idnits 2.17.1 draft-chen-spring-segemt-routing-anycast-frr-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document doesn't use any RFC 2119 keywords, yet seems to have RFC 2119 boilerplate text. -- The document date (December 05, 2017) is 2335 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Unused Reference: 'I-D.ietf-isis-segment-routing-extensions' is defined on line 159, but no explicit reference was found in the text == Unused Reference: 'I-D.ietf-ospf-ospfv3-segment-routing-extensions' is defined on line 165, but no explicit reference was found in the text == Unused Reference: 'I-D.ietf-ospf-segment-routing-extensions' is defined on line 172, but no explicit reference was found in the text == Unused Reference: 'RFC2119' is defined on line 184, but no explicit reference was found in the text == Unused Reference: 'RFC3031' is defined on line 189, but no explicit reference was found in the text == Outdated reference: A later version (-25) exists of draft-ietf-isis-segment-routing-extensions-13 == Outdated reference: A later version (-23) exists of draft-ietf-ospf-ospfv3-segment-routing-extensions-10 == Outdated reference: A later version (-27) exists of draft-ietf-ospf-segment-routing-extensions-22 == Outdated reference: A later version (-15) exists of draft-ietf-spring-segment-routing-13 Summary: 1 error (**), 0 flaws (~~), 11 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Networking Working Group Ran. Chen 3 Internet-Draft Shaofu. Peng 4 Intended status: Standards Track ZTE Corporation 5 Expires: June 8, 2018 December 05, 2017 7 Anycast-SID FRR for Segment Routing Network 8 draft-chen-spring-segemt-routing-anycast-frr-00 10 Abstract 12 This document specifies the fast redundancy protection mechanism, 13 aimed at providing protection of the domain boundary nodes in Cross 14 domain scenario. 16 Status of This Memo 18 This Internet-Draft is submitted in full conformance with the 19 provisions of BCP 78 and BCP 79. 21 Internet-Drafts are working documents of the Internet Engineering 22 Task Force (IETF). Note that other groups may also distribute 23 working documents as Internet-Drafts. The list of current Internet- 24 Drafts is at https://datatracker.ietf.org/drafts/current/. 26 Internet-Drafts are draft documents valid for a maximum of six months 27 and may be updated, replaced, or obsoleted by other documents at any 28 time. It is inappropriate to use Internet-Drafts as reference 29 material or to cite them other than as "work in progress." 31 This Internet-Draft will expire on June 8, 2018. 33 Copyright Notice 35 Copyright (c) 2017 IETF Trust and the persons identified as the 36 document authors. All rights reserved. 38 This document is subject to BCP 78 and the IETF Trust's Legal 39 Provisions Relating to IETF Documents 40 (https://trustee.ietf.org/license-info) in effect on the date of 41 publication of this document. Please review these documents 42 carefully, as they describe your rights and restrictions with respect 43 to this document. Code Components extracted from this document must 44 include Simplified BSD License text as described in Section 4.e of 45 the Trust Legal Provisions and are provided without warranty as 46 described in the Simplified BSD License. 48 Table of Contents 50 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 51 2. Conventions used in this document . . . . . . . . . . . . . . 2 52 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 2 53 4. Anycast-SID FRR Solution . . . . . . . . . . . . . . . . . . 2 54 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 55 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 56 7. Normative references . . . . . . . . . . . . . . . . . . . . 4 57 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 59 1. Introduction 61 This document specifies the fast redundancy protection mechanism, 62 aimed at providing protection of the domain boundary nodes in Cross 63 domain scenario. 65 2. Conventions used in this document 67 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 68 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 69 document are to be interpreted as described in RFC2119. 71 3. Motivation 73 The procedures specified in this document, in combination with 74 [I-D.ietf-spring-segment-routing] provide the fast redundancy 75 protection. 77 The procedures specified in this document aims at providing 78 protection of the domain boundary nodes in Cross domain scenario. 80 4. Anycast-SID FRR Solution 82 The solution consists of three parts. 84 o Configure the same anycast prefix and associated prefix-sid for 85 each domain boundary node that forms redundant protection, then 86 the anycast prefix and associated prefix-sid with Anycast-Group 87 flag should be advertised to the neighbor node. 89 o Create the anycast-group forwarding entry (i.e. FRR entry) after 90 the direct neighbor node of the domain boundary nodes receive the 91 prefix-sid with Anycast-Group flag advertisement. The anycast- 92 group forwarding entry includes the forwarding information which 93 points to each of the domain boundary node , then the forwarding 94 entry pointing to the main domain boundary (one of the direct 95 connected boundary nodes from the PLR) is set to the active state, 96 and others are set to the backup state. Only the direct neighbor 97 of the domain boundary nodes need to set up the anycast-group 98 forwarding entry. 100 o if the neighbor node detects the main domain boundary node 101 failure, the neighbor node immediately activates the backup entry. 102 Note that the backup entry contains the node-sid of the slave 103 boundary node, and the packet will be forwarded based on the node- 104 sid, not the anycast prefix-sid again. 106 +-----------------------+ +---------------+ +------------------+ 107 | SID:20 SID:30 | | | | SID:60 | 108 | A2-----A3------GW11------C1------GW21------A6 | 109 | / \ / | |\ / \ /| | \ | 110 | / \ / | | \ / \ / | | \ | 111 |SID:10/ \ / | | \ / \ / | | \ SID:80 | 112 | A1 / SID:100 / / SID:200 A8 | 113 | \ / \ | | / \ / \ | | / | 114 | \ / \ | | / \ / \ | | / | 115 | \ / \ | |/ \ / \| | / | 116 | A4-----A5------GW12------C2------GW22-------A7 | 117 | SID:40 SID:50 | | | | SID:70 | 118 +-----------------------+ +---------------+ +------------------+ 120 Figure 1 122 The figure above describes a network example with two groups of the 123 domain boundary nodes. The GW11 and GW12 are in the same anycast 124 group. They are all configured with the same anycast prefix and the 125 same prefix-sid 100, in addition, GW11 has node-sid 110 and GW12 has 126 node-sid 120. All these prefix-sid should be advertised to the 127 Neighbors(e.g, node A3 and A5), and the anycast-group forwarding 128 entry will be set up by the direct Neighbor node A3 and A5. For 129 example, the anycast-group forwarding entry created by A3 contains a 130 master item which points to anycast-sid 100 and a slave item which 131 points to node-sid 120. 133 When A3 detects GW11 failure, it immediately diverting traffic from 134 GW11 to A4 (e.g. the best next-hop to node-sid 120) according to the 135 anycast-group forwarding entry. 137 It is an implementation choice for data-plane whether the slave item 138 only points to node-sid 120 for cascade table lookup, or integrates 139 the forwarding information of node-sid 120 (such as a single next- 140 hop, a TI-LFA FRR index for cascade table lookup, or an ECMP index 141 for cascade table lookup). 143 Note that the anycast-group FRR described in this document could co- 144 exist with other FRR solutions, such as LFA/RLFA/TI-LFA. The 145 anycast-group FRR solution needn't complex alternate path 146 computation, it just reuses the forwarding information which points 147 to the slave boundary node. 149 5. Security Considerations 151 TBD. 153 6. Acknowledgements 155 TBD. 157 7. Normative references 159 [I-D.ietf-isis-segment-routing-extensions] 160 Previdi, S., Filsfils, C., Bashandy, A., Gredler, H., 161 Litkowski, S., Decraene, B., and J. Tantsura, "IS-IS 162 Extensions for Segment Routing", draft-ietf-isis-segment- 163 routing-extensions-13 (work in progress), June 2017. 165 [I-D.ietf-ospf-ospfv3-segment-routing-extensions] 166 Psenak, P., Previdi, S., Filsfils, C., Gredler, H., 167 Shakir, R., Henderickx, W., and J. Tantsura, "OSPFv3 168 Extensions for Segment Routing", draft-ietf-ospf-ospfv3- 169 segment-routing-extensions-10 (work in progress), 170 September 2017. 172 [I-D.ietf-ospf-segment-routing-extensions] 173 Psenak, P., Previdi, S., Filsfils, C., Gredler, H., 174 Shakir, R., Henderickx, W., and J. Tantsura, "OSPF 175 Extensions for Segment Routing", draft-ietf-ospf-segment- 176 routing-extensions-22 (work in progress), November 2017. 178 [I-D.ietf-spring-segment-routing] 179 Filsfils, C., Previdi, S., Ginsberg, L., Decraene, B., 180 Litkowski, S., and R. Shakir, "Segment Routing 181 Architecture", draft-ietf-spring-segment-routing-13 (work 182 in progress), October 2017. 184 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 185 Requirement Levels", BCP 14, RFC 2119, 186 DOI 10.17487/RFC2119, March 1997, 187 . 189 [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol 190 Label Switching Architecture", RFC 3031, 191 DOI 10.17487/RFC3031, January 2001, 192 . 194 Authors' Addresses 196 Ran Chen 197 ZTE Corporation 198 No.50 Software Avenue,Yuhuatai District 199 Nanjing, Jiangsu Province 210012 200 China 202 Phone: +86 025 88014636 203 Email: chen.ran@zte.com.cn 205 Shaofu Peng 206 ZTE Corporation 207 No.68 Zijinghua Road,Yuhuatai District 208 Nanjing, Jiangsu Province 210012 209 China 211 Email: peng.shaofu@zte.com.cn