Bidirectional Forwarding Detection (BFD)
RFC 5880
| Document | Type |
RFC - Proposed Standard
(June 2010; Errata)
Was draft-ietf-bfd-base (bfd WG)
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 5880 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Adrian Farrel | ||
| Send notices to | (None) | ||
Internet Engineering Task Force (IETF) D. Katz
Request for Comments: 5880 D. Ward
Category: Standards Track Juniper Networks
ISSN: 2070-1721 June 2010
Bidirectional Forwarding Detection (BFD)
Abstract
This document describes a protocol intended to detect faults in the
bidirectional path between two forwarding engines, including
interfaces, data link(s), and to the extent possible the forwarding
engines themselves, with potentially very low latency. It operates
independently of media, data protocols, and routing protocols.
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 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5880.
Copyright Notice
Copyright (c) 2010 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
(http://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.
Katz & Ward Standards Track [Page 1]
RFC 5880 Bidirectional Forwarding Detection June 2010
Table of Contents
1. Introduction ....................................................3
1.1. Conventions Used in This Document ..........................4
2. Design ..........................................................4
3. Protocol Overview ...............................................5
3.1. Addressing and Session Establishment .......................5
3.2. Operating Modes ............................................5
4. BFD Control Packet Format .......................................7
4.1. Generic BFD Control Packet Format ..........................7
4.2. Simple Password Authentication Section Format .............11
4.3. Keyed MD5 and Meticulous Keyed MD5 Authentication
Section Format ............................................11
4.4. Keyed SHA1 and Meticulous Keyed SHA1
Authentication Section Format .............................13
5. BFD Echo Packet Format .........................................14
6. Elements of Procedure ..........................................14
6.1. Overview ..................................................14
6.2. BFD State Machine .........................................16
6.3. Demultiplexing and the Discriminator Fields ...............17
6.4. The Echo Function and Asymmetry ...........................18
6.5. The Poll Sequence .........................................19
6.6. Demand Mode ...............................................19
6.7. Authentication ............................................21
6.7.1. Enabling and Disabling Authentication ..............21
6.7.2. Simple Password Authentication .....................22
6.7.3. Keyed MD5 and Meticulous Keyed MD5 Authentication ..23
6.7.4. Keyed SHA1 and Meticulous Keyed SHA1
Authentication .....................................25
6.8. Functional Specifics ......................................27
6.8.1. State Variables ....................................27
6.8.2. Timer Negotiation ..................................30
6.8.3. Timer Manipulation .................................31
6.8.4. Calculating the Detection Time .....................32
6.8.5. Detecting Failures with the Echo Function ..........33
6.8.6. Reception of BFD Control Packets ...................33
6.8.7. Transmitting BFD Control Packets ...................36
6.8.8. Reception of BFD Echo Packets ......................39
6.8.9. Transmission of BFD Echo Packets ...................39
6.8.10. Min Rx Interval Change ............................40
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