Unaffiliated BFD Echo Function
draft-ietf-bfd-unaffiliated-echo-01
BFD Working Group W. Cheng
Internet-Draft R. Wang
Updates: 5880 (if approved) China Mobile
Intended status: Standards Track X. Min
Expires: May 6, 2021 ZTE Corp.
R. Rahman
Cisco Systems
R. Boddireddy
Juniper Networks
November 2, 2020
Unaffiliated BFD Echo Function
draft-ietf-bfd-unaffiliated-echo-01
Abstract
Bidirectional Forwarding Detection (BFD) is a fault detection
protocol that can quickly determine a communication failure between
two forwarding engines. This document proposes a use of the BFD Echo
function where the local system supports BFD but the neighboring
system does not support BFD.
Status of This Memo
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This Internet-Draft will expire on May 6, 2021.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Updates to RFC 5880 . . . . . . . . . . . . . . . . . . . . . 3
3. Unaffiliated BFD Echo Procedures . . . . . . . . . . . . . . 6
4. Unaffilicated BFD Echo Applicability . . . . . . . . . . . . 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . 8
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
To minimize the impact of device/link faults on services and improve
network availability, a network device must be able to quickly detect
faults in communication with adjacent devices. Measures can then be
taken to promptly rectify the faults to ensure service continuity.
BFD [RFC5880] is a low-overhead, short-duration method to detect
faults on the communication path between adjacent forwarding engines.
The faults can be on interface, data link, and even forwarding
engine. It is a single, unified mechanism to monitor any media and
protocol layers in real time.
BFD defines Asynchronous mode to satisfy various deployment
scenarios, and also supports Echo function to reduce the device
requirement for BFD. When the Echo function is activated, the local
system sends BFD Echo packets and the remote system loops back the
received Echo packets through the forwarding path. If several
consecutive BFD Echo packets are not received by the local system,
then the BFD session is declared to be Down.
When using BFD Echo function, there are two typical scenarios as
below:
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o Full BFD protocol capability with affiliated Echo function: this
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