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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Possible downref: Non-RFC (?) normative reference: ref. 'IEEE.802.1AX.2008' ** Obsolete normative reference: RFC 4379 (Obsoleted by RFC 8029) Summary: 1 error (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 RTG Working Group G. Mirsky 3 Internet-Draft ZTE Corp. 4 Updates: 7130 (if approved) J. Tantsura 5 Intended status: Standards Track Individual 6 Expires: September 11, 2017 March 10, 2017 8 Bidirectional Forwarding Detection (BFD) on Multi-chassis Ling 9 Aggregation Group (MC-LAG) Interfaces in IP/MPLS Networks 10 draft-tanmir-rtgwg-bfd-mc-lag-mpls-01 12 Abstract 14 This document describes use of Bidirectional Forwarding Detection for 15 Multi-chassis Link Aggregation Group to provide faster than Link 16 Aggregation Control Protocol convergence. This specification 17 enhances and updates RFC 7130 "Bidirectional Forwarding Detection 18 (BFD) on Link Aggregation Group (LAG) Interfaces". 20 Status of This Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at http://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on September 11, 2017. 37 Copyright Notice 39 Copyright (c) 2017 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (http://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 55 1.1. Conventions used in this document . . . . . . . . . . . . 2 56 1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 2 57 1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3 58 2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3 59 3. BFD on MC-LAG with IP/MPLS data plane . . . . . . . . . . . . 3 60 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 61 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 62 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 63 7. Normative References . . . . . . . . . . . . . . . . . . . . 4 64 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 66 1. Introduction 68 The [RFC7130] defines use of Bidirectional Forwarding Detection (BFD) 69 on Link Aggregation Group (LAG) interfaces. Multi-chassis LAG (MC- 70 LAG) is type of LAG [IEEE.802.1AX.2008] with member links terminated 71 on separate chassis. [IEEE.802.1AX.2008] does not specify MC-LAG but 72 doesn't preclude it either. Link Aggregation Control Protocol 73 (LACP), also defined in [IEEE.802.1AX.2008], can work with MC-LAG 74 but, as in LAG case, can detect link failure only in range of single 75 seconds. This document defines how mechanism defined to work on LAG 76 interfaces [RFC7130] can be adapted to MC-LAG case to enable sub- 77 second detection of member link failure. 79 1.1. Conventions used in this document 81 1.1.1. Terminology 83 ACH: Associated Channel Header 85 BFD: Bidirectional Forwarding Detection 87 BoS: Bottom of the Stack 89 G-ACh: Generic Associated Channel 91 GAL: Generic Associated Label 93 LAG: Link Aggregation Group 95 LACP: Link Aggregation Control Protocol 96 MC-LAG: Multi-chassis Link Aggregation Group 98 MPLS: Multi-Protocol Label Switching 100 1.1.2. Requirements Language 102 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 103 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 104 "OPTIONAL" in this document are to be interpreted as described in 105 [RFC2119]. 107 2. Problem Statement 109 [RFC7130] does not specify selection of the destination IP address 110 for the BFD control packet. The only requirement related to the 111 selection is in Section 2.1 stating that the use of address family 112 across all member links of the given LAG MUST be consistent across 113 all the links. Thus it is implied that the same unicast IP address 114 will be used on all member links of the LAG as use of different 115 destination addresses would defeat the purpose of [RFC7130] 116 transforming the case into set of single-hop BFD sessions [RFC5881]. 117 But single unicast IP address may not work in MC-LAG case as the 118 member links are terminated on the separate chassis. This document 119 proposes how to overcome this problem if using IP or Multi-Protocol 120 Label Switching (MPLS) data plane encapsulation. 122 3. BFD on MC-LAG with IP/MPLS data plane 124 There are more optional encapsulation formats for the case of micro- 125 BFD on MC-LAG over IP/MPLS data plane: 127 o [RFC5586] defined special purpose Generic Associated channel Label 128 (GAL) that MAY be used in MPLS encapsulation of the micro-BFD 129 control packet over MPSL data plane. Depending on the channel 130 type specified in the Associated Channel Header (ACH) that 131 immediately follows after the GAL, micro-BFD MAY use IP/UDP, as 132 displayed in Figure 1 or BFD format, i.e. BFD control packet 133 without IP and UDP headers. 135 0 1 2 3 136 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 1 137 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 138 | GAL | TC |1| TTL | 139 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 140 |0 0 0 1|0 0 0 0| Reserved | IPv4 channel (0x0021) | 141 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 142 | | 143 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 144 | | 145 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 146 | Destination IP address | 147 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 148 | Source IP address | 149 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 150 | UDP header | 151 | | 152 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 153 ~ BFD Control Packet ~ 154 | | 155 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 157 Figure 1: BFD on MC-LAG member link on IPv4/MPLS data plane 159 If IP/UDP format of BFD over MC-LAG interfaces is used, then for IPv4 160 address family the destination IP address MUST be selected from 127/8 161 range [RFC4379], and if IPv6 address family is used, then the 162 destination IP address MUST be selected from 0:0:0:0:0:FFFF:127/104 163 range. 165 4. IANA Considerations 167 This document makes no requests for IANA allocations. This section 168 may be deleted by RFC Editor. 170 5. Security Considerations 172 Security considerations discussed in [RFC7130] apply to this 173 document. 175 6. Acknowledgements 177 7. Normative References 179 [IEEE.802.1AX.2008] 180 "IEEE Standard for Local and metropolitan area networks - 181 Link Aggregation", IEEE 802.1-AX, November 2008. 183 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 184 Requirement Levels", BCP 14, RFC 2119, 185 DOI 10.17487/RFC2119, March 1997, 186 . 188 [RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol 189 Label Switched (MPLS) Data Plane Failures", RFC 4379, 190 DOI 10.17487/RFC4379, February 2006, 191 . 193 [RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed., 194 "MPLS Generic Associated Channel", RFC 5586, 195 DOI 10.17487/RFC5586, June 2009, 196 . 198 [RFC5881] Katz, D. and D. Ward, "Bidirectional Forwarding Detection 199 (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, 200 DOI 10.17487/RFC5881, June 2010, 201 . 203 [RFC7130] Bhatia, M., Ed., Chen, M., Ed., Boutros, S., Ed., 204 Binderberger, M., Ed., and J. Haas, Ed., "Bidirectional 205 Forwarding Detection (BFD) on Link Aggregation Group (LAG) 206 Interfaces", RFC 7130, DOI 10.17487/RFC7130, February 207 2014, . 209 Authors' Addresses 211 Greg Mirsky 212 ZTE Corp. 214 Email: gregimirsky@gmail.com 216 Jeff Tantsura 217 Individual 219 Email: jefftant.ietf@gmail.com