< draft-ietf-bfd-stability-05.txt   draft-ietf-bfd-stability-06.txt >
Network Working Group A. Mishra Network Working Group A. Mishra
Internet-Draft SES Internet-Draft SES
Intended status: Standards Track M. Jethanandani Intended status: Standards Track M. Jethanandani
Expires: August 30, 2020 Expires: January 14, 2021 Kloud Services
A. Saxena A. Saxena
Ciena Corporation Ciena Corporation
S. Pallagatti S. Pallagatti
VmWare VmWare
M. Chen M. Chen
Huawei Huawei
P. Fan P. Fan
China Mobile China Mobile
February 27, 2020 July 13, 2020
BFD Stability BFD Stability
draft-ietf-bfd-stability-05 draft-ietf-bfd-stability-06
Abstract Abstract
This document describes extensions to the Bidirectional Forwarding This document describes extensions to the Bidirectional Forwarding
Detection (BFD) protocol to measure BFD stability. Specifically, it Detection (BFD) protocol to measure BFD stability. Specifically, it
describes a mechanism for detection of BFD frame loss. describes a mechanism for detection of BFD packet loss.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119] .
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 30, 2020. This Internet-Draft will expire on January 14, 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. BFD Null-Authentication TLV . . . . . . . . . . . . . . . . . 3 3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Theory of Operations . . . . . . . . . . . . . . . . . . . . 3 4. BFD Null-Authentication Type . . . . . . . . . . . . . . . . 3
4.1. Loss Measurement . . . . . . . . . . . . . . . . . . . . 3 5. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5.1. Loss Measurement . . . . . . . . . . . . . . . . . . . . 3
6. Security Consideration . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 4 7. Security Consideration . . . . . . . . . . . . . . . . . . . 4
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 4
9. Normative References . . . . . . . . . . . . . . . . . . . . 4 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 10. Normative References . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction 1. Introduction
The Bidirectional Forwarding Detection ( BFD) [RFC5880] protocol The Bidirectional Forwarding Detection ( BFD) [RFC5880] protocol
operates by transmitting and receiving control frames, generally at operates by transmitting and receiving BFD control packets, generally
high frequency, over the datapath being monitored. In order to at high frequency, over the datapath being monitored. In order to
prevent significant data loss due to a datapath failure, the prevent significant data loss due to a datapath failure, BFD session
tolerance for lost or delayed frames in the Detection Time, as detection time as defined in BFD [RFC5880] is set to the smallest
defined in BFD [RFC5880] is set to the smallest feasible value. feasible value.
This document proposes a mechanism to detect lost frames in a BFD This document proposes a mechanism to detect lost packet in a BFD
session in addition to the datapath fault detection mechanisms of session in addition to the datapath fault detection mechanisms of
BFD. Such a mechanism presents significant value to measure the BFD. Such a mechanism presents significant value to measure the
stability of BFD sessions and provides data to the operators for the stability of BFD sessions and provides data to the operators for the
cause of a BFD failure. cause of a BFD failure.
This document does not propose BFD extension to measure data traffic This document does not propose any BFD extension to measure data
loss or delay on a link or tunnel and the scope is limited to BFD traffic loss or delay on a link or tunnel and the scope is limited to
frames. BFD packets.
2. Use Cases 2. Terminology
Legacy BFD cannot detect any BFD frame loss if loss does not last for The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
dead interval. This draft proposes a method to detect a dropped "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
frame on the receiver. For example, if the receiver receives BFD CC document are to be interpreted as described in RFC 2119 [RFC2119] and
frame k at time t but receives frame k+3 at time t+10ms, and never RFC 8174 [RFC8174].
receives frame k+1 and/or k+2, then it has experienced a drop.
This proposal enables BFD engine to generate diagnostic information The reader is expected to be familiar with the BFD [RFC5880],
on the health of each BFD session that could be used to preempt a Optimizing BFD Authentication
failure on a link that BFD was monitoring by allowing time for a [I-D.ietf-bfd-optimizing-authentication] and BFD Secure Sequence
corrective action to be taken. Numbers [I-D.ietf-bfd-secure-sequence-numbers].
In a faulty datapath scenario, operator can use BFD health 3. Use Cases
Bidirectional Forwarding Detection as defined in BFD [RFC5880] cannot
detect any BFD packet loss if 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 implementation to generate diagnostic
information on the health of each BFD session that could be used to
preempt a failure on a link 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 information to trigger delay and loss measurement OAM protocol
(Connectivity Fault Management (CFM) or Loss Measurement (LM)-Delay (Connectivity Fault Management (CFM) or Loss Measurement (LM)-Delay
Measurement (DM)) to further isolate the issue. Measurement (DM)) to further isolate the issue.
3. BFD Null-Authentication TLV 4. BFD Null-Authentication Type
The functionality proposed for BFD stability measurement is achieved The functionality proposed for BFD stability measurement is achieved
by appending the Null-Authentication TLV (as defined in Optimizing by appending the Null-Authentication type (as defined in Optimizing
BFD Authentication [I-D.ietf-bfd-optimizing-authentication] ) to the BFD Authentication [I-D.ietf-bfd-optimizing-authentication] ) to the
BFD control frame that do not have authentication enabled. BFD control packets that do not have authentication enabled.
4. Theory of Operations 5. Theory of Operation
This mechanism allows operator to measure the loss of BFD CC frames. This mechanism allows operators to measure the loss of BFD control
packets.
When using MD5 or SHA authentication, BFD uses authentication TLV When using MD5 or SHA authentication, BFD uses authentication TLV
that carries the Sequence Number. However, if non-meticulous that carries the Sequence Number. However, if non-meticulous
authentication is being used, or no authentication is in use, then authentication is being used, or no authentication is in use, then
the non-authenticated BFD frames MUST include NULL-Auth TLV. the non-authenticated BFD packets MUST include NULL-Auth TLV.
4.1. Loss Measurement 5.1. Loss Measurement
Loss measurement counts the number of BFD control frames missed at Loss measurement counts the number of BFD control packets missed at
the receiver during any Detection Time period. The loss is detected the receiver during any Detection Time period. The loss is detected
by comparing the Sequence Number field in the Auth TLV (NULL or by comparing the Sequence Number field in the Auth TLV (NULL or
otherwise) in successive BFD CC frames. The Sequence Number in each otherwise) in successive BFD control packets. The Sequence Number in
successive control frame generated on a BFD session by the each successive control packet generated on a BFD session by the
transmitter is incremented by one. transmitter is incremented by one.
The first BFD NULL-Auth TLV processed by the receiver that has a non- The first BFD NULL-Auth type processed by the receiver that has a
zero sequence number is used for bootstrapping the logic. When using non-zero sequence number is used for bootstrapping the logic. When
secure sequence numbers, if the expected values are pre-calculated, using secure sequence numbers, if the expected values are pre-
the matched value must be appropriately recorded to detect lost calculated, the value must be matched to detect lost packets as
frames. defined in BFD secure sequence numbers
[I-D.ietf-bfd-secure-sequence-numbers].
5. IANA Considerations 6. IANA Considerations
This document has no actions for IANA. This document has no actions for IANA.
6. Security Consideration 7. Security Consideration
Other than concerns raised in BFD [RFC5880] there are no new concerns Other than concerns raised in BFD [RFC5880], Optimizing BFD
with this proposal. Authentication [I-D.ietf-bfd-optimizing-authentication] and BFD
Secure Sequence Numbers [I-D.ietf-bfd-secure-sequence-numbers].
There are no new concerns with this proposal.
7. Contributors 8. Contributors
Manav Bhatia Manav Bhatia
8. Acknowledgements 9. Acknowledgements
Authors would like to thank Nobo Akiya, Jeffery Haas, Peng Fan, Authors would like to thank Nobo Akiya, Jeffery Haas, Peng Fan,
Dileep Singh, Basil Saji, Sagar Soni and Mallik Mudigonda who also Dileep Singh, Basil Saji, Sagar Soni and Mallik Mudigonda who also
contributed to this document. contributed to this document.
9. Normative References 10. Normative References
[I-D.ietf-bfd-optimizing-authentication] [I-D.ietf-bfd-optimizing-authentication]
Jethanandani, M., Mishra, A., Saxena, A., and M. Bhatia, Jethanandani, M., Mishra, A., Saxena, A., and M. Bhatia,
"Optimizing BFD Authentication", draft-ietf-bfd- "Optimizing BFD Authentication", draft-ietf-bfd-
optimizing-authentication-09 (work in progress), December optimizing-authentication-09 (work in progress), December
2019. 2019.
[I-D.ietf-bfd-secure-sequence-numbers]
Jethanandani, M., Agarwal, S., Mishra, A., Saxena, A., and
A. DeKok, "Secure BFD Sequence Numbers", draft-ietf-bfd-
secure-sequence-numbers-05 (work in progress), February
2020.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
(BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010,
<https://www.rfc-editor.org/info/rfc5880>. <https://www.rfc-editor.org/info/rfc5880>.
[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>.
Authors' Addresses Authors' Addresses
Ashesh Mishra Ashesh Mishra
SES SES
Email: mishra.ashesh@gmail.com Email: mishra.ashesh@gmail.com
Mahesh Jethanandani Mahesh Jethanandani
Kloud Services
CA CA
USA USA
Email: mjethanandani@gmail.com Email: mjethanandani@gmail.com
Ankur Saxena Ankur Saxena
Ciena Corporation Ciena Corporation
3939 North 1st Street 3939 North 1st Street
San Jose, CA 95134 San Jose, CA 95134
USA USA
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