC8795, August 2020,
<https://www.rfc-editor.org/rfc/rfc8795>.
[RFC8944] Dong, J., Wei, X., Wu, Q., Boucadair, M., and A. Liu, "A
YANG Data Model for Layer 2 Network Topologies", RFC 8944,
DOI 10.17487/RFC8944, November 2020,
<https://www.rfc-editor.org/rfc/rfc8944>.
Acknowledgments
This work is partially supported by the European Commission under
Horizon 2020 Secured autonomic traffic management for a Tera of SDN
flows (Teraflow) project (grant agreement number 101015857).
Authors' Addresses
Oscar González de Dios
Telefonica
Email: oscar.gonzalezdedios@telefonica.com
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Samier Barguil Giraldo
Nokia
Email: samier.barguil_giraldo@nokia.com
Victor Lopez
Nokia
Email: victor.lopez@nokia.com
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