BFD Stability
draft-ietf-bfd-stability-11
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Active".
|
|
|---|---|---|---|
| Authors | Ashesh Mishra , Mahesh Jethanandani , Ankur Saxena , Santosh Pallagatti , Mach Chen , Peng Fan | ||
| Last updated | 2024-01-22 (Latest revision 2021-04-12) | ||
| Replaces | draft-ashesh-bfd-stability | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews |
YANGDOCTORS Last Call review
(of
-08)
by Ebben Aries
Ready w/nits
|
||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | Held by WG | |
| Document shepherd | Reshad Rahman | ||
| Shepherd write-up | Show Last changed 2020-07-23 | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | Reshad Rahman <rrahman@cisco.com> |
draft-ietf-bfd-stability-11
Network Working Group A. Mishra
Internet-Draft SES
Intended status: Standards Track M. Jethanandani
Expires: 25 July 2024 Kloud Services
A. Saxena
Ciena Corporation
S. Pallagatti
VMware
M. Chen
Huawei
P. Fan
China Mobile
22 January 2024
BFD Stability
draft-ietf-bfd-stability-11
Abstract
This document describes extensions to the Bidirectional Forwarding
Detection (BFD) protocol to measure BFD stability. Specifically, it
describes a mechanism for detection of BFD packet loss.
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 July 2024.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. BFD Null-Authentication Type . . . . . . . . . . . . . . . . 3
5. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 3
5.1. Loss Measurement . . . . . . . . . . . . . . . . . . . . 4
6. ietf-bfd-stability YANG Module . . . . . . . . . . . . . . . 4
6.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 4
6.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 5
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
7.1. The "IETF XML" Registry . . . . . . . . . . . . . . . . . 9
7.2. The "YANG Module Names" Registry . . . . . . . . . . . . 9
8. Security Consideration . . . . . . . . . . . . . . . . . . . 10
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
11. Normative References . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
The Bidirectional Forwarding Detection ( BFD) [RFC5880] protocol
operates by transmitting and receiving BFD control packets, generally
at high frequency, over the datapath being monitored. In order to
prevent significant data loss due to a datapath failure, BFD session
detection time as defined in BFD [RFC5880] is set to the smallest
feasible value.
This document proposes a mechanism to detect lost packets in a BFD
session in addition to the datapath fault detection mechanisms of
BFD. Such a mechanism presents significant value to measure the
stability of BFD sessions and provides data to the operators for the
cause of a BFD failure.
This document does not propose any BFD extension to measure data
traffic loss or delay on a link or tunnel and the scope is limited to
BFD packets.
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2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in RFC
2119 [RFC2119] and RFC 8174 [RFC8174].
The reader is expected to be familiar with the BFD [RFC5880],
Optimizing BFD Authentication
[I-D.ietf-bfd-optimizing-authentication] and BFD Secure Sequence
Numbers [I-D.ietf-bfd-secure-sequence-numbers].
3. Use Cases
Bidirectional Forwarding Detection as defined in BFD [RFC5880] cannot
detect any BFD packet loss if the loss does not last for detection
time. This document proposes a method to detect a dropped packet on
the receiver. For example, if the receiver receives BFD control
packet k at time t but receives packet k+3 at time t+10ms, and never
receives packet k+1 and/or k+2, then it has experienced a drop.
This proposal enables BFD implementations to generate diagnostic
information on the health of each BFD session that could be used to
preempt a failure on a datapath that BFD was monitoring by allowing
time for a corrective action to be taken.
In a faulty datapath scenario, an operator can use BFD health
information to trigger delay and loss measurement OAM protocol
(Connectivity Fault Management (CFM) or Loss Measurement (LM)-Delay
Measurement (DM)) to further isolate the issue.
4. BFD Null-Authentication Type
The functionality proposed for BFD stability measurement is achieved
by appending an authentication section with the NULL Authentication
type (as defined in Optimizing BFD Authentication
[I-D.ietf-bfd-optimizing-authentication] ) to the BFD control packets
that do not have authentication enabled.
5. Theory of Operation
This mechanism allows operators to measure the loss of BFD control
packets.
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When using MD5 or SHA authentication, BFD uses an authentication
section that carries the Sequence Number. However, if non-meticulous
authentication is being used, or no authentication is in use, then
the non-authenticated BFD control packets MUST include an
authentication section with the NULL Authentication type.
5.1. Loss Measurement
Loss measurement counts the number of BFD control packets missed at
the receiver during any Detection Time period. The loss is detected
by comparing the Sequence Number field in the Auth TLV (NULL or
otherwise) in successive BFD control packets. The Sequence Number in
each successive control packet generated on a BFD session by the
transmitter is incremented by one. This loss count can then be
exposed using the YANG module defined in the subsequent section.
The first BFD authentication section with a non-zero sequence number,
in a valid BFD control packet, processed by the receiver is used for
bootstrapping the logic. When using secure sequence numbers, if the
expected values are pre-calculated, the value must be matched to
detect lost packets as defined in BFD secure sequence numbers
[I-D.ietf-bfd-secure-sequence-numbers].
6. ietf-bfd-stability YANG Module
6.1. Data Model Overview
This YANG module augments the "ietf-bfd" module to add the loss count
to the per-session or lsp for BFD packets that are lost.
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module: ietf-bfd-stability
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh
/bfd-ip-sh:sessions/bfd-ip-sh:session
/bfd-ip-sh:session-statistics:
+--ro lost-packet-count? yang:counter32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd/bfd-ip-mh:ip-mh
/bfd-ip-mh:session-groups/bfd-ip-mh:session-group
/bfd-ip-mh:sessions/bfd-ip-mh:session-statistics:
+--ro lost-packet-count? yang:counter32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd/bfd-lag:lag
/bfd-lag:sessions/bfd-lag:session/bfd-lag:member-links
/bfd-lag:micro-bfd-ipv4/bfd-lag:session-statistics:
+--ro lost-packet-count? yang:counter32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd/bfd-lag:lag
/bfd-lag:sessions/bfd-lag:session/bfd-lag:member-links
/bfd-lag:micro-bfd-ipv6/bfd-lag:session-statistics:
+--ro lost-packet-count? yang:counter32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd/bfd-mpls:mpls
/bfd-mpls:session-groups/bfd-mpls:session-group
/bfd-mpls:sessions/bfd-mpls:session-statistics:
+--ro lost-packet-count? yang:counter32
6.2. YANG Module
This YANG module imports Common YANG Types [RFC6991], A YANG Data
Model for Routing [RFC8349], and YANG Data Model for Bidirectional
Forwading Detection (BFD) [RFC9314].
<CODE BEGINS> file "ietf-bfd-stability@2024-01-23.yang"
module ietf-bfd-stability {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-bfd-stability";
prefix "bfds";
import ietf-yang-types {
prefix "yang";
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-routing {
prefix "rt";
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reference
"RFC 8349: A YANG Data Model for Routing Management
(NMDA version)";
}
import ietf-bfd {
prefix bfd;
reference
"RFC 9314: YANG Data Model for Bidirectional
Forwarding Detection.";
}
import ietf-bfd-ip-sh {
prefix bfd-ip-sh;
reference
"RFC 9314: YANG Data Model for Bidirectional
Forwarding Detection.";
}
import ietf-bfd-ip-mh {
prefix bfd-ip-mh;
reference
"RFC 9314: YANG Data Model for Bidirectional
Forwarding Detection.";
}
import ietf-bfd-lag {
prefix bfd-lag;
reference
"RFC 9314: YANG Data Model for Bidirectional
Forwarding Detection.";
}
import ietf-bfd-mpls {
prefix bfd-mpls;
reference
"RFC 9314: YANG Data Model for Bidirectional
Forwarding Detection.";
}
organization
"IETF BFD Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/bfd>
WG List: <bfd@ietf.org>
Authors: Mahesh Jethanandani (mjethanandani@gmail.com)
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Ashesh Mishra (mishra.ashesh@gmail.com)
Ankur Saxena (ankurpsaxena@gmail.com)
Santosh Pallagatti (santosh.pallagati@gmail.com)
Mach Chen (mach.chen@huawei.com)
Peng Fan (fanp08@gmail.com).";
description
"This YANG module augments the base BFD YANG model to add
attributes related to BFD Stability. In particular it adds a
a per session count for BFD packets that are lost.
Copyright (c) 2024 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.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
'MAY', and 'OPTIONAL' in this document are to be interpreted as
described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.";
revision "2024-01-23" {
description
"Initial Version.";
reference
"RFC XXXX, BFD Stability.";
}
augment "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh/" +
"bfd-ip-sh:sessions/bfd-ip-sh:session/" +
"bfd-ip-sh:session-statistics" {
leaf lost-packet-count {
type yang:counter32;
description
"Number of BFD packets that were lost without bringing the
session down.";
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}
description
"Augment the 'bfd' container to add attributes related to BFD
stability.";
}
augment "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/bfd:bfd/bfd-ip-mh:ip-mh/" +
"bfd-ip-mh:session-groups/bfd-ip-mh:session-group/" +
"bfd-ip-mh:sessions/bfd-ip-mh:session-statistics" {
leaf lost-packet-count {
type yang:counter32;
description
"Number of BFD packets that were lost without bringing the
session down.";
}
description
"Augment the 'bfd' container to add attributes related to BFD
stability.";
}
augment "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/bfd:bfd/bfd-lag:lag/" +
"bfd-lag:sessions/bfd-lag:session/bfd-lag:member-links/" +
"bfd-lag:micro-bfd-ipv4/bfd-lag:session-statistics" {
leaf lost-packet-count {
type yang:counter32;
description
"Number of BFD packets that were lost without bringing the
session down.";
}
description
"Augment the 'bfd' container to add attributes related to BFD
stability.";
}
augment "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/bfd:bfd/bfd-lag:lag/" +
"bfd-lag:sessions/bfd-lag:session/bfd-lag:member-links/" +
"bfd-lag:micro-bfd-ipv6/bfd-lag:session-statistics" {
leaf lost-packet-count {
type yang:counter32;
description
"Number of BFD packets that were lost without bringing the
session down.";
}
description
"Augment the 'bfd' container to add attributes related to BFD
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stability.";
}
augment "/rt:routing/rt:control-plane-protocols/" +
"rt:control-plane-protocol/bfd:bfd/bfd-mpls:mpls/" +
"bfd-mpls:session-groups/bfd-mpls:session-group/" +
"bfd-mpls:sessions/bfd-mpls:session-statistics" {
leaf lost-packet-count {
type yang:counter32;
description
"Number of BFD packets that were lost without bringing the
session down.";
}
description
"Augment the 'bfd' container to add attributes related to BFD
stability.";
}
}
<CODE ENDS>
7. IANA Considerations
7.1. The "IETF XML" Registry
This document registers one URIs in the "ns" subregistry of the "IETF
XML" registry [RFC3688]. Following the format in [RFC3688], the
following registration is requested:
URI: urn:ietf:params:xml:ns:yang:ietf-bfd-stability
Registrant Contact: The IESG
XML: N/A, the requested URI is an XML namespace.
7.2. The "YANG Module Names" Registry
This document registers one YANG modules in the "YANG Module Names"
registry [RFC6020]. Following the format in [RFC6020], the following
registrations are requested:
name: ietf-bfd-stability
namespace: urn:ietf:params:xml:ns:yang:ietf-bfd-stability
prefix: bfds
reference: RFC XXXX
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8. Security Consideration
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 (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.
The YANG module does not define any writeable/creatable/deletable
data nodes.
The only readable data nodes in 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. The model does not define any
readable subtrees and data nodes.
The YANG module does not define any RPC operations.
9. Contributors
Manav Bhatia
10. Acknowledgements
Authors would like to thank Nobo Akiya, Jeffery Haas, Dileep Singh,
Basil Saji, Sagar Soni, Albert Fu and Mallik Mudigonda who also
contributed to this document.
11. Normative References
[I-D.ietf-bfd-optimizing-authentication]
Jethanandani, M., Mishra, A., Saxena, A., and M. Bhatia,
"Optimizing BFD Authentication", Work in Progress,
Internet-Draft, draft-ietf-bfd-optimizing-authentication-
13, 1 August 2021, <https://datatracker.ietf.org/doc/html/
draft-ietf-bfd-optimizing-authentication-13>.
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[I-D.ietf-bfd-secure-sequence-numbers]
DeKok, A., Jethanandani, M., Agarwal, S., Mishra, A., and
A. Saxena, "Secure BFD Sequence Numbers", Work in
Progress, Internet-Draft, draft-ietf-bfd-secure-sequence-
numbers-12, 29 November 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-bfd-
secure-sequence-numbers-12>.
[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/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[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>.
[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>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[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>.
[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/info/rfc8174>.
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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/info/rfc8341>.
[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>.
[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>.
[RFC9314] Jethanandani, M., Ed., Rahman, R., Ed., Zheng, L., Ed.,
Pallagatti, S., and G. Mirsky, "YANG Data Model for
Bidirectional Forwarding Detection (BFD)", RFC 9314,
DOI 10.17487/RFC9314, September 2022,
<https://www.rfc-editor.org/info/rfc9314>.
Authors' Addresses
Ashesh Mishra
SES
Email: mishra.ashesh@gmail.com
Mahesh Jethanandani
Kloud Services
CA
United States of America
Email: mjethanandani@gmail.com
Ankur Saxena
Ciena Corporation
3939 North 1st Street
San Jose, CA 95134
United States of America
Email: ankurpsaxena@gmail.com
URI: www.ciena.com
Santosh Pallagatti
VMware
Bangalore 560103
Karnataka
India
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Email: santosh.pallagatti@gmail.com
Mach Chen
Huawei
Email: mach.chen@huawei.com
Peng Fan
China Mobile
32 Xuanwumen West Street
Beijing
Beijing,
China
Email: fanp08@gmail.com
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