idnits 2.17.1 draft-ymbk-idr-isp-border-01.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 a Security Considerations section. 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 (May 15, 2017) is 2530 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) No issues found here. Summary: 1 error (**), 0 flaws (~~), 2 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: November 16, 2017 R. Bush 6 Internet Initiative Japan 7 K. Patel 8 Arrcus, Inc. 9 K. Sriram 10 US NIST 11 May 15, 2017 13 New definition of ISP internal eBGP border using BGP Roles 14 draft-ymbk-idr-isp-border-01 16 Abstract 18 This document proposes a new definition of ISP borders using BGP 19 Roles. It may be used to improve the BGP best path selection 20 algorithm for better support of hot-potato routing between different 21 internal ASNs of an ISP. It may also be used to enable transmission 22 of local attributes between different internal ASNs of an ISP. 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 November 16, 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. Changes in BGP decision process . . . . . . . . . . . . . . . 3 68 3. Local Attributes Transmission . . . . . . . . . . . . . . . . 3 69 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 70 5. Normative References . . . . . . . . . . . . . . . . . . . . 3 71 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 73 1. Introduction 75 The BGP best path selection algorithm (Section 9.1.2.2 of [RFC4271]) 76 has a very clear definition of a network border: different ASNs - 77 different networks. It differs from some real world situations when 78 two networks become one business entity and want to operate as one 79 network. 81 Today BGP does not provide any robust or automated support for such 82 merging networks: 84 o There is no support for carrying local attributes through this 85 border, 87 o Hot-potato routing, implemented by eBGP being preferred to iBGP, 88 does not work, and 90 o Route Leak prevention inside such a united network can not be 91 easily automated. 93 In [I-D.ymbk-idr-bgp-open-policy] BGP Roles were introduced - a 94 configuration option that strongly enforces agreement on real-world 95 peering relations between two BGP speakers. This configuration 96 option can accept values of: Peering, Customer, Provider and 97 Internal. These values could be used in a new ISP border definition: 98 Internal vs. External. With this definition of network borders, it 99 becomes easy to allow robust propagation of local attributes between 100 different ASNs of one ISP. It could be also used to improve the hot- 101 potato routing mechanism: where routes learned from External BGP 102 connections should be preferred over Internal, even those which cross 103 the ISP's internal AS/AS boundary. 105 2. Changes in BGP decision process 107 To improve hot-potato routing for networks with multiple ASNs we 108 propose to insert before d) in Section 9.1.2.2 of [RFC4271] next 109 step: 111 If at least one of the candidate routes was received via a BGP 112 session with External (Peer, Provider, Customer) role, remove from 113 consideration all routes that were received via BGP sessions with an 114 Internal role. 116 While this step will improve traffic control for ISPs with multiple 117 ASNs it will have no affect on ISPs with single ASN. 119 3. Local Attributes Transmission 121 Propagation of local attributes through an ISP's internal AS/AS 122 border could be enabled only if both sides set Internal roles in 123 their BGP Open negotiation. Different attributes may still have 124 different transmission policy: 126 o iOTC attribute from [I-D.ymbk-idr-bgp-open-policy] MUST be sent to 127 enforce route leak prevention, 129 o LOCAL_PREF attribute MAY be sent, and 131 o MED attribute MAY be sent without changes. 133 4. IANA Considerations 135 This document has no IANA actions. 137 5. Normative References 139 [I-D.ymbk-idr-bgp-open-policy] 140 Azimov, A., Bogomazov, E., Bush, R., Patel, K., and K. 141 Sriram, "Route Leak Prevention using Roles in Update and 142 Open messages", draft-ymbk-idr-bgp-open-policy-03 (work in 143 progress), March 2017. 145 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 146 Requirement Levels", BCP 14, RFC 2119, 147 DOI 10.17487/RFC2119, March 1997, 148 . 150 [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A 151 Border Gateway Protocol 4 (BGP-4)", RFC 4271, 152 DOI 10.17487/RFC4271, January 2006, 153 . 155 Authors' Addresses 157 Alexander Azimov 158 Qrator Labs 160 Email: aa@qrator.net 162 Eugene Bogomazov 163 Qrator Labs 165 Email: eb@qrator.net 167 Randy Bush 168 Internet Initiative Japan 170 Email: randy@psg.com 172 Keyur Patel 173 Arrcus, Inc. 175 Email: keyur@arrcus.com 177 Kotikalapudi Sriram 178 US NIST 180 Email: ksriram@nist.gov