RFC 8533 PROPOSED STANDARD YANG · OAM · NETWORK MANAGEMENT
OAM Retrieval YANG: A YANG Data Model for Retrieval Methods for the Management of Operations, Administration, and Maintenance (OAM) Protocols That Use Connectionless Communications
Two on-demand YANG commands, continuity check and path discovery, for ping-and-traceroute style tools on connectionless networks.
RFC EDITOR
Kumar, D., Wang, M., Wu, Q., Ed., Rahman, R., and S. Raghavan, "A YANG Data Model for Retrieval Methods for the Management of Operations, Administration, and Maintenance (OAM) Protocols That Use Connectionless Communications", RFC 8533, DOI 10.17487/RFC8533, April 2019, <https://www.rfc-editor.org/info/rfc8533>.
BIBTEX
@misc{rfc8533,
series = {Request for Comments},
number = 8533,
howpublished = {RFC 8533},
publisher = {RFC Editor},
doi = {10.17487/RFC8533},
url = {https://www.rfc-editor.org/info/rfc8533},
author = {D. Kumar and M. Wang and Q. Wu and R. Rahman and S. Raghavan},
title = {{A YANG Data Model for Retrieval Methods for the Management of Operations, Administration, and Maintenance (OAM) Protocols That Use Connectionless Communications}},
pagetotal = 41,
year = 2019,
month = apr,
} RFC text
Contents
Internet Engineering Task Force (IETF) D. Kumar
Request for Comments: 8533 Cisco
Category: Standards Track M. Wang
ISSN: 2070-1721 Q. Wu, Ed.
Huawei
R. Rahman
S. Raghavan
Cisco
April 2019
A YANG Data Model for Retrieval Methods for the Management of
Operations, Administration, and Maintenance (OAM) Protocols
That Use Connectionless Communications
Abstract
This document presents a retrieval method YANG data model for
connectionless Operations, Administration, and Maintenance (OAM)
protocols. It provides technology-independent RPC operations for OAM
protocols that use connectionless communication. The retrieval
methods model herein presented can be extended to include technology-
specific details. There are two key benefits of this approach:
First, it leads to uniformity between OAM protocols. Second, it
supports both nested OAM workflows (i.e., performing OAM functions at
different or the same levels through a unified interface) as well as
interactive OAM workflows (i.e., performing OAM functions at the same
levels through a unified interface).
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
https://www.rfc-editor.org/info/rfc8533.
Copyright Notice
Copyright (c) 2019 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 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 . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This document . . . . . . . . . . . . . . 3
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 4
3. Overview of the Connectionless OAM Retrieval Methods Model . 4
3.1. RPC Operation Definitions . . . . . . . . . . . . . . . . 4
3.2. OAM Retrieval Methods Hierarchy . . . . . . . . . . . . . 7
4. OAM Retrieval Methods YANG Module . . . . . . . . . . . . . . 16
5. Security Considerations . . . . . . . . . . . . . . . . . . . 26
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.1. Normative References . . . . . . . . . . . . . . . . . . 27
7.2. Informative References . . . . . . . . . . . . . . . . . 28
Appendix A. Extending Connectionless OAM Method Module Example . 29
A.1. Example of New Retrieval Procedures Model . . . . . . . . 29
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 40
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 41
1. Introduction
Operations, Administration, and Maintenance (OAM) are important
networking functions that allow operators to:
1. monitor network communications (i.e., reachability verification
and Continuity Check)
2. troubleshoot failures (i.e., fault verification and localization)
3. monitor service-level agreements and performance (i.e.,
performance management)
An overview of OAM tools is presented in [RFC7276].
Ping and Traceroute [RFC4443], as well as Bidirectional Forwarding
Detection (BFD) [RFC5880], are well-known fault verification and
isolation tools, respectively, for IP networks [RFC792]. Over the
years, different technologies have developed similar toolsets for
equivalent purposes.
This document presents an on-demand retrieval method YANG data model
for OAM protocols that use connectionless communication. This model
provides technology-independent RPC operations for OAM protocols that
use connectionless communication (i.e., connectionless OAM). It is
separated from the generic YANG data model for connectionless OAM
[RFC8532] and can avoid mixing the models for the retrieved data from
the retrieval procedures. It is expected that retrieval procedures
will evolve faster than the data model [RFC8532] and will allow new
procedures to be defined for retrieval of the same data defined by
the generic YANG data model for connectionless OAM.
2. Conventions Used in This document
The following terms are defined in [RFC6241] and are used in this
document:
o client
o configuration data
o server
o state data
The following terms are defined in [RFC6020] and are used in this
document:
o augment
o data model
o data node
The terminology for describing YANG data models is found in
[RFC6020].
2.1. Terminology
TP - Test Point
MAC - Media Access Control
RPC - Remote Procedure Call
RPC Operation - A specific Remote Procedure Call
2.2. Tree Diagrams
Tree diagrams used in this document follow the notation defined in
[RFC8340].
3. Overview of the Connectionless OAM Retrieval Methods Model
This document describes an on-demand retrieval method YANG data model
for OAM protocols that use connectionless communication. This model
provides technology-independent retrieval procedures (RPC operations)
for connectionless OAM protocols. It provides a flexible way to
retrieve the data that is defined by the "ietf-connectionless-
oam.yang" module [RFC8532].
3.1. RPC Operation Definitions
The RPC model facilitates issuing commands to a Network Configuration
Protocol (NETCONF) server (in this case to the device that needs to
execute the OAM command) and obtaining a response.
Under the "connectionless-oam-methods" module, we summarize common
OAM functions and define two generic RPC operations: 'continuity-
check' and 'path-discovery'. In practice, these RPC operations are
activated on demand and are supported by corresponding technology-
specific OAM tools [RFC7276]. For example, for the IP OAM model, the
Continuity Check RPC corresponds to the IP Ping [RFC792] [RFC4443],
while the path discovery RPC operation corresponds to IP Traceroute
[RFC792] [RFC4443].
Note that the RPC operation presented in this document is the base
building block, which is used to derive a model for a technology-
specific OAM (i.e., ICMP Ping [RFC792] [RFC4443] and Label Switched
Path (LSP) Ping [RFC8029]). This base building block should be
extended with corresponding technology-specific parameters. To
facilitate this for future enhancements to data retrieval methods,
the RPCs are captured under a separate module.
The generic 'tp-address' grouping is used as data input from
different RPCs described in this document. The generic 'path-
discovery-data' and 'continuity-check-data' groupings defined by the
"ietf-connectionless-oam.yang" module [RFC8532] are used as data
outputs from different RPCs described in this document. Similar
methods, including other RPCs, can retrieve the data using the same
data model (i.e., the "ietf-connectionless-oam.yang" module).
rpc continuity-check {
if-feature cl-oam:continuity-check;
description
"Continuity Check RPC operation as per RFC 7276.";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
input {
uses rpc-input-parameters;
....
}
output {
container response-info {
leaf protocol-id {
type identityref {
base protocol-id;
}
mandatory true;
description
"Protocol used in the Continuity Check. ";
}
leaf protocol-id-meta-data {
type identityref {
base protocol-id-meta-data;
}
description
"An optional metadata related to the protocol ID.";
}
leaf status-code {
type identityref{
base status-code;
}
mandatory true;
description
"Status code for Continuity Check RPC operation.";
}
leaf status-sub-code {
type identityref{
base status-sub-code;
}
mandatory true;
description
"Status-sub-code for Continuity Check RPC operation.";
}
description
"Status code and status-sub-code for Continuity Check RPC
operation.";
}
uses cl-oam:continuity-check-data;
}
}
rpc path-discovery {
description
"Path discovery RPC operation as per RFC 7276.";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
input {
uses rpc-input-parameters;
.....
}
output {
list response-list {
key "response-index";
description
"Path discovery response list.";
leaf response-index {
type uint32;
mandatory true;
description
"Response index.";
}
leaf protocol-id {
type identityref {
base protocol-id;
}
mandatory true;
description
"Protocol used in path discovery. ";
}
leaf protocol-id-meta-data {
type identityref {
base protocol-id-meta-data;
}
description
"An optional metadata related to the protocol ID.";
}
leaf status-code {
type identityref{
base status-code;
}
mandatory true;
description
"Status code for path discovery RPC operation. ";
}
leaf status-sub-code {
type identityref{
base status-sub-code;
}
mandatory true;
description
"Status-sub-code for path discovery RPC operation. ";
}
}
uses cl-oam:path-discovery-data;
}
}
Snippet of Data Hierarchy Related to RPC Operations
3.2. OAM Retrieval Methods Hierarchy
The complete data hierarchy related to the Connectionless OAM
Retrieval Methods YANG data model is presented below.
module: ietf-connectionless-oam-methods
rpcs:
+---x continuity-check {cl-oam:continuity-check}?
| +---w input
| | +---w destination-tp
| | | +---w tp-location-type identityref
| | | +---w mac-address
| | | | +---w mac-address yang:mac-address
| | | +---w ipv4-address
| | | | +---w ipv4-address inet:ipv4-address
| | | +---w ipv6-address
| | | | +---w ipv6-address inet:ipv6-address
| | | +---w tp-attribute
| | | | +---w tp-attribute-type?
| | | | | address-attribute-type
| | | | +---w (tp-attribute-value)?
| | | | +--:(ip-prefix)
| | | | | +---w ip-prefix?
| | | | | inet:ip-prefix
| | | | +--:(bgp)
| | | | | +---w bgp?
| | | | | inet:ip-prefix
| | | | +--:(tunnel)
| | | | | +---w tunnel-interface? uint32
| | | | +--:(pw)
| | | | | +---w remote-pe-address?
| | | | | | inet:ip-address
| | | | | +---w pw-id? uint32
| | | | +--:(vpls)
| | | | | +---w route-distinguisher?
| | | | | | rt:route-distinguisher
| | | | | +---w sender-ve-id? uint16
| | | | | +---w receiver-ve-id? uint16
| | | | +--:(mpls-mldp)
| | | | +---w (root-address)?
| | | | +--:(ip-address)
| | | | | +---w source-address?
| | | | | | inet:ip-address
| | | | | +---w group-ip-address?
| | | | | inet:ip-address
| | | | +--:(vpn)
| | | | | +---w as-number?
| | | | | inet:as-number
| | | | +--:(global-id)
| | | | +---w lsp-id? string
| | | +---w system-info
| | | +---w router-id? rt:router-id
| | +---w source-interface if:interface-ref
| | +---w outbound-interface if:interface-ref
| | +---w vrf?
| | | cl-oam:routing-instance-ref
| | +---w session-type? enumeration
| | +---w count? uint32
| | +---w ttl? uint8
| | +---w packet-size? uint32
| +--ro output
| +--ro response-info
| | +--ro protocol-id identityref
| | +--ro protocol-id-meta-data? identityref
| | +--ro status-code identityref
| | +--ro status-sub-code identityref
| +--ro src-test-point
| | +--ro ni? routing-instance-ref
| | +--ro tp-location-type identityref
| | +--ro mac-address
| | | +--ro mac-address yang:mac-address
| | +--ro ipv4-address
| | | +--ro ipv4-address inet:ipv4-address
| | +--ro ipv6-address
| | | +--ro ipv6-address inet:ipv6-address
| | +--ro tp-attribute
| | | +--ro tp-attribute-type?
| | | | address-attribute-type
| | | +--ro (tp-attribute-value)?
| | | +--:(ip-prefix)
| | | | +--ro ip-prefix?
| | | | inet:ip-prefix
| | | +--:(bgp)
| | | | +--ro bgp?
| | | | inet:ip-prefix
| | | +--:(tunnel)
| | | | +--ro tunnel-interface? uint32
| | | +--:(pw)
| | | | +--ro remote-pe-address?
| | | | | inet:ip-address
| | | | +--ro pw-id? uint32
| | | +--:(vpls)
| | | | +--ro route-distinguisher?
| | | | | rt:route-distinguisher
| | | | +--ro sender-ve-id? uint16
| | | | +--ro receiver-ve-id? uint16
| | | +--:(mpls-mldp)
| | | +--ro (root-address)?
| | | +--:(ip-address)
| | | | +--ro source-address?
| | | | | inet:ip-address
| | | | +--ro group-ip-address?
| | | | inet:ip-address
| | | +--:(vpn)
| | | | +--ro as-number?
| | | | inet:as-number
| | | +--:(global-id)
| | | +--ro lsp-id? string
| | +--ro system-info
| | | +--ro router-id? rt:router-id
| | +--ro egress-intf-name? if:interface-ref
| +--ro dest-test-point
| | +--ro ni? routing-instance-ref
| | +--ro tp-location-type identityref
| | +--ro mac-address
| | | +--ro mac-address yang:mac-address
| | +--ro ipv4-address
| | | +--ro ipv4-address inet:ipv4-address
| | +--ro ipv6-address
| | | +--ro ipv6-address inet:ipv6-address
| | +--ro tp-attribute
| | | +--ro tp-attribute-type?
| | | | address-attribute-type
| | | +--ro (tp-attribute-value)?
| | | +--:(ip-prefix)
| | | | +--ro ip-prefix?
| | | | inet:ip-prefix
| | | +--:(bgp)
| | | | +--ro bgp?
| | | | inet:ip-prefix
| | | +--:(tunnel)
| | | | +--ro tunnel-interface? uint32
| | | +--:(pw)
| | | | +--ro remote-pe-address?
| | | | | inet:ip-address
| | | | +--ro pw-id? uint32
| | | +--:(vpls)
| | | | +--ro route-distinguisher?
| | | | | rt:route-distinguisher
| | | | +--ro sender-ve-id? uint16
| | | | +--ro receiver-ve-id? uint16
| | | +--:(mpls-mldp)
| | | +--ro (root-address)?
| | | +--:(ip-address)
| | | | +--ro source-address?
| | | | | inet:ip-address
| | | | +--ro group-ip-address?
| | | | inet:ip-address
| | | +--:(vpn)
| | | | +--ro as-number?
| | | | inet:as-number
| | | +--:(global-id)
| | | +--ro lsp-id? string
| | +--ro system-info
| | | +--ro router-id? rt:router-id
| | +--ro ingress-intf-name? if:interface-ref
| +--ro sequence-number? uint64
| +--ro hop-cnt? uint8
| +--ro session-packet-statistics
| | +--ro rx-packet-count? uint32
| | +--ro tx-packet-count? uint32
| | +--ro rx-bad-packet? uint32
| | +--ro tx-packet-failed? uint32
| +--ro session-error-statistics
| | +--ro packet-loss-count? uint32
| | +--ro loss-ratio? percentage
| | +--ro packet-reorder-count? uint32
| | +--ro packets-out-of-seq-count? uint32
| | +--ro packets-dup-count? uint32
| +--ro session-delay-statistics
| | +--ro time-unit-value? identityref
| | +--ro min-delay-value? uint32
| | +--ro max-delay-value? uint32
| | +--ro average-delay-value? uint32
| +--ro session-jitter-statistics
| +--ro unit-value? identityref
| +--ro min-jitter-value? uint32
| +--ro max-jitter-value? uint32
| +--ro average-jitter-value? uint32
+---x path-discovery {cl-oam:path-discovery}?
+---w input
| +---w destination-tp
| | +---w tp-location-type identityref
| | +---w mac-address
| | | +---w mac-address yang:mac-address
| | +---w ipv4-address
| | | +---w ipv4-address inet:ipv4-address
| | +---w ipv6-address
| | | +---w ipv6-address inet:ipv6-address
| | +---w tp-attribute
| | | +---w tp-attribute-type?
| | | | address-attribute-type
| | | +---w (tp-attribute-value)?
| | | +--:(ip-prefix)
| | | | +---w ip-prefix?
| | | | inet:ip-prefix
| | | +--:(bgp)
| | | | +---w bgp?
| | | | inet:ip-prefix
| | | +--:(tunnel)
| | | | +---w tunnel-interface? uint32
| | | +--:(pw)
| | | | +---w remote-pe-address?
| | | | | inet:ip-address
| | | | +---w pw-id? uint32
| | | +--:(vpls)
| | | | +---w route-distinguisher?
| | | | | rt:route-distinguisher
| | | | +---w sender-ve-id? uint16
| | | | +---w receiver-ve-id? uint16
| | | +--:(mpls-mldp)
| | | +---w (root-address)?
| | | +--:(ip-address)
| | | | +---w source-address?
| | | | | inet:ip-address
| | | | +---w group-ip-address?
| | | | inet:ip-address
| | | +--:(vpn)
| | | | +---w as-number?
| | | | inet:as-number
| | | +--:(global-id)
| | | +---w lsp-id? string
| | +---w system-info
| | +---w router-id? rt:router-id
| +---w source-interface if:interface-ref
| +---w outbound-interface if:interface-ref
| +---w vrf?
| | cl-oam:routing-instance-ref
| +---w session-type? enumeration
| +---w max-ttl? uint8
+--ro output
+--ro response-list* [response-index]
| +--ro response-index uint32
| +--ro protocol-id identityref
| +--ro protocol-id-meta-data? identityref
| +--ro status-code identityref
| +--ro status-sub-code identityref
+--ro src-test-point
| +--ro ni? routing-instance-ref
| +--ro tp-location-type identityref
| +--ro mac-address
| | +--ro mac-address yang:mac-address
| +--ro ipv4-address
| | +--ro ipv4-address inet:ipv4-address
| +--ro ipv6-address
| | +--ro ipv6-address inet:ipv6-address
| +--ro tp-attribute
| | +--ro tp-attribute-type?
| | | address-attribute-type
| | +--ro (tp-attribute-value)?
| | +--:(ip-prefix)
| | | +--ro ip-prefix?
| | | inet:ip-prefix
| | +--:(bgp)
| | | +--ro bgp?
| | | inet:ip-prefix
| | +--:(tunnel)
| | | +--ro tunnel-interface? uint32
| | +--:(pw)
| | | +--ro remote-pe-address?
| | | | inet:ip-address
| | | +--ro pw-id? uint32
| | +--:(vpls)
| | | +--ro route-distinguisher?
| | | | rt:route-distinguisher
| | | +--ro sender-ve-id? uint16
| | | +--ro receiver-ve-id? uint16
| | +--:(mpls-mldp)
| | +--ro (root-address)?
| | +--:(ip-address)
| | | +--ro source-address?
| | | | inet:ip-address
| | | +--ro group-ip-address?
| | | inet:ip-address
| | +--:(vpn)
| | | +--ro as-number?
| | | inet:as-number
| | +--:(global-id)
| | +--ro lsp-id? string
| +--ro system-info
| +--ro router-id? rt:router-id
+--ro dest-test-point
| +--ro ni? routing-instance-ref
| +--ro tp-location-type identityref
| +--ro mac-address
| | +--ro mac-address yang:mac-address
| +--ro ipv4-address
| | +--ro ipv4-address inet:ipv4-address
| +--ro ipv6-address
| | +--ro ipv6-address inet:ipv6-address
| +--ro tp-attribute
| | +--ro tp-attribute-type?
| | | address-attribute-type
| | +--ro (tp-attribute-value)?
| | +--:(ip-prefix)
| | | +--ro ip-prefix?
| | | inet:ip-prefix
| | +--:(bgp)
| | | +--ro bgp?
| | | inet:ip-prefix
| | +--:(tunnel)
| | | +--ro tunnel-interface? uint32
| | +--:(pw)
| | | +--ro remote-pe-address?
| | | | inet:ip-address
| | | +--ro pw-id? uint32
| | +--:(vpls)
| | | +--ro route-distinguisher?
| | | | rt:route-distinguisher
| | | +--ro sender-ve-id? uint16
| | | +--ro receiver-ve-id? uint16
| | +--:(mpls-mldp)
| | +--ro (root-address)?
| | +--:(ip-address)
| | | +--ro source-address?
| | | | inet:ip-address
| | | +--ro group-ip-address?
| | | inet:ip-address
| | +--:(vpn)
| | | +--ro as-number?
| | | inet:as-number
| | +--:(global-id)
| | +--ro lsp-id? string
| +--ro system-info
| +--ro router-id? rt:router-id
+--ro sequence-number? uint64
+--ro hop-cnt? uint8
+--ro session-packet-statistics
| +--ro rx-packet-count? uint32
| +--ro tx-packet-count? uint32
| +--ro rx-bad-packet? uint32
| +--ro tx-packet-failed? uint32
+--ro session-error-statistics
| +--ro packet-loss-count? uint32
| +--ro loss-ratio? percentage
| +--ro packet-reorder-count? uint32
| +--ro packets-out-of-seq-count? uint32
| +--ro packets-dup-count? uint32
+--ro session-delay-statistics
| +--ro time-unit-value? identityref
| +--ro min-delay-value? uint32
| +--ro max-delay-value? uint32
| +--ro average-delay-value? uint32
+--ro session-jitter-statistics
| +--ro unit-value? identityref
| +--ro min-jitter-value? uint32
| +--ro max-jitter-value? uint32
| +--ro average-jitter-value? uint32
+--ro path-verification
| +--ro flow-info?
| | string
| +--ro session-path-verification-statistics
| +--ro verified-count? uint32
| +--ro failed-count? uint32
+--ro path-trace-info
+--ro path-trace-info-list* [index]
+--ro index uint32
+--ro ni?
| routing-instance-ref
+--ro tp-location-type identityref
+--ro mac-address
| +--ro mac-address yang:mac-address
+--ro ipv4-address
| +--ro ipv4-address inet:ipv4-address
+--ro ipv6-address
| +--ro ipv6-address inet:ipv6-address
+--ro tp-attribute
| +--ro tp-attribute-type?
| | address-attribute-type
| +--ro (tp-attribute-value)?
| +--:(ip-prefix)
| | +--ro ip-prefix?
| | inet:ip-prefix
| +--:(bgp)
| | +--ro bgp?
| | inet:ip-prefix
| +--:(tunnel)
| | +--ro tunnel-interface?
| | uint32
| +--:(pw)
| | +--ro remote-pe-address?
| | | inet:ip-address
| | +--ro pw-id?
| | uint32
| +--:(vpls)
| | +--ro route-distinguisher?
| | | rt:route-distinguisher
| | +--ro sender-ve-id?
| | | uint16
| | +--ro receiver-ve-id?
| | uint16
| +--:(mpls-mldp)
| +--ro (root-address)?
| +--:(ip-address)
| | +--ro source-address?
| | | inet:ip-address
| | +--ro group-ip-address?
| | inet:ip-address
| +--:(vpn)
| | +--ro as-number?
| | inet:as-number
| +--:(global-id)
| +--ro lsp-id?
| string
+--ro system-info
| +--ro router-id? rt:router-id
+--ro timestamp-type? identityref
+--ro timestamp-64bit
| +--ro timestamp-sec? uint32
| +--ro timestamp-nanosec? uint32
+--ro timestamp-80bit {ptp-long-format}?
| +--ro timestamp-sec? uint64
| +--ro timestamp-nanosec? uint32
+--ro ntp-timestamp-32bit
| {ntp-short-format}?
| +--ro timestamp-sec? uint16
| +--ro timestamp-nanosec? uint16
+--ro icmp-timestamp-32bit {icmp-timestamp}?
| +--ro timestamp-millisec? uint32
+--ro ingress-intf-name?
| if:interface-ref
+--ro egress-intf-name?
| if:interface-ref
+--ro queue-depth? uint32
+--ro transit-delay? uint32
+--ro app-meta-data? uint64
Data Hierarchy of OAM Retrieval Methods
4. OAM Retrieval Methods YANG Module
<CODE BEGINS> file
"ietf-connectionless-oam-methods@2019-04-16.yang"
module ietf-connectionless-oam-methods {
namespace
"urn:ietf:params:xml:ns:yang:ietf-connectionless-oam-methods";
prefix cloam-methods;
import ietf-interfaces {
prefix if;
}
import ietf-connectionless-oam {
prefix cl-oam;
}
organization
"IETF LIME Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/lime>
WG List: <mailto:lmap@ietf.org>
Deepak Kumar <dekumar@cisco.com>
Qin Wu <bill.wu@huawei.com>
Srihari Raghavan <rihari@cisco.com>
Michael Wang <wangzitao@huawei.com>
Reshad Rahman <rrahman@cisco.com>";
description
"This YANG module defines the RPC operations for
connectionless OAM to be used within the IETF
in a protocol-independent manner. It is
assumed that each protocol maps corresponding
abstracts to its native format. Each protocol
may extend the YANG data model defined here to
include protocol-specific extensions.
Copyright (c) 2019 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 8533; see
the RFC itself for full legal notices.";
revision 2019-04-16 {
description
"Initial revision.";
reference
"RFC 8533: Retrieval Methods YANG Data Model for the Management
of Operations, Administration, and Maintenance (OAM)
Protocols That Use Connectionless Communications";
}
identity protocol-id {
description
"This is the base identity for a generic protocol
ID. The protocol registry can be found at
https://www.iana.org/protocols.";
}
identity protocol-id-internet {
base protocol-id;
description
"Identity for Internet Protocols.";
}
identity protocol-id-proprietary {
base protocol-id;
description
"Identity for proprietary protocols (e.g.,
IP SLA).";
}
identity protocol-id-sfc {
base protocol-id;
description
"Identity for Service Function Chaining.";
}
identity protocol-id-mpls {
base protocol-id;
description
"The MPLS protocol.";
}
identity protocol-id-mpls-tp {
base protocol-id;
description
"The MPLS-TP protocol.";
}
identity protocol-id-twamp {
base protocol-id;
description
"The Two-Way Active Measurement Protocol (TWAMP)
protocol.";
}
identity protocol-id-bier {
base protocol-id;
description
"The Bit Index Explicit Replication (BIER)
protocol.";
}
identity status-code {
description
"This is base identity for a status code.";
}
identity success-reach {
base status-code;
description
"Indicates that the destination being verified
is reachable (see RFC 7276).";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
}
identity fail-reach {
base status-code;
description
"Indicates that the destination being verified
is not reachable (see RFC 7276).";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
}
identity success-path-verification {
base status-code;
description
"Indicates that the path verification is performed
successfully (see RFC 7276).";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
}
identity fail-path-verification {
base status-code;
description
"Indicates that the path verification fails
(see RFC 7276).";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
}
identity status-sub-code {
description
"IdentityBase status-sub-code.";
}
identity invalid-cc {
base status-sub-code;
description
"Indicates that the Continuity Check message is invalid
(see RFC 7276).";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
}
identity invalid-pd {
base status-sub-code;
description
"Indicates that the path discovery message is invalid
(see RFC 7276).";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
}
identity protocol-id-meta-data {
description
"This is the base identity for metadata that corresponds
to the protocol ID.";
}
identity protocol-internet-number {
base protocol-id-meta-data;
description
"Internet Protocol number for standard
Internet Protocols (IANA-assigned Internet
Protocol numbers) to help in protocol processing.
The Protocol Numbers registry can be found at
https://www.iana.org/assignments/protocol-numbers.";
}
grouping rpc-input-parameters {
container destination-tp {
uses cl-oam:tp-address;
description
"Destination test point.";
}
leaf source-interface {
type if:interface-ref;
mandatory true;
description
"Source interface.";
}
leaf outbound-interface {
type if:interface-ref;
mandatory true;
description
"Outbound interface.";
}
leaf vrf {
type cl-oam:routing-instance-ref;
description
"Virtual Routing and Forwarding (VRF) instance.";
}
description
"Grouping for RPC input parameters";
}
rpc continuity-check {
if-feature "cl-oam:continuity-check";
description
"Continuity Check RPC operation as per RFC 7276.";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
input {
uses rpc-input-parameters;
uses cl-oam:session-type {
description
"If session-type is specified, then session-type
must be set to on demand";
}
leaf count {
type uint32 {
range "0..4294967295" {
description
"The overall number of packets to be transmitted
by the sender. The value of the count will be set
to zero (0) on creation and will thereafter
increase monotonically until it reaches a maximum
value of 2^32-1 (4294967295 decimal), when it wraps
around and starts increasing again from zero.";
}
}
default "5";
description
"Specifies the number of
packets that will be sent. By
default, the packet number is
set to 5.";
}
leaf ttl {
type uint8;
default "255";
description
"Time to live (TTL) used to limit the lifetime
of data packets transmitted in the network
to prevent looping. The TTL value is decremented
for every hop that the packet traverses. If the
TTL is zero, the data packet will be discarded.";
}
leaf packet-size {
type uint32 {
range "64..10000";
}
default "64";
description
"Packet size of the Continuity Check message, in octets.
By default, the packet size is set to 64 octets.";
}
}
output {
container response-info {
leaf protocol-id {
type identityref {
base protocol-id;
}
mandatory true;
description
"Protocol used in the Continuity Check message.
This could be a standard protocol (e.g.,
TCP/IP protocols, MPLS, etc.) or a proprietary
protocol as identified by this field.";
}
leaf protocol-id-meta-data {
type identityref {
base protocol-id-meta-data;
}
description
"An optional metadata related to the protocol ID.
For example, this could be the Internet Protocol
number for standard Internet Protocols used for
help with protocol processing.";
}
leaf status-code {
type identityref {
base status-code;
}
mandatory true;
description
"Status code for Continuity Check RPC operation.
This could be a basic status code (e.g., destination
is reachable or destination is not reachable; see RFC 7276)
or some customized status code as identified by this
field.";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
}
leaf status-sub-code {
type identityref {
base status-sub-code;
}
mandatory true;
description
"An optional status-sub-code for Continuity Check
RPC operation. If the basic status code is destination
reachable, this status-sub-code doesn't need to be
specified. If the basic status code is destination
unreachable, the status-sub-code can be used to specify
the detailed reasons. This could be a basic
sub-status-code (such as an invalid Continuity Check) or
other error codes specific to the protocol under use for
the Continuity Checks. For example, if ICMP is the
protocol under use, the error codes defined in RFC 4443
can be used to specify the reasons specific to ICMP.
This technology-specific status-sub-code can be
defined in technology-specific models.";
reference
"RFC 4443: The IETF Administrative Oversight Committee
(IAOC) Member Selection Guidelines and Process.";
}
description
"Status code and status-sub-code for Continuity Check RPC
operation.";
}
uses cl-oam:continuity-check-data;
}
}
rpc path-discovery {
if-feature "cl-oam:path-discovery";
description
"Path discovery RPC operation as per RFC 7276.";
reference
"RFC 7276: An Overview of Operations, Administration, and
Maintenance (OAM) Tools";
input {
uses rpc-input-parameters;
uses cl-oam:session-type {
description
"If session-type is specified, then session-type
must be set to on demand";
}
leaf max-ttl {
type uint8;
default "255";
description
"Maximum TTL indicates the maximum number of hops that
a packet is permitted to travel before being discarded
by a router. By default, the maximum TTL is set to
255.";
}
}
output {
list response-list {
key "response-index";
description
"Path discovery response list.";
leaf response-index {
type uint32;
mandatory true;
description
"Response index.";
}
leaf protocol-id {
type identityref {
base protocol-id;
}
mandatory true;
description
"Protocol used in path discovery. This could be a
standard protocol (e.g., TCP/IP protocols, MPLS, etc.)
or a proprietary protocol as identified by
this field.";
}
leaf protocol-id-meta-data {
type identityref {
base protocol-id-meta-data;
}
description
"An optional metadata related to the protocol ID.
For example, this could be the Internet Protocol
number for standard Internet Protocols used for
help with protocol processing.";
}
leaf status-code {
type identityref {
base status-code;
}
mandatory true;
description
"Status code for Continuity Check RPC operation.
This could be a basic status code (e.g., destination
is reachable or destination is not reachable) or some
customized status code as identified by this field.";
}
leaf status-sub-code {
type identityref {
base status-sub-code;
}
mandatory true;
description
"An optional status-sub-code for Continuity Check
RPC operation. If the basic status code is destination
reachable, this status-sub-code doesn't need to be
specified. If the basic status code is destination
unreachable, the status-sub-code can be used to specify
the detailed reasons. This could be a basic
sub-status-code (such as an invalid Continuity Check) or
other error codes specific to the protocol under use for
Continuity Checks. For example, if ICMP is the protocol
under use, the error codes defined in RFC 4443
can be used to specify the reasons specific to ICMP.
This technology-specific status-sub-code can be defined
in technology-specific models.";
reference
"RFC 4443: The IETF Administrative Oversight Committee
(IAOC) Member Selection Guidelines and Process.";
}
}
uses cl-oam:path-discovery-data;
}
}
}
<CODE ENDS>
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.
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:
o continuity-check: Generates Continuity Check.
o path-discovery: Generates path discovery.
These operations are used to retrieve the data from the device that
needs to execute the OAM command. Unauthorized source access to some
sensitive information in the above data may be used for network
reconnaissance or lead to denial-of-service attacks on both the local
device and the network.
6. IANA Considerations
This document registers a URI in the "IETF XML Registry" [RFC3688].
The following registration has been made:
URI: urn:ietf:params:xml:ns:yang:ietf-connectionless-oam-methods
Registrant Contact: The IESG. XML: N/A, the requested URI is an XML
namespace.
This document registers a YANG module in the "YANG Module Names"
registry [RFC6020].
name: ietf-connectionless-oam-methods
namespace:
urn:ietf:params:xml:ns:yang:ietf-connectionless-oam-methods
prefix: cloam-methods
reference: RFC 8533
7. References
7.1. Normative References
[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>.
[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>.
[RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken,
"Specification of the IP Flow Information Export (IPFIX)
Protocol for the Exchange of Flow Information", STD 77,
RFC 7011, DOI 10.17487/RFC7011, September 2013,
<https://www.rfc-editor.org/info/rfc7011>.
[RFC792] Postel, J., "Internet Control Message Protocol", STD 5,
RFC 792, DOI 10.17487/RFC0792, September 1981.
[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>.
[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>.
[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>.
[RFC8532] Kumar, D., Wang, M., Wu, Q., Ed., Rahman, R., and
S. Raghavan, "Generic YANG Data Model for the Management of
Operations, Administration, and Maintenance (OAM)
Protocols That Use Connectionless Communications",
RFC 8532, DOI 10.17487/RFC8532, April 2019,
<https://www.rfc-editor.org/info/rfc8532>.
7.2. Informative References
[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet
Control Message Protocol (ICMPv6) for the Internet
Protocol Version 6 (IPv6) Specification", STD 89,
RFC 4443, DOI 10.17487/RFC4443, March 2006,
<https://www.rfc-editor.org/info/rfc4443>.
[RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
(BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010,
<https://www.rfc-editor.org/info/rfc5880>.
[RFC7276] Mizrahi, T., Sprecher, N., Bellagamba, E., and Y.
Weingarten, "An Overview of Operations, Administration,
and Maintenance (OAM) Tools", RFC 7276,
DOI 10.17487/RFC7276, June 2014,
<https://www.rfc-editor.org/info/rfc7276>.
[RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
Aldrin, S., and M. Chen, "Detecting Multiprotocol Label
Switched (MPLS) Data-Plane Failures", RFC 8029,
DOI 10.17487/RFC8029, March 2017,
<https://www.rfc-editor.org/info/rfc8029>.
[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>.
[RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of
Documents Containing YANG Data Models", BCP 216, RFC 8407,
DOI 10.17487/RFC8407, October 2018,
<https://www.rfc-editor.org/info/rfc8407>.
[YANG-Push]
Clemm, A., Voit, E., Prieto, A., Tripathy, A., Nilsen-
Nygaard, E., Bierman, A., and B. Lengyel, "Subscription to
YANG Datastores", Work in Progress, draft-ietf-netconf-
yang-push-22, February 2019.
Appendix A. Extending Connectionless OAM Method Module Example
The following is an example of extensions possible to the
"ietf-connectionless-oam-methods" YANG data model defined in this document.
The snippet below depicts an example of augmenting the
"ietf-connectionless-oam-methods" YANG data model with ICMP ping
attributes:
augment "/cloam-methods:continuity-check"
+"/cloam-methods:output"{
container session-rtt-statistics{
leaf min-rtt{
type uint32;
description
"This minimum ping round-trip-time (RTT) received.";
}
leaf max-rtt{
type uint32;
description
"This maximum ping RTT received.";
}
leaf avg-rtt{
type uint32;
description
"The current average ping RTT.";
}
description
"This container presents the ping RTT statistics.";
}
}
A.1. Example of New Retrieval Procedures Model
As discussed in the Introduction section of this document, the new
retrieval procedures can be defined for retrieval of the same data
defined by the base YANG data model for connectionless OAM protocols.
This appendix demonstrates how the base connectionless OAM data model
can be extended to support persistent data retrieval besides
on-demand retrieval procedures defined in Section 3, i.e., first
retrieve a persistent-id based on the destination test point location
information, and then retrieve the export details based on
persistent-id. Internet Protocol Flow Information Export (IPFIX)
[RFC7011] or YANG-Push [YANG-Push] are currently outlined here as
data export options. Additional export options can be added in the
future.
The YANG module "example-cl-oam-persistent-methods" shown below is
intended as an illustration rather than a real definition of an RPC
operation model for persistent data retrieval. For the sake of
brevity, this module does not obey all the guidelines specified in
[RFC8407].
module example-cl-oam-persistent-methods {
namespace "http://example.com/cl-oam-persistent-methods";
prefix pcloam-methods;
import ietf-interfaces {
prefix if;
}
import ietf-connectionless-oam {
prefix cl-oam;
}
import ietf-yang-types {
prefix yang;
}
identity export-method {
description
"Base identity to represent a conceptual
export-method.";
}
identity ipfix-export {
base export-method;
description
"IPFIX-based export. Configuration provided
separately.";
}
identity yang-push-export {
base export-method;
description
"YANG-Push from draft-ietf-netconf-yang-push.";
}
identity protocol-id {
description
"A generic protocol identifier.";
}
identity status-code {
description
"Base status code.";
}
identity success-reach {
base status-code;
description
"Indicates that the destination being verified
is reachable.";
}
identity fail-reach {
base status-code;
description
"Indicates that the destination being verified
is not reachable";
}
identity success-path-verification {
base status-code;
description
"Indicates that the path verification is performed
successfully.";
}
identity fail-path-verification {
base status-code;
description
"Indicates that the path verification fails.";
}
identity status-sub-code {
description
"Base status-sub-code.";
}
identity invalid-cc {
base status-sub-code;
description
"Indicates that the Continuity Check message is
invalid.";
}
identity invalid-pd {
base status-sub-code;
description
"Indicates that the path discovery message is invalid.";
}
typedef export-method {
type identityref {
base export-method;
}
description
"Export method type.";
}
typedef change-type {
type enumeration {
enum create {
description
"Change due to a create.";
}
enum delete {
description
"Change due to a delete.";
}
enum modify {
description
"Change due to an update.";
}
}
description
"Different types of changes that may occur.";
}
rpc cc-get-persistent-id {
if-feature "cl-oam:continuity-check";
description
"Obtains Continuity Check persistent identification
given mapping parameters as input.";
input {
container destination-tp {
uses cl-oam:tp-address;
description
"Destination test point.";
}
uses cl-oam:session-type;
leaf source-interface {
type if:interface-ref;
description
"Source interface.";
}
leaf outbound-interface {
type if:interface-ref;
description
"Outbound interface.";
}
leaf vrf {
type cl-oam:routing-instance-ref;
description
"VRF instance.";
}
}
output {
container error-code {
leaf protocol-id {
type identityref {
base protocol-id;
}
mandatory true;
description
"Protocol used. This could be a standard
protocol (e.g., TCP/IP protocols, MPLS, etc.)
or a proprietary protocol as identified by
this field.";
}
leaf protocol-id-meta-data {
type uint64;
description
"An optional metadata related to the protocol ID.
For example, this could be the Internet Protocol
number for standard Internet Protocols used for
help with protocol processing.";
}
leaf status-code {
type identityref {
base status-code;
}
mandatory true;
description
"Status code.";
}
leaf status-sub-code {
type identityref {
base status-sub-code;
}
mandatory true;
description
"Sub code for the Continuity Check.";
}
description
"Status code and sub code.";
}
leaf cc-persistent-id {
type string;
description
"Id to act as a cookie.";
}
}
}
rpc cc-persistent-get-export-details {
if-feature "cl-oam:continuity-check";
description
"Given the persistent ID, gets the configuration
options and details related to the configured data
export.";
input {
leaf cc-persistent-id {
type string;
description
"Persistent ID for use as a key in search.";
}
}
output {
container error-code {
leaf protocol-id {
type identityref {
base protocol-id;
}
mandatory true;
description
"Protocol used. This could be a standard
protocol (e.g., TCP/IP protocols, MPLS, etc.)
or a proprietary protocol as identified by
this field.";
}
leaf protocol-id-meta-data {
type uint64;
description
"An optional metadata related to the protocol ID.
For example, this could be the Internet Protocol
number for standard Internet Protocols used for
help with protocol processing.";
}
leaf status-code {
type identityref {
base status-code;
}
mandatory true;
description
"Status code.";
}
leaf status-sub-code {
type identityref {
base status-sub-code;
}
mandatory true;
description
"Sub code for the Continuity Check.";
}
description
"Status code and sub code.";
}
leaf data-export-method {
type export-method;
description
"Type of export in use.";
}
choice cc-trigger {
description
"Necessary conditions for
periodic or on-change trigger.";
case periodic {
description
"Periodic reports.";
leaf period {
type yang:timeticks;
description
"Time interval between reports.";
}
leaf start-time {
type yang:date-and-time;
description
"Timestamp from which reports were started.";
}
}
case on-change {
description
"On-change trigger and not periodic.";
leaf all-data-on-start {
type boolean;
description
"Full update done on start or not.";
}
leaf-list excluded-change {
type change-type;
description
"Changes that will not trigger an update.";
}
}
}
}
}
rpc pd-get-persistent-id {
if-feature "cl-oam:path-discovery";
description
"Obtains persistent path discovery identification.";
input {
container destination-tp {
uses cl-oam:tp-address;
description
"Destination test point.";
}
uses cl-oam:session-type;
leaf source-interface {
type if:interface-ref;
description
"Source interface.";
}
leaf outbound-interface {
type if:interface-ref;
description
"Outbound interface.";
}
leaf vrf {
type cl-oam:routing-instance-ref;
description
"VRF";
}
}
output {
list response-list {
key "response-index";
description
"Path discovery response list.";
leaf response-index {
type uint32;
mandatory true;
description
"Response index.";
}
leaf protocol-id {
type identityref {
base protocol-id;
}
mandatory true;
description
"Protocol used. This could be a standard
protocol (e.g., TCP/IP protocols, MPLS, etc.)
or a proprietary protocol as identified by
this field.";
}
leaf protocol-id-meta-data {
type uint64;
description
"An optional metadata related to the protocol ID.
For example, this could be the Internet Protocol
number for standard Internet Protocols used for
help with protocol processing.";
}
leaf status-code {
type identityref {
base status-code;
}
mandatory true;
description
"Status code for persistent path discovery
information.";
}
leaf status-sub-code {
type identityref {
base status-sub-code;
}
mandatory true;
description
"Sub code for persistent path discovery
information.";
}
leaf pd-persistent-id {
type string;
description
"Id to act as a cookie.";
}
}
}
}
rpc pd-persistent-get-export-details {
if-feature "cl-oam:path-discovery";
description
"Given the persistent ID, gets the configuration
options and details related to the configured data
export.";
input {
leaf cc-persistent-id {
type string;
description
"Persistent ID for use as a key in search.";
}
}
output {
list response-list {
key "response-index";
description
"Path discovery response list.";
leaf response-index {
type uint32;
mandatory true;
description
"Response index.";
}
leaf protocol-id {
type identityref {
base protocol-id;
}
mandatory true;
description
"Protocol used. This could be a standard
protocol (e.g., TCP/IP protocols, MPLS, etc.)
or a proprietary protocol as identified by
this field.";
}
leaf protocol-id-meta-data {
type uint64;
description
"An optional metadata related to the protocol ID.
For example, this could be the Internet Protocol
number for standard Internet Protocols used for
help with protocol processing.";
}
leaf status-code {
type identityref {
base status-code;
}
mandatory true;
description
"Status code for persistent path discovery
creation.";
}
leaf status-sub-code {
type identityref {
base status-sub-code;
}
mandatory true;
description
"Sub code for persistent path discovery
creation.";
}
leaf data-export-method {
type export-method;
description
"Type of export.";
}
choice pd-trigger {
description
"Necessary conditions
for periodic or on-change
trigger.";
case periodic {
description
"Periodic reports.";
leaf period {
type yang:timeticks;
description
"Time interval between reports.";
}
leaf start-time {
type yang:date-and-time;
description
"Timestamp from which reports are started.";
}
}
case on-change {
description
"On-change trigger and not periodic.";
leaf all-data-on-start {
type boolean;
description
"Full update done on start or not.";
}
leaf-list excluded-change {
type change-type;
description
"Changes that will not trigger an update.";
}
}
}
}
}
}
}
Acknowledgements
The authors of this document would like to thank Elwyn Davies, Alia
Atlas, Brian E. Carpenter, Greg Mirsky, Adam Roach, Alissa Cooper,
Eric Rescorla, Ben Campbell, Benoit Claise, Kathleen Moriarty, Carlos
Pignataro, Benjamin Kaduk, and others for their substantive review,
comments, and proposals to improve the document.
Authors' Addresses
Deepak Kumar
CISCO Systems
510 McCarthy Blvd.
Milpitas, CA 95035
United States of America
Email: dekumar@cisco.com
Michael Wang
Huawei Technologies, Co., Ltd
101 Software Avenue, Yuhua District
Nanjing 210012
China
Email: wangzitao@huawei.com
Qin Wu (editor)
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
Reshad Rahman
CISCO Systems
2000 Innovation Drive
Kanata, Ontario K2K 3E8
Canada
Email: rrahman@cisco.com
Srihari Raghavan
CISCO Systems
Tril Infopark Sez, Ramanujan IT City
Neville Block, 2nd floor, Old Mahabalipuram Road
Chennai, Tamil Nadu 600113
India
Email: srihari@cisco.com
AI ELI5
On this page
PROBLEMConnectionless networks have many similar OAM tools such as ping and traceroute, and each is driven differently, while retrieval procedures are expected to change faster than the data they retrieve.
MECHANISMThe RFC defines a separate YANG module with two technology-independent on-demand RPC operations, continuity-check and path-discovery, which return data defined by the generic connectionless OAM model in RFC 8532.
WHY IT MATTERSTechnology-specific OAM models can extend these RPCs, and new retrieval methods can be added later without touching the data model.
§1Why a Separate Retrieval Model
OAM (Operations, Administration, and Maintenance) lets operators monitor communications, troubleshoot failures and monitor service levels and performance. Ping and Traceroute (RFC 4443) and Bidirectional Forwarding Detection (RFC 5880) are well-known fault verification and isolation tools for IP networks, and other technologies built similar toolsets.
RFC 8533 defines an on-demand retrieval method YANG model for OAM protocols that use connectionless communication. It is split out from the generic connectionless OAM model in RFC 8532 so that the retrieved data and the retrieval procedures are not mixed. The RFC expects retrieval procedures to evolve faster than the data model, and new procedures can then be defined for the same data.
The list of facts about the network lives in one place, and the way you ask for those facts lives in another. That way the questions can change without rewriting the facts.
§3Two Generic RPC Operations
The model works through remote procedure calls sent to a NETCONF server, meaning the device that needs to execute the OAM command, and returns a response. The module ietf-connectionless-oam-methods summarizes common OAM functions as two generic RPCs: continuity-check and path-discovery. They are run on demand and map onto technology-specific tools from RFC 7276. For the IP OAM model, continuity check corresponds to IP Ping and path discovery to IP Traceroute.
These RPCs are a base building block. They are meant to be extended with technology-specific parameters to derive models for, for example, ICMP Ping or Label Switched Path (LSP) Ping (RFC 8029). That is why the RPCs sit in their own module.
Each RPC is available only if the matching feature from the RFC 8532 module is supported.
There are two basic questions a tool can ask: 'can I reach it?' and 'what route do I take to get there?'. These are the same ideas as ping and traceroute.
continuity-checkclient → deviceVerifies reachability; corresponds to IP Ping.
ALONGSIDE
path-discoveryclient → deviceFinds the path; corresponds to IP Traceroute.
§3.1Inputs and Outputs
Both RPCs share a grouping of input parameters: a destination test point (whose address grouping comes from the RFC 8532 module), a mandatory source interface and outbound interface, and an optional VRF (Virtual Routing and Forwarding instance). The continuity check also takes a session type, which must be on demand if given, a packet count (default 5), a ttl (default 255) and a packet-size in octets (range 64 to 10000, default 64).
The outputs reuse data groupings from the RFC 8532 module (continuity-check-data and path-discovery-data). Each response also carries a protocol ID, optional protocol metadata (for example the Internet Protocol number), a status code and a status sub-code. Path discovery returns a list of responses with a response-index.
You tell the tool where to start, where to aim and how many test messages to send. It answers with who replied and whether the test passed.
§4Status Codes and Identities
The module defines identities so that results are comparable across technologies. The base status codes, taken from the reachability and path verification ideas in RFC 7276, are success-reach, fail-reach, success-path-verification and fail-path-verification. Two sub-codes give more detail: invalid-cc and invalid-pd, for an invalid Continuity Check message or path discovery message.
Protocol IDs identify what ran the test. The module defines identities for Internet protocols, proprietary protocols, Service Function Chaining, MPLS, MPLS-TP, TWAMP and BIER. If a technology needs its own codes, such as ICMP error codes from RFC 4443 for a ping, it can define them in its own model.
Each answer comes with a result label like 'reached' or 'not reached', plus an optional reason. The labels are the same for every kind of network.
§6Extending the Methods
Appendix A shows two kinds of extension. The first augments the continuity-check output with ping round-trip statistics: a container with minimum, maximum and average RTT values.
The second sketches new retrieval procedures for the same data. It shows persistent retrieval: first retrieve a persistent ID based on the destination test point, then retrieve the export details. Data could be exported with IPFIX (RFC 7011) or YANG-Push. The module there is an illustration rather than a real definition, and it does not follow every guideline in RFC 8407.
You can add extra boxes to the answer form, such as how long a reply took. You can also invent new ways to ask, and the facts stay the same.
§5Security and IANA
The module is accessed through NETCONF (RFC 6241) or RESTCONF (RFC 8040), with SSH and TLS as the mandatory-to-implement secure transports, and access can be limited with NACM (RFC 8341).
The two RPC operations, continuity-check and path-discovery, may be sensitive in some environments, so access to them should be controlled. Unauthorized access to the data they retrieve may be used for network reconnaissance or lead to denial-of-service attacks on both the local device and the network.
IANA registered the namespace urn:ietf:params:xml:ns:yang:ietf-connectionless-oam-methods and the YANG module ietf-connectionless-oam-methods with prefix cloam-methods.
Asking the network to run tests should only be allowed for trusted people. Otherwise someone could use the answers to spy on the network or bury it in test traffic.
§7References
[RFC7276]RFC 7276"An Overview of Operations, Administration, and Maintenance (OAM) Tools", RFC 7276.June 2014[RFC8532]RFC 8532"Generic YANG Data Model for the Management of Operations, Administration, and Maintenance (OAM) Protocols That Use Connectionless Communications", RFC 8532.April 2019[RFC6241]RFC 6241Enns, R., Ed., et al., "Network Configuration Protocol (NETCONF)", RFC 6241, June 2011.June 2011[RFC8040]RFC 8040Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, January 2017.January 2017[RFC8029]RFC 8029"Detecting Multiprotocol Label Switched (MPLS) Data-Plane Failures", RFC 8029.March 2017