idnits 2.17.1 draft-ymbk-idr-bgp-eotr-policy-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 : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document seems to lack the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords -- however, there's a paragraph with a matching beginning. Boilerplate error? (The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). -- The document date (March 13, 2017) is 2594 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-03) exists of draft-ymbk-idr-bgp-open-policy-02 == Outdated reference: A later version (-11) exists of draft-ietf-idr-route-leak-detection-mitigation-03 == Outdated reference: A later version (-23) exists of draft-ietf-sidr-bgpsec-protocol-15 Summary: 0 errors (**), 0 flaws (~~), 5 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Azimov 3 Internet-Draft E. Bogomazov 4 Intended status: Standards Track Qrator Labs 5 Expires: September 14, 2017 R. Bush 6 Internet Initiative Japan 7 K. Patel 8 Arrcus, Inc. 9 March 13, 2017 11 Route Leak Detection and Filtering using Roles in Update and Open 12 messages 13 draft-ymbk-idr-bgp-eotr-policy-00 15 Abstract 17 [draft-ymbk-idr-bgp-open-policy] defines a BGP OPEN capability and 18 consequent route marking which enforces a valley-free peering 19 relationship. This document defines an eOTC (external Only To 20 Customer) transitive BGP attribute which propagates the specific 21 marking to automatically detect route leaks. The goal is to allow a 22 distant AS to determine a violation of valley-free peering. 24 Requirements Language 26 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 27 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to 28 be interpreted as described in RFC 2119 [RFC2119] only when they 29 appear in all upper case. They may also appear in lower or mixed 30 case as English words, without normative meaning. 32 Status of This Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at http://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on September 14, 2017. 49 Copyright Notice 51 Copyright (c) 2017 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (http://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 67 2. BGP External Only To Customer attribute . . . . . . . . . . . 3 68 3. Compatibility with BGPsec . . . . . . . . . . . . . . . . . . 4 69 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 70 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 71 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 72 6.1. Normative References . . . . . . . . . . . . . . . . . . 5 73 6.2. Informative References . . . . . . . . . . . . . . . . . 5 74 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 76 1. Introduction 78 For the purpose of this document, BGP route leaks are when a BGP 79 route was learned from transit provider or peer is announced to 80 another provider or peer. See 81 [I-D.ietf-grow-route-leak-problem-definition]. These are usually the 82 result of misconfigured or absent BGP route filtering or lack of 83 coordination between two BGP speakers. 85 [I-D.ietf-idr-route-leak-detection-mitigation] describes a method of 86 marking and detecting leaks which relies on operator maintained 87 markings. Unfortunately, in most cases, a leaking router will likely 88 also be misconfigured to mark incorrectly. 90 It has been suggested to use white list filtering, relying on knowing 91 the prefixes in the peer's customer cone as import filtering, in 92 order to detect route leaks. Unfortunately, a large number of medium 93 transit operators use a single prefix list as only the ACL for export 94 filtering, without community tagging and without paying attention to 95 the source of a learned route. So, if they learn a customer's route 96 from their provider or peer - they will announce it in all 97 directions, including other providers or peers. This 98 misconfiguration affects a limited number of prefixes; but such route 99 leaks will obviously bypass customer cone import filtering made by 100 upper level upstream providers. 102 This document specifies a way to to create automatic filters for 103 detection of route leaks via new BGP Path Attribute which is set 104 according to BGP Roles ([I-D.ymbk-idr-bgp-open-policy]) . While iOTC 105 provides strong vendor-code-based enforcement of route leak 106 prevention, route leaks could still exist as result of misconfigured 107 old BGP implementations. Route leaks could also be result of 108 malicious activity such as MITM attacks or DoS. The goal of this 109 proposal is to allow a distant AS to determine a violation of valley- 110 free peering that is made by mistake or by purpose. 112 2. BGP External Only To Customer attribute 114 The External Only To Customer (eOTC) attribute is a new optional, 115 transitive BGP Path attribute with the Type Code . This 116 attribute is four bytes and contains an AS number of the AS that 117 added the attribute to the route. 119 There are four rules for setting the eOTC attribute: 121 1. If eOTC is not set and the sender's Role is Provider or Peer, the 122 eOTC attribute MUST be added with value equal to the sender's AS 123 number. 125 2. If eOTC is not set and the sender's Role is Complex and the 126 prefix role is Provider or Peer, the eOTC attribute MUST be added 127 with value equal to to the sender's AS number. 129 3. If eOTC is set, the receiver's Role is Provider or Peer, and its 130 value is not the neighbor's AS number then the incoming route is 131 route leak and MUST be given a lower local preference, or MAY be 132 dropped. 134 4. If eOTC is set, the receiver's Role is Complex, the prefix role 135 Role is Provider or Peer, and the eOTC value is not equal to the 136 neighbor's AS number, then the incoming route is a route leak and 137 MUST be given a lower local preference, or they MAY be dropped. 139 These four rules provide mechanism for route leak detection that is 140 created by a distant party in the AS_Path. 142 3. Compatibility with BGPsec 144 For BGPsec [I-D.ietf-sidr-bgpsec-protocol] enabled routers, the Flags 145 field will have a bit added to indicate that an eOTC attribute 146 exists. The eOTC value will be automatically carried in AS field of 147 the added Secure_Path Segment. 149 When a route is translated from a BGPsec enabled router to a non- 150 BGPsec router, in addition to AS_PATH reconstruction, reconstruction 151 MUST be performed for the eOTC attribute. If Flag bit was set in one 152 of Secure_Path Segments, the eOTC attribute SHOULD be added with the 153 AS number of the segment in which it appears for the first time. 155 4. IANA Considerations 157 This document defines a new optional, transitive BGP Path Attributes 158 option, named "External Only To Customer", assigned value [To 159 be removed upon publication: http://www.iana.org/assignments/bgp- 160 parameters/bgp-parameters.xhtml#bgp-parameters-2] [RFC4271]. The 161 length of this attribute is 4. 163 5. Security Considerations 165 This document proposes a mechanism for detection of route leaks that 166 are the result of BGP policy misconfiguration. If BGPSec is enabled 167 it will also provide mechanism to detect leaks that are result of 168 malicious activity. 170 Deliberate mis-marking of the eOTC flag could be used to affect the 171 BGP decision process, but could not sabotage a route's propagation. 173 eOTC is a transitive BGP AS_PATH attribute which reveals a 174 information about a BGP speaker's peering relationship. It will give 175 a strong hint that some link isn't customer to provider, but will not 176 help to distinguish if it is provider to customer or peer to peer. 177 In addition it could reveal sequence of p2c to downstream ISPs. If 178 eOTC is BGPsec signed, it can not be removed for peering 179 confidentiality. 181 Still, any Tier-1 number in AS_PATH could be used in the same way to 182 reveal possible p2c sequence. 184 6. References 185 6.1. Normative References 187 [I-D.ymbk-idr-bgp-open-policy] 188 Azimov, A., Bogomazov, E., Bush, R., Patel, K., and K. 189 Sriram, "Route Leak Detection and Filtering using Roles in 190 Update and Open messages", draft-ymbk-idr-bgp-open- 191 policy-02 (work in progress), November 2016. 193 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 194 Requirement Levels", BCP 14, RFC 2119, 195 DOI 10.17487/RFC2119, March 1997, 196 . 198 [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A 199 Border Gateway Protocol 4 (BGP-4)", RFC 4271, 200 DOI 10.17487/RFC4271, January 2006, 201 . 203 6.2. Informative References 205 [I-D.ietf-grow-route-leak-problem-definition] 206 Sriram, K., Montgomery, D., McPherson, D., Osterweil, E., 207 and B. Dickson, "Problem Definition and Classification of 208 BGP Route Leaks", draft-ietf-grow-route-leak-problem- 209 definition-06 (work in progress), May 2016. 211 [I-D.ietf-idr-route-leak-detection-mitigation] 212 Sriram, K., Montgomery, D., Dickson, B., Patel, K., and A. 213 Robachevsky, "Methods for Detection and Mitigation of BGP 214 Route Leaks", draft-ietf-idr-route-leak-detection- 215 mitigation-03 (work in progress), May 2016. 217 [I-D.ietf-sidr-bgpsec-protocol] 218 Lepinski, M. and K. Sriram, "BGPsec Protocol 219 Specification", draft-ietf-sidr-bgpsec-protocol-15 (work 220 in progress), March 2016. 222 Authors' Addresses 224 Alexander Azimov 225 Qrator Labs 227 Email: aa@qrator.net 228 Eugene Bogomazov 229 Qrator Labs 231 Email: eb@qrator.net 233 Randy Bush 234 Internet Initiative Japan 236 Email: randy@psg.com 238 Keyur Patel 239 Arrcus, Inc. 241 Email: keyur@arrcus.com