Routing Working Group A. Mishra Internet-Draft M. Jethanandani Intended status: Standards Track A. Saxena Expires: October 25, 2015 Ciena Corporation S. Pallagatti Juniper Networks M. Chen Huawei April 23, 2015 BFD Stability draft-ashesh-bfd-stability-02.txt 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 frame 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. 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 http://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 October 25, 2015. Mishra, et al. Expires October 25, 2015 [Page 1] Internet-Draft BFD Stability April 2015 Copyright Notice Copyright (c) 2015 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. BFD Null-Authentication TLV . . . . . . . . . . . . . . . . . 2 3. Theory of Operations . . . . . . . . . . . . . . . . . . . . 3 4. IANA Requirements . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Consideration . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 7. Normative References . . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction The Bidirectional Forwarding Detection (BFD) protocol operates by transmitting and receiving control frames, generally at high frequency, over the datapath being monitored. In order to prevent significant data loss due to a datapath failure, the tolerance for lost or delayed frames (the Detection Time as described in RFC 5880) is set to the smallest feasible value. This document proposes a mechanism to detect lost frames in a BFD session in addition to the datapath fault detection mechanisms of BFD. Such a mechanism presents significant value with the ability to measure the stability of BFD sessions and provides data to the operators. 2. BFD Null-Authentication TLV The functionality proposed for BFD stability measurement is achieved by appending the Null-Authentication TLV to the BFD control frame. The Null-Authentication TLV (called 0-Auth in this document) extends the existing BFD Authentication TLV structure by adding a new Auth- Mishra, et al. Expires October 25, 2015 [Page 2] Internet-Draft BFD Stability April 2015 Type of . This TLV carries the Sequence Number for frame loss measurement. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Auth Type | Auth Len | Auth Key ID | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved for Future | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved for Future | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: Auth Type: The Authentication Type, which in this case is (Null Authentication). Auth Len: The length of the Authentication Section, in bytes. Set to 12. Auth Key ID: The Authentication Key ID in use for this packet. This MUST be set to zero on transmit, and ignored on receipt. Reserved: This byte MUST be set to zero on transmit, and ignored on receipt. Reserved for Future: For future extensions. MUST be set to 0 if not used. Sequence Number: This indicates the sequence number for this packet and MUST be present in every 0-Auth TLV. This value is incremented by 1 for every frame transmitted while the session state is UP. A value of 0 indicates a request by sender to reset the sequence number correlation logic at the receiver. The first frame transmitted by the sender MAY set this field to 0. 3. Theory of Operations This mechanism allows operator to measure the loss of BFD CC frames. This measurement counts the number of BFD control frames missed at the receiver due to a transient change in the network such as congestion. Frame-loss is detected by comparing the Sequence Number field in the 0-Auth TLV in successive BFD CC frames. The Sequence Mishra, et al. Expires October 25, 2015 [Page 3] Internet-Draft BFD Stability April 2015 Number in each successive control frame generated on a BFD session by the transmitter is incremented by one. The first BFD Loss-Delay TLV processed by the receiver that has a non-zero sequence number is used for bootstrapping the logic. Each successive frame after this is expected to have a Sequence Number that is one greater than the Sequence Number in the previous frame. 4. IANA Requirements IANA is requested to assign new Auth-Type for the Null-Authentication TLV for BFD Stability Measurement. The following number is suggested. Value Meaning 6 Null-Authentication TLV 5. Security Consideration Since this method uses an authentication TLV to achive the functionality, usage of this TLV will prevent the use of other authentication TLVs. 6. Acknowledgements Nobo Akiya, Jeffery Haas, Peng Fan, Dileep Singh, Basil Saji, Sagar Soni and Mallik Mudigonda also conributed to this document. 7. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, June 2010. Authors' Addresses Ashesh Mishra Ciena Corporation 3939 North 1st Street San Jose, CA 95134 USA Email: mishra.ashesh@gmail.com URI: www.ciena.com Mishra, et al. Expires October 25, 2015 [Page 4] Internet-Draft BFD Stability April 2015 Mahesh Jethanandani Ciena Corporation 3939 North 1st Street San Jose, CA 95134 USA Email: mjethanandani@gmail.com URI: www.ciena.com Ankur Saxena Ciena Corporation 3939 North 1st Street San Jose, CA 95134 USA Email: ankurpsaxena@gmail.com Santosh Pallagatti Juniper Networks Juniper Networks, Exora Business Park Bangalore, Karnataka 560103 India Phone: + Email: santoshpk@juniper.net Mach Chen Huawei Email: mach.chen@huawei.com Mishra, et al. Expires October 25, 2015 [Page 5]