Internet DRAFT - draft-ietf-lsr-yang-isis-reverse-metric
draft-ietf-lsr-yang-isis-reverse-metric
Network Working Group C. Hopps
Internet-Draft LabN Consulting, L.L.C.
Intended status: Standards Track 1 January 2022
Expires: 5 July 2022
YANG Module for IS-IS Reverse Metric
draft-ietf-lsr-yang-isis-reverse-metric-06
Abstract
This document defines a YANG module for managing the reverse metric
extension to the Intermediate System to Intermediate System intra-
domain routeing information exchange protocol (IS-IS).
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 5 July 2022.
Copyright Notice
Copyright (c) 2022 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
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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. YANG Management . . . . . . . . . . . . . . . . . . . . . . . 2
2.1. YANG Tree . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
3.1. Updates to the IETF XML Registry . . . . . . . . . . . . 8
3.2. Updates to the YANG Module Names Registry . . . . . . . . 8
4. Security Considerations . . . . . . . . . . . . . . . . . . . 9
5. Normative References . . . . . . . . . . . . . . . . . . . . 10
6. Informative References . . . . . . . . . . . . . . . . . . . 11
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 12
A.1. Enablement Example using XML YANG Instance Data . . . . . 12
A.2. Usage Example using XML YANG Instance Data . . . . . . . 13
A.3. Usage Example using JSON YANG Instance Data . . . . . . . 14
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
This document defines a YANG module for managing the reverse metric
extension to IS-IS [RFC8500], [ISO10589]. Please refer to [RFC8500]
for the description and definition of the functionality managed by
this module.
The YANG data model described in this document conforms to the
Network Management Datastore Architecture defined in [RFC8342].
2. YANG Management
2.1. YANG Tree
The following is the YANG tree diagram ([RFC8340]) for the IS-IS
reverse metric extension additions.
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module: ietf-isis-reverse-metric
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis:
+--rw reverse-metric
+--rw enable-receive? boolean
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis/isis:interfaces
/isis:interface:
+--rw reverse-metric
+--rw metric? isis:wide-metric
+--rw flags
| +--rw whole-lan? boolean
| +--rw allow-unreachable? boolean
+--rw exclude-te-metric? boolean
+--rw level-1
| +--rw metric? isis:wide-metric
| +--rw flags
| | +--rw whole-lan? boolean
| | +--rw allow-unreachable? boolean
| +--rw exclude-te-metric? boolean
+--rw level-2
+--rw metric? isis:wide-metric
+--rw flags
| +--rw whole-lan? boolean
| +--rw allow-unreachable? boolean
+--rw exclude-te-metric? boolean
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/isis:isis/isis:interfaces
/isis:interface/isis:adjacencies/isis:adjacency:
+--ro reverse-metric
+--ro metric? isis:wide-metric
+--ro flags
| +--ro whole-lan? boolean
| +--ro allow-unreachable? boolean
+--ro te-metric? uint32
2.2. YANG Module
The following is the YANG module for managing the IS-IS reverse
metric functionality defined in [RFC8500]. It imports modules from
the following RFCs: [RFC8349], [I-D.ietf-isis-yang-isis-cfg].
This YANG module uses the same "Per-Level" hierarchical configuration
structure as is defined in the augmented base module.
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<CODE BEGINS> file "ietf-isis-reverse-metric@2022-01-01.yang"
module ietf-isis-reverse-metric {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric";
prefix isis-rmetric;
import ietf-routing {
prefix rt;
reference
"RFC8349:
A YANG Data Model for Routing Management (NMDA Version)";
}
import ietf-isis {
prefix isis;
reference
"draft-ietf-isis-yang-isis-cfg-42:
YANG Data Model for IS-IS Protocol";
}
organization
"IETF LSR Working Group (LSR)";
contact
"WG Web: <https://datatracker.ietf.org/wg/lsr/>
WG List: <mailto:lsr@ietf.org>
Author: Christian Hopps
<mailto:chopps@chopps.org>";
// RFC Ed.: replace XXXX with actual RFC number and
// remove this note.
description
"This module defines the configuration and operational state for
managing the IS-IS reverse metric functionality [RFC8500].
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 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
(https://www.rfc-editor.org/info/rfcXXXX>); see the RFC itself
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for full legal notices.";
revision 2022-01-01 {
description "Initial Revision";
reference "RFC XXXX: YANG IS-IS Reverse Metric";
}
grouping reverse-metric-data {
description "IS-IS reverse metric data.";
leaf metric {
type isis:wide-metric;
description "The reverse metric value.";
reference "RFC8500, Section 2";
}
container flags {
description "The reverse metric flag values.";
leaf whole-lan {
type boolean;
description
"The 'whole LAN' or W-bit. If true then a DIS processing
this reverse metric will add the metric value to all the
nodes it advertises in the pseudo-node LSP for this
interface. Otherwise, it will only increment the metric
for the advertising node in the pseudo-node LSP for this
interface.";
reference "RFC8500, Section 2";
}
leaf allow-unreachable {
type boolean;
description
"The 'allow-unreachable' or U-bit. If true it allows the
neighbor to increment the overall metric up to 2^24-1
rather than the lesser maximum of 2^24-2. If the metric
is then set by the neighbor to 2^24-1, it will cause
traffic to stop using, rather than avoid using, the
interface.";
reference "RFC8500, Section 2";
}
}
}
grouping reverse-metric-if-config-data {
description "IS-IS reverse metric config data.";
uses reverse-metric-data;
leaf exclude-te-metric {
type boolean;
default false;
description
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"If true and there is a TE metric defined for this
interface then do not send the TE metric sub-TLV in the
reverse metric TLV.";
reference "RFC8500, Section 2";
}
}
grouping tlv16-reverse-metric {
description "IS-IS reverse metric TLV data.";
uses reverse-metric-data;
leaf te-metric {
type uint32;
description
"The TE metric value from the sub-TLV if present.";
reference "RFC8500, Section 2";
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+"rt:control-plane-protocol/"
+"isis:isis" {
when "derived-from-or-self(../rt:type, 'isis:isis')" {
description
"This augment is only valid when routing protocol instance
type is 'isis'.";
}
description
"The reverse metric configuration for an IS-IS instance.";
container reverse-metric {
description "Global reverse metric configuration.";
leaf enable-receive {
type boolean;
default false;
description
"Enable handling of reverse metric announcements from
neighbors. By default, reverse metric handling is disabled
and must be explicitly enabled through this
configuration.";
}
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+"rt:control-plane-protocol/"
+"isis:isis/isis:interfaces/isis:interface" {
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when "derived-from-or-self(../../../rt:type, 'isis:isis')" {
description
"This augment is only valid when routing protocol instance
type is 'isis'.";
}
description
"The reverse metric configuration for an interface.";
container reverse-metric {
description
"Announce a reverse metric to neighbors. The configuration
is hierarchical and follows the same behavior as defined
for 'Per-Level' values in the augmented base module.
Reverse metric operation is enabled by the configuration of
a reverse-metric metric value at either the top level or
under a level-specific container node. If a reverse-metric
metric value is only specified under a level-specific
container node then operation is only enabled at the
specified level.
As the reverse metric is advertised in IIH PDUs, level
specific configuration is only available for broadcast
interface types";
uses reverse-metric-if-config-data {
refine "flags/whole-lan" {
default false;
}
refine "flags/allow-unreachable" {
default false;
}
}
container level-1 {
when '../../isis:interface-type = "broadcast"';
description
"Announce a reverse metric to level-1 neighbors.";
uses reverse-metric-if-config-data;
}
container level-2 {
when '../../isis:interface-type = "broadcast"';
description
"Announce a reverse metric to level-2 neighbors.";
uses reverse-metric-if-config-data;
}
}
}
augment "/rt:routing/rt:control-plane-protocols/"
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+"rt:control-plane-protocol/"
+"isis:isis/isis:interfaces/isis:interface/"
+"isis:adjacencies/isis:adjacency" {
when "derived-from-or-self(../../../../../rt:type,
'isis:isis')" {
description
"This augment is only valid when routing protocol instance
type is 'isis'";
}
description
"The reverse metric state advertised by an adjacency.";
container reverse-metric {
description "IS-IS reverse metric TLV data.";
uses tlv16-reverse-metric;
}
}
}
<CODE ENDS>
3. IANA Considerations
3.1. Updates to the IETF XML Registry
This document registers a URI in the "IETF XML Registry" [RFC3688].
Following the format in [RFC3688], the following registration has
been made:
URI urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric
Registrant Contact The IESG.
XML N/A; the requested URI is an XML namespace.
3.2. Updates to the YANG Module Names Registry
This document registers one YANG module in the "YANG Module Names"
registry [RFC6020]. Following the format in [RFC6020], the following
registration has been made:
name ietf-isis-reverse-metric
namespace urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric
prefix isis-rmetric
reference RFC XXXX (RFC Ed.: replace XXX with actual RFC number and
remove this note.)
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4. 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 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.
The YANG module defined in this document can enable, disable and
modify the behavior of metrics used by routing. For the security
implications regarding these types of changes consult [RFC8500] which
defines the functionality as well as [I-D.ietf-isis-yang-isis-cfg].
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 YANG nodes correspond directly
to the RFC 8500 functionality and the security considerations of the
functionality are described in RFC 8500.
These are the subtrees and data nodes:
Under "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/isis:isis"
- /isis-rmetric:reverse-metric/isis-rmetric:enable-receive
Under "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/isis:isis/" +
"isis:interfaces/isis:interface/" +
"isis-rmetric:reverse-metric"
- /isis-rmetric:metric
- /isis-rmetric:flags/isis-rmetric:whole-lan
- /isis-rmetric:flags/isis-rmetric:allow-unreachable
- /isis-rmetric:exclude-te-metric
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Under "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/isis:isis/" +
"isis:interfaces/isis:interface/" +
"isis-rmetric:reverse-metric/" +
"isis-rmetric:level-1/"
- /isis-rmetric:metric
- /isis-rmetric:flags/isis-rmetric:whole-lan
- /isis-rmetric:flags/isis-rmetric:allow-unreachable
- /isis-rmetric:exclude-te-metric
Under "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/isis:isis/" +
"isis:interfaces/isis:interface/" +
"isis-rmetric:reverse-metric/" +
"isis-rmetric:level-2/"
- /isis-rmetric:metric
- /isis-rmetric:flags/isis-rmetric:whole-lan
- /isis-rmetric:flags/isis-rmetric:allow-unreachable
- /isis-rmetric:exclude-te-metric
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. These YANG nodes correspond
directly to the RFC 8500 functionality and the security
considerations of the functionality are described in RFC 8500. These
are the subtrees and data nodes:
Under "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/isis:isis/" +
"isis:interfaces/isis:interface/" +
"isis:adjacencies/isis:adjacency/" +
"isis-rmetric:reverse-metric"
- /isis-rmetric:metric
- /isis-rmetric:flags/isis-rmetric:whole-lan
- /isis-rmetric:flags/isis-rmetric:allow-unreachable
- /isis-rmetric:te-metric
5. Normative References
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[ISO10589] International Organization for Standardization,
"Intermediate System to Intermediate System intra-domain
routeing information exchange protocol for use in
conjunction with the protocol for providing the
connectionless-mode network service (ISO 8473)", ISO
Standard 10589:2002, 2002.
[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>.
[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>.
[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>.
[RFC8500] Shen, N., Amante, S., and M. Abrahamsson, "IS-IS Routing
with Reverse Metric", RFC 8500, DOI 10.17487/RFC8500,
February 2019, <https://www.rfc-editor.org/info/rfc8500>.
[I-D.ietf-isis-yang-isis-cfg]
Litkowski, S., Yeung, D., Lindem, A., Zhang, J., and L.
Lhotka, "YANG Data Model for IS-IS Protocol", Work in
Progress, Internet-Draft, draft-ietf-isis-yang-isis-cfg-
42, 15 October 2019,
<https://datatracker.ietf.org/doc/html/draft-ietf-isis-
yang-isis-cfg-42>.
6. Informative References
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[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>.
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/info/rfc7951>.
[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>.
[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>.
[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>.
Appendix A. Examples
A.1. Enablement Example using XML YANG Instance Data
Below is an example of XML YANG instance data [RFC8342] to enable
reverse metric processing.
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<rt:routing
xmlns:rt="urn:ietf:params:xml:ns:yang:ietf-routing"
xmlns:isis="urn:ietf:params:xml:ns:yang:ietf-isis"
xmlns:isis-rmetric=
"urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric">
<rt:control-plane-protocols>
<rt:control-plane-protocol>
<rt:type>isis:isis</rt:type>
<rt:name>default</rt:name>
<isis:isis>
<isis:area-address>00</isis:area-address>
<isis-rmetric:reverse-metric>
<isis-rmetric:enable-receive>true</isis-rmetric:enable-receive>
</isis-rmetric:reverse-metric>
</isis:isis>
</rt:control-plane-protocol>
</rt:control-plane-protocols>
</rt:routing>
Figure 1: Example XML data to enable reverse metric processing.
A.2. Usage Example using XML YANG Instance Data
Below is an example of XML YANG instance data [RFC8342] for the ietf-
isis-reverse-metric module.
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<if:interfaces
xmlns:if="urn:ietf:params:xml:ns:yang:ietf-interfaces"
xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">
<if:interface>
<if:name>eth0</if:name>
<if:type>ianaift:ethernetCsmacd</if:type>
</if:interface>
</if:interfaces>
<rt:routing
xmlns:rt="urn:ietf:params:xml:ns:yang:ietf-routing"
xmlns:isis="urn:ietf:params:xml:ns:yang:ietf-isis"
xmlns:isis-rmetric=
"urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric">
<rt:control-plane-protocols>
<rt:control-plane-protocol>
<rt:type>isis:isis</rt:type>
<rt:name>default</rt:name>
<isis:isis>
<isis:area-address>00</isis:area-address>
<isis:interfaces>
<isis:interface>
<isis:name>eth0</isis:name>
<isis-rmetric:reverse-metric>
<isis-rmetric:metric>
65535
</isis-rmetric:metric>
</isis-rmetric:reverse-metric>
</isis:interface>
</isis:interfaces>
</isis:isis>
</rt:control-plane-protocol>
</rt:control-plane-protocols>
</rt:routing>
Figure 2: Example XML data for ietf-isis-reverse-metric module.
A.3. Usage Example using JSON YANG Instance Data
Below is an example of JSON YANG instance data [RFC7951] for the
ietf-isis-reverse-metric module.
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{
"ietf-interfaces:interfaces": {
"interface": [
{
"name": "eth0",
"type": "iana-if-type:ethernetCsmacd"
}
]
},
"ietf-routing:routing": {
"control-plane-protocols": {
"control-plane-protocol": [
{
"type": "ietf-isis:isis",
"name": "default",
"ietf-isis:isis": {
"area-address": [
"00"
],
"interfaces": {
"interface": [
{
"name": "eth0",
"ietf-isis-reverse-metric:reverse-metric": {
"level-1": {
"metric": 65535,
"exclude-te-metric": true
}
}
}
]
}
}
}
]
}
}
}
Figure 3: Example JSON data for level-1 only reverse metric.
Author's Address
Christian Hopps
LabN Consulting, L.L.C.
Email: chopps@chopps.org
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