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(See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (June 6, 2014) is 3584 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 (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 IDR K. Patel 3 Internet-Draft E. Chen 4 Updates: 2918 (if approved) Cisco Systems 5 Intended status: Standards Track B. Venkatachalapathy 6 Expires: December 8, 2014 7 June 6, 2014 9 Enhanced Route Refresh Capability for BGP-4 10 draft-ietf-idr-bgp-enhanced-route-refresh-08.txt 12 Abstract 14 In this document we enhance the existing BGP route refresh mechanisms 15 to provide for the demarcation of the beginning and the ending of a 16 route refresh. The enhancement can be used to facilitate correction 17 of BGP RIB inconsistencies in a non-disruptive manner. 19 Status of This Memo 21 This Internet-Draft is submitted in full conformance with the 22 provisions of BCP 78 and BCP 79. 24 Internet-Drafts are working documents of the Internet Engineering 25 Task Force (IETF). Note that other groups may also distribute 26 working documents as Internet-Drafts. The list of current Internet- 27 Drafts is at http://datatracker.ietf.org/drafts/current/. 29 Internet-Drafts are draft documents valid for a maximum of six months 30 and may be updated, replaced, or obsoleted by other documents at any 31 time. It is inappropriate to use Internet-Drafts as reference 32 material or to cite them other than as "work in progress." 34 This Internet-Draft will expire on December 8, 2014. 36 Copyright Notice 38 Copyright (c) 2014 IETF Trust and the persons identified as the 39 document authors. All rights reserved. 41 This document is subject to BCP 78 and the IETF Trust's Legal 42 Provisions Relating to IETF Documents 43 (http://trustee.ietf.org/license-info) in effect on the date of 44 publication of this document. Please review these documents 45 carefully, as they describe your rights and restrictions with respect 46 to this document. Code Components extracted from this document must 47 include Simplified BSD License text as described in Section 4.e of 48 the Trust Legal Provisions and are provided without warranty as 49 described in the Simplified BSD License. 51 Table of Contents 53 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 54 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2 55 3. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 2 56 3.1. Enhanced Route Refresh Capability . . . . . . . . . . . . 3 57 3.2. Subtypes for ROUTE-REFRESH Message . . . . . . . . . . . 3 58 4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 3 59 5. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 4 60 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 61 7. Security Considerations . . . . . . . . . . . . . . . . . . . 6 62 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 63 9. Normative References . . . . . . . . . . . . . . . . . . . . 6 64 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 66 1. Introduction 68 It is sometimes necessary to perform routing consistency validations 69 such as checking for possible missing withdraws between BGP speakers 70 [RFC4271]. Currently such validations typically involve off-line, 71 manual operations which can be tedious and time consuming. 73 In this document we enhance the existing BGP route refresh mechanisms 74 [RFC2918] to provide for the demarcation of the beginning and the 75 ending of a route refresh (which refers to the complete re- 76 advertisement of the Adj-RIB-Out to a peer, subject to routing 77 policies). The enhancement can be used to facilitate on-line, non- 78 disruptive consistency validation of BGP routing updates. 80 2. Requirements Language 82 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 83 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to 84 be interpreted as described in [RFC2119] only when they appear in all 85 upper case. They may also appear in lower or mixed case as English 86 words, without any normative meaning. 88 3. Protocol Extensions 90 The BGP protocol extensions introduced in this document include the 91 definition of a new BGP capability, named "Enhanced Route Refresh 92 Capability", and the specification of the message subtypes for the 93 ROUTE-REFRESH message. 95 3.1. Enhanced Route Refresh Capability 97 The "Enhanced Route Refresh Capability" is a new BGP capability 98 [RFC5492]. IANA has assigned a Capability Code of 70 for this 99 capability . The Capability Length field of this capability is zero. 101 By advertising this capability to a peer, a BGP speaker conveys to 102 the peer that the speaker supports the message subtypes for the 103 ROUTE-REFRESH message and the related procedures described in this 104 document. 106 3.2. Subtypes for ROUTE-REFRESH Message 108 The "Reserved" field of the ROUTE-REFRESH message specified in 109 [RFC2918] is re-defined as the "Message Subtype" with the following 110 values: 112 0 - Normal route refresh request [RFC2918] 113 with/without ORF [RFC5291] 114 1 - Demarcation of the beginning of a route refresh operation. 115 Also known as a "BoRR message" or just a "BoRR". 116 2 - Demarcation of the ending of a route refresh operation. 117 Also known as a "EoRR message" or just a "EoRR". 119 The remaining values of the message subtypes are reserved for future 120 use. The use of the new message subtypes is described in the 121 Operations section. 123 4. Operation 125 A BGP speaker that supports the message subtypes for the ROUTE- 126 REFRESH message and the related procedures SHOULD advertise the 127 "Enhanced Route Refresh Capability". 129 The following procedures are applicable only if a BGP speaker has 130 received the "Enhanced Route Refresh Capability" from a peer. 132 Before the speaker starts a route refresh that is either initiated 133 locally, or in response to a "normal route refresh request" from the 134 peer, the speaker MUST send a BoRR message. After the speaker 135 completes the re-advertisement of the entire Adj-RIB-Out to the peer, 136 it MUST send an EoRR message. 138 Conceptually the "entire Adj-RIB-Out" for a peer in this section 139 refers to all the route entries in the "Adj-RIB-Out" for the peer at 140 the start of the route refresh operation. These route entries 141 comprise both the reachability as well as unreachability information. 143 When a route entry in the "Adj-RIB-Out" changes, only the modified 144 route entry needs to be advertised. 146 In processing a ROUTE-REFRESH message from a peer, the BGP speaker 147 MUST examine the "message subtype" field of the message and take the 148 appropriate actions. The message processing rules for ROUTE-REFRESH 149 message with subtype of 0 are described in [RFC2918] and [RFC5291]. 150 A BGP speaker can receive a BoRR message from a peer at any time, 151 either as a result of a peer responding to a ROUTE-REFESH message, or 152 as a result of a peer unilaterally initiating a route refresh. When 153 a BGP speaker receives a BoRR message from a peer, it MUST mark all 154 the routes with the given from that peer as stale. As it 155 receives routes from its peer's subsequent Adj-RIB-Out re- 156 advertisement, these replace any corresponding stale routes. When a 157 BGP speaker receives an EoRR message from a peer, it MUST immediately 158 remove any routes from the peer that are still marked as stale for 159 that . Such purged routes MAY be logged for future 160 analysis. A BGP speaker MAY ignore any EoRR message received without 161 a prior receipt of an associated BoRR message. Such messages MAY be 162 logged for future analysis. 164 An implementation MAY impose a locally configurable upper bound on 165 how long it would retain any stale routes. Once the upper bound is 166 reached, the implementation MAY remove any routes from the peer that 167 are still marked as stale for that without waiting for an 168 EoRR message. 170 The following procedures are specified in order to simplify the 171 interaction with the BGP Graceful Restart [RFC4724]. In particular, 172 these procedures ensure that End-of-RIB (EoR) defined in Graceful 173 Restart and EoRR as defined in this specification are kept separate, 174 thereby avoiding any premature cleanup of stale routes. For a BGP 175 speaker that supports the BGP Graceful Restart, it MUST NOT send a 176 BoRR for an AFI/SAFI to a neighbor before it sends the EoR for the 177 AFI/SAFI to the neighbor. A BGP speaker that has received the 178 Graceful Restart Capability from its neighbor, MUST ignore any BoRRs 179 for an AFI/SAFI from the neighbor before the speaker receives the EoR 180 for the given AFI/SAFI from the neighbor. The BGP speaker SHOULD log 181 an error of the condition for further analysis. 183 5. Error Handling 185 This document defines a new NOTIFICATION error code: 187 Error Code Symbolic Name 189 TBD ROUTE-REFRESH Message Error 191 The following error subcodes are defined as well: 193 Subcode Symbolic Name 195 1 Invalid Message Length 197 The error handling specified in this section is applicable only when 198 a BGP speaker has received the "Enhanced Route Refresh Capability" 199 from a peer. 201 If the length, excluding the fixed-size message header, of the 202 received ROUTE-REFRESH message with Message Subtype 1 and 2 is not 4, 203 then the BGP speaker MUST send a NOTIFICATION message with the Error 204 Code of "ROUTE-REFRESH Message Error" and the subcode of "Invalid 205 Message Length". The Data field of the NOTIFICATION message MUST 206 contain the complete ROUTE-REFRESH message. 208 When the BGP speaker receives a ROUTE-REFRESH message with a "Message 209 Subtype" field other than 0, 1 or 2, it MUST ignore the received 210 ROUTE-REFRESH message. It SHOULD log an error for further analysis. 212 6. IANA Considerations 214 This document defines the Enhanced Route Refresh Capability for BGP. 215 The Capability Code 70 has been assigned by the IANA. This document 216 also defines two new subcodes for the Route Refresh message. They 217 need to be registered with the IANA. We request IANA to create a new 218 registry for the Route Refresh message subcodes as follows: 220 Under "Border Gateway Protocol (BGP) Parameters": 221 Registry: "BGP Route Refresh Subcodes" 222 Reference: [draft-ietf-idr-bgp-enhanced-refresh-06.txt] 223 Registration Procedure(s): Values 0-127 Standards Action, values 224 128-254 First Come, First Served, Value 255 reserved 226 Value Code Reference 227 0 Route-Refresh [RFC2918], [RFC5291] 228 1 BoRR [draft-ietf-idr-bgp-enhanced-refresh-06.txt] 229 2 EoRR [draft-ietf-idr-bgp-enhanced-refresh-06.txt] 230 3-255 Reserved 232 In addition, this document defines an NOTIFICATION error code and 233 several error subcodes for the ROUTE-REFRESH message. The 234 NOTIFICATION error code needs to be registered with the IANA. We 235 request IANA to create a new registry for the error subcodes as 236 follows: 238 Under "BGP Error Subcodes": 239 Registry: "BGP ROUTE-REFRESH Message Error subcodes" 240 Reference: [draft-ietf-idr-bgp-enhanced-refresh-06.txt] 241 Registration Procedure(s): Values 0-127 Standards Action, values 242 128-255 First Come, First Served 244 Value Code Reference 245 0 Reserved 246 1 Invalid Message Length [draft-ietf-idr-bgp-enhanced-refresh-06.txt] 248 7. Security Considerations 250 This extension to BGP does not change the underlying security issues. 252 8. Acknowledgements 254 The authors would like to thank Pedro Marques, Pradosh Mohapatra, 255 Robert Raszuk, Pranav Mehta, Shyam Sethuram, Bruno Decraene, Martin 256 Djernaes, Jeff Haas, Ilya Varlashkin, Rob Shakir, Paul Jakma, Jie 257 Dong, Qing Zeng, Albert Tian, Jakob Heitz and Chris Hall for their 258 review and comments. The authors would like to thank John Scudder 259 for the review and contribution to this document. 261 9. Normative References 263 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 264 Requirement Levels", BCP 14, RFC 2119, March 1997. 266 [RFC2918] Chen, E., "Route Refresh Capability for BGP-4", RFC 2918, 267 September 2000. 269 [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway 270 Protocol 4 (BGP-4)", RFC 4271, January 2006. 272 [RFC4724] Sangli, S., Chen, E., Fernando, R., Scudder, J., and Y. 273 Rekhter, "Graceful Restart Mechanism for BGP", RFC 4724, 274 January 2007. 276 [RFC5291] Chen, E. and Y. Rekhter, "Outbound Route Filtering 277 Capability for BGP-4", RFC 5291, August 2008. 279 [RFC5492] Scudder, J. and R. Chandra, "Capabilities Advertisement 280 with BGP-4", RFC 5492, February 2009. 282 Authors' Addresses 284 Keyur Patel 285 Cisco Systems 286 170 W. Tasman Drive 287 San Jose, CA 95134 288 USA 290 Email: keyupate@cisco.com 292 Enke Chen 293 Cisco Systems 294 170 W. Tasman Drive 295 San Jose, CA 95134 296 USA 298 Email: enkechen@cisco.com 300 Balaji Venkatachalapathy 302 Email: balaji_pv@hotmail.com