draft-ietf-bfd-seamless-ip-04.txt   draft-ietf-bfd-seamless-ip-05.txt 
Internet Engineering Task Force N. Akiya Internet Engineering Task Force N. Akiya
Internet-Draft Big Switch Networks Internet-Draft Big Switch Networks
Intended status: Standards Track C. Pignataro Intended status: Standards Track C. Pignataro
Expires: October 15, 2016 D. Ward Expires: November 5, 2016 D. Ward
Cisco Systems Cisco
April 13, 2016 May 4, 2016
Seamless Bidirectional Forwarding Detection (S-BFD) for Seamless Bidirectional Forwarding Detection (S-BFD) for
IPv4, IPv6 and MPLS IPv4, IPv6 and MPLS
draft-ietf-bfd-seamless-ip-04 draft-ietf-bfd-seamless-ip-05
Abstract Abstract
This document defines procedures to use Seamless Bidirectional This document defines procedures to use Seamless Bidirectional
Forwarding Detection (S-BFD) for IPv4, IPv6 and MPLS environments. Forwarding Detection (S-BFD) for IPv4, IPv6 and MPLS environments.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
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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-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
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 October 15, 2016. This Internet-Draft will expire on November 5, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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3. S-BFD Echo UDP Port . . . . . . . . . . . . . . . . . . . . . 3 3. S-BFD Echo UDP Port . . . . . . . . . . . . . . . . . . . . . 3
4. S-BFD Control Packet Demultiplexing . . . . . . . . . . . . . 3 4. S-BFD Control Packet Demultiplexing . . . . . . . . . . . . . 3
5. Initiator Procedures . . . . . . . . . . . . . . . . . . . . 3 5. Initiator Procedures . . . . . . . . . . . . . . . . . . . . 3
5.1. Details of S-BFD Control Packet Sent by SBFDInitiator . . 4 5.1. Details of S-BFD Control Packet Sent by SBFDInitiator . . 4
5.1.1. Target vs. Remote Entity (S-BFD Discriminator) . . . 4 5.1.1. Target vs. Remote Entity (S-BFD Discriminator) . . . 4
6. Responder Procedures . . . . . . . . . . . . . . . . . . . . 5 6. Responder Procedures . . . . . . . . . . . . . . . . . . . . 5
6.1. Details of S-BFD Control Packet Sent by SBFDReflector . . 5 6.1. Details of S-BFD Control Packet Sent by SBFDReflector . . 5
7. Security Considerations . . . . . . . . . . . . . . . . . . . 5 7. Security Considerations . . . . . . . . . . . . . . . . . . . 5
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
10. Contributing Authors . . . . . . . . . . . . . . . . . . . . 6 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 6
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
11.1. Normative References . . . . . . . . . . . . . . . . . . 7 11.1. Normative References . . . . . . . . . . . . . . . . . . 7
11.2. Informative References . . . . . . . . . . . . . . . . . 7 11.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
Seamless Bidirectional Forwarding Detection (S-BFD), Seamless Bidirectional Forwarding Detection (S-BFD),
[I-D.ietf-bfd-seamless-base], defines a generalized mechanism to [I-D.ietf-bfd-seamless-base], defines a generalized mechanism to
allow network nodes to seamlessly perform continuity checks to remote allow network nodes to seamlessly perform continuity checks to remote
entities. This document defines necessary procedures to use S-BFD on entities. This document defines necessary procedures to use S-BFD on
IPv4, IPv6 and MPLS environments. IPv4, IPv6 and MPLS environments.
The reader is expected to be familiar with the IP [RFC0791] The reader is expected to be familiar with the IP [RFC0791]
[RFC2460], BFD [RFC5880], MPLS BFD [RFC5884], and S-BFD [RFC2460], BFD [RFC5880], MPLS BFD [RFC5884], and S-BFD
[I-D.ietf-bfd-seamless-base] terminologies and protocol constructs. [I-D.ietf-bfd-seamless-base] terminologies and protocol constructs.
2. S-BFD UDP Port 2. S-BFD UDP Port
A new UDP port is defined for the use of the S-BFD on IPv4, IPv6 and A new UDP port is defined for the use of the S-BFD on IPv4, IPv6 and
MPLS environments: 7784. SBFDReflector session MUST listen for MPLS environments: 7784.
incoming S-BFD control packets on the port 7784. SBFDInitiator
sessions MUST transmit S-BFD control packets with destination port On S-BFD control packets from the SBFDInitiator to the SBFDReflector,
7784. The source port of the S-BFD control packets transmitted by the SBFDReflector session MUST listen for incoming S-BFD control
SBFDInitiator sessions can be any but MUST NOT be 7784. The same UDP packets on the port 7784. SBFDInitiator sessions MUST transmit S-BFD
source port number MUST be used for all S-BFD control packets control packets with destination port 7784. The source port of the
associated with a particular SBFDInitiator session. The source port S-BFD control packets transmitted by SBFDInitiator sessions can be
number is unique among all SBFDInitiator sessions on the system. any but MUST NOT be 7784. The same UDP source port number MUST be
used for all S-BFD control packets associated with a particular
SBFDInitiator session. The source port number is unique among all
SBFDInitiator sessions on the system.
On S-BFD control packets from the SBFDReflecto to the SBFDInitiator,
the SBFDInitiator MUST listen for reflected S-BFD control packets at
its source port.
3. S-BFD Echo UDP Port 3. S-BFD Echo UDP Port
The BFD Echo port defined by [RFC5881], port 3785, is used for the The BFD Echo port defined by [RFC5881], port 3785, is used for the
S-BFD Echo function on IPv4, IPv6 and MPLS environments. S-BFD Echo function on IPv4, IPv6 and MPLS environments.
SBFDInitiator sessions MUST transmit S-BFD echo packets with SBFDInitiator sessions MUST transmit S-BFD echo packets with
destination port 3785. This document defines only the UDP port value destination port 3785. The setting of the UDP source port [RFC5881]
for the S-BFD Echo function. The source port and the procedures for and the procedures [I-D.ietf-bfd-seamless-base] for the S-BFD Echo
the S-BFD Echo function are outside the scope of this document. function are outside the scope of this document.
4. S-BFD Control Packet Demultiplexing 4. S-BFD Control Packet Demultiplexing
The S-BFD Control Packet demultiplexing follows the procedure The S-BFD Control Packet demultiplexing follows the procedure
specified in Section 7.1. of [I-D.ietf-bfd-seamless-base]. Received specified in Section 7.1. of [I-D.ietf-bfd-seamless-base]. Received
S-BFD control packet MUST be demultiplexed with the destination UDP S-BFD control packet MUST be demultiplexed with the destination UDP
port field. port field.
This procedure for an S-BFD packet is executed on both the initiator This procedure for an S-BFD packet is executed on both the initiator
and the reflector. If the port is 7784 (i.e., S-BFD packet for and the reflector. If the port is 7784 (i.e., S-BFD packet for
S-BFDReflector)), then the packet MUST be looked up to locate a S-BFDReflector), then the packet MUST be looked up to locate a
corresponding SBFDReflector session based on the value from the "your corresponding SBFDReflector session based on the value from the "your
discriminator" field in the table describing S-BFD discriminators. discriminator" field in the table describing S-BFD discriminators.
If the port is not 7784, then the packet MUST be looked up to locate If the port is not 7784, but the packet is demultiplexed to be for an
a corresponding SBFDInitiator session or classical BFD session based SBFDInitiator, then the packet MUST be looked up to locate a
on the value from the "your discriminator" field in the table corresponding SBFDInitiator session based on the value from the "your
describing BFD discriminators. If the located session is an discriminator" field in the table describing BFD discriminators. In
SBFDInitiator, then the destination IP address of the packet SHOULD that case, then the destination IP address of the packet SHOULD be
be validated to be for self. If the packet is a classical BFD validated to be for itself. If the packet demultiplexes to a
session, then the procedures from [RFC5880] apply. classical BFD session, then the procedures from [RFC5880] apply.
5. Initiator Procedures 5. Initiator Procedures
S-BFD control packets are transmitted with IP header, UDP header and S-BFD control packets are transmitted with IP header, UDP header and
BFD control header ([RFC5880]). When S-BFD control packets are BFD control header ([RFC5880]). When S-BFD control packets are
explicitly label switched (i.e. not IP routed which happen to go over explicitly label switched (i.e. not IP routed which happen to go over
an LSP, but explicitly sent on a specific LSP), the former is an LSP, but explicitly sent on a specific LSP), the former is
prepended with a label stack. Note that this document does not make prepended with a label stack. Note that this document does not make
a distinction between a single-hop S-BFD scenario and a multi-hop a distinction between a single-hop S-BFD scenario and a multi-hop
S-BFD scenario, both scenarios are supported. S-BFD scenario, both scenarios are supported.
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as with [RFC5884]. as with [RFC5884].
* TTL field of the IP header MUST be set to 1. * TTL field of the IP header MUST be set to 1.
5.1.1. Target vs. Remote Entity (S-BFD Discriminator) 5.1.1. Target vs. Remote Entity (S-BFD Discriminator)
Typically, an S-BFD control packet will have "your discriminator" Typically, an S-BFD control packet will have "your discriminator"
field corresponding to an S-BFD discriminator of the remote entity field corresponding to an S-BFD discriminator of the remote entity
located on the target network node defined by the destination IP located on the target network node defined by the destination IP
address or the label stack. It is, however, possible for an address or the label stack. It is, however, possible for an
SBFDInitiator to carefully set "your discriminator" and TTL fields to SBFDInitiator to carefully set the "your discriminator" and TTL
perform a continuity test towards a target, but to a transit network fields to perform a continuity test in the direction towards a
node and not to the target itself. target, but destined to a transit network node and not to the target
itself.
Section 5.1 intentionally uses the word "target", instead of "remote Section 5.1 intentionally uses the word "target", instead of "remote
entity", to accommodate this possible S-BFD usage through TTL expiry. entity", to accommodate this possible S-BFD usage through TTL expiry.
This also requires S-BFD control packets not be dropped by the This also requires S-BFD control packets not be dropped by the
responder node due to TTL expiry. Thus implementations on the responder node due to TTL expiry. Thus implementations on the
responder MUST allow received S-BFD control packets taking TTL expiry responder MUST allow received S-BFD control packets taking TTL expiry
exception path to reach corresponding reflector BFD session. exception path to reach corresponding reflector BFD session.
6. Responder Procedures 6. Responder Procedures
S-BFD control packets are IP routed back to the initiator, and will S-BFD control packets are IP routed back to the initiator, and will
have IP header, UDP header and BFD control header. If an have IP header, UDP header and BFD control header. If an
SBFDReflector receives an S-BFD control packet with UDP source port SBFDReflector receives an S-BFD control packet with UDP source port
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A new value 7784 was allocated from the "Service Name and Transport A new value 7784 was allocated from the "Service Name and Transport
Protocol Port Number Registry". The allocated registry entry is: Protocol Port Number Registry". The allocated registry entry is:
Service Name (REQUIRED) Service Name (REQUIRED)
s-bfd s-bfd
Transport Protocol(s) (REQUIRED) Transport Protocol(s) (REQUIRED)
udp udp
Assignee (REQUIRED) Assignee (REQUIRED)
IESG <iesg@ietf.org> IESG <iesg@ietf.org>
Contact (REQUIRED) Contact (REQUIRED)
BFD Chairs <bfd-chairs@tools.ietf.org> BFD Chairs <bfd-chairs@ietf.org>
Description (REQUIRED) Description (REQUIRED)
Seamless Bidirectional Forwarding Detection (S-BFD) Seamless Bidirectional Forwarding Detection (S-BFD)
Reference (REQUIRED) Reference (REQUIRED)
RFC.this (RFC Editor, please update at publication) RFC.this (RFC Editor, please update at publication)
Port Number (OPTIONAL) Port Number (OPTIONAL)
7784 7784
9. Acknowledgements 9. Acknowledgements
The authors would like to thank the BFD WG members for helping to The authors would like to thank the BFD WG members for helping to
shape the contents of this document. In particular, significant shape the contents of this document. In particular, significant
contributions were made by following people: Marc Binderberger, contributions were made by following people: Marc Binderberger,
Jeffrey Haas, Santosh Pallagatti, Greg Mirsky, Sam Aldrin, Vengada Jeffrey Haas, Santosh Pallagatti, Greg Mirsky, Sam Aldrin, Vengada
Prasad Govindan, Mallik Mudigonda and Srihari Raghavan. Prasad Govindan, Mallik Mudigonda and Srihari Raghavan.
10. Contributing Authors 10. Contributors
Tarek Saad
Cisco Systems
Email: tsaad@cisco.com
Siva Sivabalan The following are key contributors to this document:
Cisco Systems
Email: msiva@cisco.com
Nagendra Kumar Tarek Saad, Cisco Systems, Inc.
Cisco Systems Siva Sivabalan, Cisco Systems, Inc.
Email: naikumar@cisco.com Nagendra Kumar, Cisco Systems, Inc.
11. References 11. References
11.1. Normative References 11.1. Normative References
[I-D.ietf-bfd-seamless-base] [I-D.ietf-bfd-seamless-base]
Akiya, N., Pignataro, C., Ward, D., Bhatia, M., and J. Akiya, N., Pignataro, C., Ward, D., Bhatia, M., and J.
Networks, "Seamless Bidirectional Forwarding Detection Networks, "Seamless Bidirectional Forwarding Detection
(S-BFD)", draft-ietf-bfd-seamless-base-08 (work in (S-BFD)", draft-ietf-bfd-seamless-base-09 (work in
progress), February 2016. progress), April 2016.
[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,
<http://www.rfc-editor.org/info/rfc2119>. <http://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,
<http://www.rfc-editor.org/info/rfc5880>. <http://www.rfc-editor.org/info/rfc5880>.
skipping to change at page 8, line 13 skipping to change at page 8, line 13
June 2010, <http://www.rfc-editor.org/info/rfc5884>. June 2010, <http://www.rfc-editor.org/info/rfc5884>.
Authors' Addresses Authors' Addresses
Nobo Akiya Nobo Akiya
Big Switch Networks Big Switch Networks
Email: nobo.akiya.dev@gmail.com Email: nobo.akiya.dev@gmail.com
Carlos Pignataro Carlos Pignataro
Cisco Systems Cisco Systems, Inc.
Email: cpignata@cisco.com Email: cpignata@cisco.com
Dave Ward Dave Ward
Cisco Systems Cisco Systems, Inc.
Email: wardd@cisco.com Email: wardd@cisco.com
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