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If it is intended as a requirements expression, it should be rewritten using one of the combinations defined in RFC 2119; otherwise it should not be all-uppercase. == The expression 'MAY NOT', while looking like RFC 2119 requirements text, is not defined in RFC 2119, and should not be used. Consider using 'MUST NOT' instead (if that is what you mean). Found 'MAY NOT' in this paragraph: When using a metric which is also influenced by other local policy, the operator should be careful not to create privilege upgrade vulnerabilities. E.g. if Local Pref is set depending on validity state, be careful that peer community signaling MAY NOT upgrade an invalid announcement to valid or better. -- The document date (May 10, 2011) is 4735 days in the past. Is this intentional? Checking references for intended status: Best Current Practice ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-13) exists of draft-ietf-sidr-arch-12 ** Downref: Normative reference to an Informational draft: draft-ietf-sidr-arch (ref. 'I-D.ietf-sidr-arch') == Outdated reference: A later version (-09) exists of draft-ietf-sidr-repos-struct-07 == Outdated reference: A later version (-12) exists of draft-ietf-sidr-roa-format-10 == Outdated reference: A later version (-26) exists of draft-ietf-sidr-rpki-rtr-11 == Outdated reference: A later version (-10) exists of draft-ietf-sidr-pfx-validate-01 == Outdated reference: A later version (-16) exists of draft-ietf-sidr-ghostbusters-03 == Outdated reference: A later version (-08) exists of draft-ietf-sidr-ltamgmt-00 Summary: 1 error (**), 0 flaws (~~), 9 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group R. Bush 3 Internet-Draft Internet Initiative Japan 4 Intended status: BCP May 10, 2011 5 Expires: November 11, 2011 7 RPKI-Based Origin Validation Operation 8 draft-ietf-sidr-origin-ops-08 10 Abstract 12 Deployment of RPKI-based BGP origin validation has many operational 13 considerations. This document attempts to collect and present them. 14 It is expected to evolve as RPKI-based origin validation is deployed 15 and the dynamics are better understood. 17 Requirements Language 19 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 20 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 21 document are to be interpreted as described in RFC 2119 [RFC2119]. 23 Status of this Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at http://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on November 11, 2011. 40 Copyright Notice 42 Copyright (c) 2011 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (http://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2. Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . 3 59 3. RPKI Distribution and Maintenance . . . . . . . . . . . . . . . 3 60 4. Within a Network . . . . . . . . . . . . . . . . . . . . . . . 5 61 5. Routing Policy . . . . . . . . . . . . . . . . . . . . . . . . 5 62 6. Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 63 7. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 64 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 65 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 7 66 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 67 10.1. Normative References . . . . . . . . . . . . . . . . . . . 7 68 10.2. Informative References . . . . . . . . . . . . . . . . . . 8 69 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 8 71 1. Introduction 73 RPKI-based origin validation relies on widespread propagation of the 74 Resource Public Key Infrastructure (RPKI) [I-D.ietf-sidr-arch]. How 75 the RPKI is distributed and maintained globally is a serious concern 76 from many aspects. 78 The global RPKI is in very initial stages of deployment, there is no 79 root trust anchor, initial testing is being done by the IANA and some 80 RIRs, and there is a technical testbed. It is thought that origin 81 validation based on the RPKI will be deployed incrementally over the 82 next year to five years. 84 Origin validation only need be done by an AS's border routers and is 85 designed so that it can be used to protect announcements which are 86 originated by large providers, upstreams and downstreams, and by 87 small stub/enterprise/edge routers. 89 Origin validation has been designed to be deployed on current routers 90 without significant hardware upgrade. It should be used by everyone 91 from large backbones to small stub/entetprise/edge routers. 93 RPKI-based origin validation has been designed so that, with prudent 94 local routing policies, there is little risk that what is seen as 95 today's normal Internet routing is threatened by imprudent deployment 96 of the global RPKI, see Section 5. 98 2. Suggested Reading 100 It is assumed that the reader understands BGP, [RFC4271], the RPKI, 101 see [I-D.ietf-sidr-arch], the RPKI Repository Structure, see 102 [I-D.ietf-sidr-repos-struct], ROAs, see [I-D.ietf-sidr-roa-format], 103 the RPKI to Router Protocol, see [I-D.ietf-sidr-rpki-rtr], RPKI-based 104 Prefix Validation, see [I-D.ietf-sidr-pfx-validate], and Ghostbuster 105 Records, see [I-D.ietf-sidr-ghostbusters]. 107 3. RPKI Distribution and Maintenance 109 The RPKI is a distributed database containing certificates, CRLs, 110 manifests, ROAs, and Ghostbuster Records as described in 111 [I-D.ietf-sidr-repos-struct]. Policies and considerations for RPKI 112 object generation and maintenance are discussed elsewhere. 114 A local valid cache containing all RPKI data may be gathered from the 115 global distributed database using the rsync protocol and a validation 116 tool such as rcynic. 118 Validated caches may also be created and maintained from other 119 validated caches. Network operators SHOULD take maximum advantage of 120 this feature to minimize load on the global distributed RPKI 121 database. 123 As RPKI-based origin validation relies on the availability of RPKI 124 data, operators SHOULD locate caches close to routers that require 125 these data and services. A router can peer with one or more nearby 126 caches. 128 For redundancy, a router SHOULD peer with more than one cache at the 129 same time. Peering with two or more, at least one local and others 130 remote, is recommended. 132 If an operator trusts upstreams to carry their traffic, they SHOULD 133 also trust the RPKI data those upstreams cache, and SHOULD peer with 134 those caches. Note that this places an obligation on those upstreams 135 to maintain fresh and reliable caches. 137 A transit provider or a network with peers SHOULD validate origins in 138 announcements made by upstreams, downstreams, and peers. They still 139 SHOULD trust the caches provided by their upstreams. 141 Before issuing a ROA for a block, an operator MUST ensure that any 142 sub-allocations from that block which are announced by other ASs, 143 e.g. customers, have correct ROAs in play. Otherwise, issuing a ROA 144 for the super-block will cause the announcements of sub-allocations 145 with no ROAs to be Invalid. 147 Use of RPKI-based origin validation obviates the utility of 148 announcing many longer prefix when the covering prefix would do. 150 To aid translation of ROAs into efficient search algorithms in 151 routers, ROAs SHOULD be as precise as possible, i.e. match prefixes 152 as announced in BGP. E.g. software and operators SHOULD avoid use of 153 excessive max length values in ROAs unless operationally necessary. 155 Therefore, ROA generation software MUST use the prefix length as the 156 max length if the user does not specify a max length. 158 Operators SHOULD be conservative in use of max length in ROAs. E.g., 159 if a prefix will have only a few sub-prefixes announced, multiple 160 ROAs for the specific announcements SHOULD be used as opposed to one 161 ROA with a long max length. 163 An environment where private address space is announced in eBGP the 164 operator MAY have private RPKI objects which cover these private 165 spaces. This will require a trust anchor created and owned by that 166 environment, see [I-D.ietf-sidr-ltamgmt]. 168 Operators issuing ROAs may have customers announce their own prefixes 169 and ASs into global eBGP but who do not wish to go though the work to 170 manage the relevant certificates and ROAs. The operator SHOULD 171 provision the RPKI data for these customers just as they provision 172 many other things for them. 174 While a an operator using RPKI data MAY choose any frequency they 175 wish for ensuring they have a fresh RPKI cache, if they use RPKI data 176 as an input to operational routing decisions, they SHOULD ensure 177 local cache freshness at least every four to six hours. 179 4. Within a Network 181 Origin validation need only be done by edge routers in a network, 182 those which border other networks/ASs. 184 A validating router will use the result of origin validation to 185 influence local policy within its network, see Section 5. In 186 deployment this policy should fit into the AS's existing policy, 187 preferences, etc. This allows a network to incrementally deploy 188 validation capable border routers. 190 eBGP speakers which face more critical peers or up/downstreams would 191 be candidates for the earliest deployment. Validating more critical 192 received announcements should be considered in partial deployment. 194 5. Routing Policy 196 Origin validation based on the RPKI merely marks a received 197 announcement as having an origin which is Valid, NotFound, or 198 Invalid. See [I-D.ietf-sidr-pfx-validate]. How this is used in 199 routing SHOULD be specified by the operator's local policy. 201 Local policy using relative preference is suggested to manage the 202 uncertainty associated with a system in early deployment, applying 203 local policy to eliminate the threat of unroutability of prefixes due 204 to ill-advised certification policies and/or incorrect certification 205 data. E.g. until the community feels comfortable relying on RPKI 206 data, routing on Invalid origin validity, though at a low preference, 207 MAY occur. 209 As origin validation will be rolled out incrementally, coverage will 210 be incomplete for a long time. Therefore, routing on NotFound 211 validity state SHOULD be done for a long time. As the transition 212 moves forward, the number of BGP announcements with validation state 213 NotFound should decrease. Hence an operator's policy SHOULD NOT be 214 overly strict, preferring Valid announcements, attaching a lower 215 preference to, but still using, NotFound announcements, and dropping 216 or giving very low preference to Invalid announcements. 218 Some may choose to use the large Local-Preference hammer. Others 219 might choose to let AS-Path rule and set their internal metric, which 220 comes after AS-Path in the BGP decision process. 222 When using a metric which is also influenced by other local policy, 223 the operator should be careful not to create privilege upgrade 224 vulnerabilities. E.g. if Local Pref is set depending on validity 225 state, be careful that peer community signaling MAY NOT upgrade an 226 invalid announcement to valid or better. 228 Announcements with Valid origins SHOULD be preferred over those with 229 NotFound or Invalid origins, if the latter are accepted at all. 231 Announcements with NotFound origins SHOULD be preferred over those 232 with Invalid origins. 234 Announcements with Invalid origins MAY be used, but SHOULD be less 235 preferred than those with Valid or NotFound. 237 6. Notes 239 Like the DNS, the global RPKI presents only a loosely consistent 240 view, depending on timing, updating, fetching, etc. Thus, one cache 241 or router may have different data about a particular prefix than 242 another cache or router. There is no 'fix' for this, it is the 243 nature of distributed data with distributed caches. 245 There is some uncertainty about the origin AS of aggregates and what, 246 if any, ROA can be used. The long range solution to this is the 247 deprecation of AS-SETs, see [I-D.wkumari-deprecate-as-sets]. 249 Operators which manage certificates SHOULD have RPKI Ghostbuster 250 Records (see [I-D.ietf-sidr-ghostbusters]), signed indirectly by End 251 Entity certificates, for those certificates on which others' routing 252 depends for certificate and/or ROA validation. 254 7. Security Considerations 256 As the BGP origin is not signed, origin validation is open to 257 malicious spoofing. It is only designed to deal with inadvertent 258 mis-advertisement. 260 Origin validation does not address the problem of AS-Path validation. 261 Therefore paths are open to manipulation, either malicious or 262 accidental. 264 The data plane may not follow the control plane. 266 Be aware of the class of privilege escalation issues discussed in 267 Section 5 above. 269 8. IANA Considerations 271 This document has no IANA Considerations. 273 9. Acknowledgments 275 The author wishes to thank Rob Austein, Steve Bellovin, Pradosh 276 Mohapatra, Chris Morrow, Sandy Murphy, Keyur Patel, Heather and Jason 277 Schiller, John Scudder, Maureen Stillman, and Dave Ward. 279 10. References 281 10.1. Normative References 283 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 284 Requirement Levels", BCP 14, RFC 2119, March 1997. 286 [I-D.ietf-sidr-arch] 287 Lepinski, M. and S. Kent, "An Infrastructure to Support 288 Secure Internet Routing", draft-ietf-sidr-arch-12 (work in 289 progress), February 2011. 291 [I-D.ietf-sidr-repos-struct] 292 Huston, G., Loomans, R., and G. Michaelson, "A Profile for 293 Resource Certificate Repository Structure", 294 draft-ietf-sidr-repos-struct-07 (work in progress), 295 February 2011. 297 [I-D.ietf-sidr-roa-format] 298 Lepinski, M., Kent, S., and D. Kong, "A Profile for Route 299 Origin Authorizations (ROAs)", 300 draft-ietf-sidr-roa-format-10 (work in progress), 301 February 2011. 303 [I-D.ietf-sidr-rpki-rtr] 304 Bush, R. and R. Austein, "The RPKI/Router Protocol", 305 draft-ietf-sidr-rpki-rtr-11 (work in progress), 306 March 2011. 308 [I-D.ietf-sidr-pfx-validate] 309 Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R. 310 Austein, "BGP Prefix Origin Validation", 311 draft-ietf-sidr-pfx-validate-01 (work in progress), 312 February 2011. 314 [I-D.ietf-sidr-ghostbusters] 315 Bush, R., "The RPKI Ghostbusters Record", 316 draft-ietf-sidr-ghostbusters-03 (work in progress), 317 March 2011. 319 [I-D.ietf-sidr-ltamgmt] 320 Kent, S. and M. Reynolds, "Local Trust Anchor Management 321 for the Resource Public Key Infrastructure", 322 draft-ietf-sidr-ltamgmt-00 (work in progress), 323 November 2010. 325 10.2. Informative References 327 [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway 328 Protocol 4 (BGP-4)", RFC 4271, January 2006. 330 [I-D.wkumari-deprecate-as-sets] 331 Kumari, W., "Deprecation of BGP AS_SET, AS_CONFED_SET.", 332 draft-wkumari-deprecate-as-sets-01 (work in progress), 333 September 2010. 335 Author's Address 337 Randy Bush 338 Internet Initiative Japan 339 5147 Crystal Springs 340 Bainbridge Island, Washington 98110 341 US 343 Phone: +1 206 780 0431 x1 344 Email: randy@psg.com