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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (December 30, 2011) is 4500 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Outdated reference: A later version (-06) exists of draft-ietf-grow-va-04 == Outdated reference: A later version (-09) exists of draft-ietf-idr-reserved-extended-communities-01 Summary: 1 error (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group P. Francis 3 Internet-Draft MPI-SWS 4 Intended status: Informational X. Xu 5 Expires: July 2, 2012 Huawei 6 H. Ballani 7 Cornell U. 8 D. Jen 9 UCLA 10 R. Raszuk, Ed. 11 NTT MCL Inc. 12 L. Zhang 13 UCLA 14 December 30, 2011 16 Auto-Configuration in Virtual Aggregation 17 draft-ietf-grow-va-auto-05.txt 19 Abstract 21 Virtual Aggregation as specified in [I-D.ietf-grow-va] requires 22 configuration of a static "VP-List" on all routers. The VP-List 23 allows routers to know which prefixes may or may not be FIB- 24 installed. This draft specified an optional method of determining 25 this that requires far less configuration. Specifically, it requires 26 the configuration of a "VP-Range" in ASBRs connected to transit and 27 peer ISPs. A Non-transitive Extended Communities Attribute is used 28 to convey to other routers that a given route can be FIB-suppressed. 30 Status of this Memo 32 This Internet-Draft is submitted to IETF in full conformance with the 33 provisions of BCP 78 and BCP 79. 35 Internet-Drafts are working documents of the Internet Engineering 36 Task Force (IETF). Note that other groups may also distribute 37 working documents as Internet-Drafts. The list of current Internet- 38 Drafts is at http://datatracker.ietf.org/drafts/current/. 40 Internet-Drafts are draft documents valid for a maximum of six months 41 and may be updated, replaced, or obsoleted by other documents at any 42 time. It is inappropriate to use Internet-Drafts as reference 43 material or to cite them other than as "work in progress." 45 This Internet-Draft will expire on July 2, 2012. 47 Copyright Notice 48 Copyright (c) 2011 IETF Trust and the persons identified as the 49 document authors. All rights reserved. 51 This document is subject to BCP 78 and the IETF Trust's Legal 52 Provisions Relating to IETF Documents 53 (http://trustee.ietf.org/license-info) in effect on the date of 54 publication of this document. Please review these documents 55 carefully, as they describe your rights and restrictions with respect 56 to this document. Code Components extracted from this document must 57 include Simplified BSD License text as described in Section 4.e of 58 the Trust Legal Provisions and are provided without warranty as 59 described in the Simplified BSD License. 61 Table of Contents 63 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 64 1.1. Requirements notation . . . . . . . . . . . . . . . . . . . 3 65 2. Specification . . . . . . . . . . . . . . . . . . . . . . . . . 3 66 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 67 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 68 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 69 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 70 6.1. Normative References . . . . . . . . . . . . . . . . . . . 5 71 6.2. Informative References . . . . . . . . . . . . . . . . . . 5 72 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 74 1. Introduction 76 As the current VA specification stands ([I-D.ietf-grow-va]), routers 77 have to know which prefixes they must FIB-install and which they need 78 not FIB-install. The VP-List tells them this: they must FIB-install 79 routes to Virtual Prefixes (VP), and they need not FIB-install routes 80 to prefixes that fall within VPs for which they are not an 81 Aggregation Point Router (APR). The same VP-List must be installed 82 in every router. 84 This draft specifies an optional alternative to the VP-List that 85 requires far less configuration. Specifically, a list of one or more 86 "VP-Ranges" is configured in ASBRs --- typically ASBRs that do not 87 connect to customer networks. These ASBRs then simply tag routes as 88 to whether the route can be suppressed. This is simpler than the 89 current configured VP-List approach in two regards. First, fewer 90 routers need to be configured. Second, the VP-Range is simpler than 91 the VP-List. In most cases, once an ISP is past its initial VA roll- 92 out phase, the VP-Range consists of a single 0/0 entry. 94 This draft uses terms defined in [I-D.ietf-grow-va]. 96 1.1. Requirements notation 98 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 99 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 100 document are to be interpreted as described in [RFC2119]. 102 2. Specification 104 With the "VP-Range" approach to determining suppressability, certain 105 ASBRs are designated as "tagging routers". Tagging routers 106 explicitly tag routes with a Non-transitive Extended Communities 107 Attribute that indicates whether the route can be FIB-suppressed. 108 All ASBRs that connect to one or more transit provider ISPs MUST be 109 tagging routers. ASBRs that connect to one or more peer ISPs SHOULD 110 be tagging routers. ASBRs that connect to customer networks SHOULD 111 NOT be tagging routers. 113 Tagging routers are configured with a "VP-Range" list. This consists 114 of the ranges of IP address that are collectively covered by all VPs 115 in the AS. In a mature deployment of VA, the range would amount to 116 all IP addresses, in which case the VP-Range is simply 0/0. Early in 117 VA deployment, when an ISP is still in the testing or roll-out phase, 118 the VP-Range may consist of multiple entries. 120 Tagging routers SHOULD tag any route whose prefix falls within the 121 VP-Range with a "can-suppress" tag, with the following exceptions: 123 1. Tagging routers MUST NOT tag VP routes with can-suppress (where a 124 VP route is that route to the VP that the router originates in 125 its role as an APR). 126 2. If the ISP has a policy of FIB-installing customer routes, then 127 routes received from customers SHOULD NOT be tagged with can- 128 suppress. 130 The can-suppress tag itself is an Extended Communities Attribute 131 [RFC4360] to be assigned by IANA from the "well-known" pool define in 132 [I-D.ietf-idr-reserved-extended-communities]. The Transitive Bit 133 MUST be set to value 1 (the community is non-transitive across ASes). 135 Routers install or suppress FIB entries according to the following 136 rules. Note that tagging routers conceptually follow these rules 137 after tagging (or not tagging) the route. Note also that these rules 138 apply only to the route used by the router as the best route. In 139 other words, if a router receives two routes for the same prefix, and 140 one route is tagged can-suppress and the other is not, the router 141 follows these rules only with respect to the route that it selects as 142 the best route. 144 1. Routes without the can-suppress tag MUST be FIB-installed. 145 2. APRs MUST FIB-install routes for sub-prefixes that fall within 146 the APR's VPs, whether or not the route is tagged can-suppress. 147 3. Otherwise, routers MAY FIB-suppress routes tagged as can- 148 suppress. 150 3. IANA Considerations 152 IANA is requested to assign, from the registry "BGP Assigned non- 153 transitive extended communities", a value TBD for "VA can suppress": 155 Registry Name: BGP Assigned non-transitive extended 156 communities 158 Name Type Value 159 ---- ---------- 160 VA can suppress TBD 162 4. Security Considerations 164 As of this writing, there are no known new security threats 165 introduced by this draft. 167 5. Acknowledgements 169 The authors would like to thank Wes George and Bruno Decraene for 170 their reviews and suggestions. 172 6. References 174 6.1. Normative References 176 [I-D.ietf-grow-va] 177 Francis, P., Xu, X., Ballani, H., Jen, D., Raszuk, R., and 178 L. Zhang, "FIB Suppression with Virtual Aggregation", 179 draft-ietf-grow-va-04 (work in progress), Oct 2009. 181 [I-D.ietf-idr-reserved-extended-communities] 182 Decraene, B. and P. Francois, "Assigned BGP extended 183 communities", 184 draft-ietf-idr-reserved-extended-communities-01 (work in 185 progress), May 2011. 187 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 188 Requirement Levels", BCP 14, RFC 2119, March 1997. 190 [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended 191 Communities Attribute", RFC 4360, February 2006. 193 6.2. Informative References 195 Authors' Addresses 197 Paul Francis 198 Max Planck Institute for Software Systems 199 Gottlieb-Daimler-Strasse 200 Kaiserslautern 67633 201 Germany 203 Phone: +49 631 930 39600 204 Email: francis@mpi-sws.org 205 Xiaohu Xu 206 Huawei Technologies 207 No.3 Xinxi Rd., Shang-Di Information Industry Base, Hai-Dian District 208 Beijing, Beijing 100085 209 P.R.China 211 Phone: +86 10 82836073 212 Email: xuxh@huawei.com 214 Hitesh Ballani 215 Cornell University 216 4130 Upson Hall 217 Ithaca, NY 14853 218 US 220 Phone: +1 607 279 6780 221 Email: hitesh@cs.cornell.edu 223 Dan Jen 224 UCLA 225 4805 Boelter Hall 226 Los Angeles, CA 90095 227 US 229 Phone: 230 Email: jenster@cs.ucla.edu 232 Robert Raszuk (editor) 233 NTT MCL Inc. 234 101 S Ellsworth Avenue Suite 350 235 San Mateo, CA 94401 236 US 238 Email: robert@raszuk.net 240 Lixia Zhang 241 UCLA 242 3713 Boelter Hall 243 Los Angeles, CA 90095 244 US 246 Phone: 247 Email: lixia@cs.ucla.edu