Network Working Group J. Damas Internet-Draft Expires: June 18, 2003 F. Parent Viagenie A. Robachevski RIPE NCC December 18, 2002 RPSLng draft-damas-rpslng-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on June 18, 2003. Copyright Notice Copyright (C) The Internet Society (2002). All Rights Reserved. Abstract This memo presents a new set of simple extensions to the RPSL language enabling the language to document routing policies for the IPv6 and multicast address families currently used in the Internet. Damas, et al. Expires June 18, 2003 [Page 1] Internet-Draft RPSLng December 2002 1. Introduction RFC 2622 [1] defines the RPSL language for the IPv4 unicast routing protocols and a series of guidelines for extending the language itself. This document proposes to extend RPSL according to the following goals and requirements: provide RPSL extensibility in the dimension of address families. Specifically, to allow users to document routing policy for ipv6 and multicast. the extensions must be backwards compatible and minimise risk of breaking existing tools. For instance, introducing a new class or attribute will less probably break the tools than would changing the format of an existing attribute. Section 10 of RFC2622 provides guidelines. clarity and non-ambiguity: RPSL information is used by software tools and by humans. minimise duplication of information, particularly when routing policies for different address families are the same. Internet Routing Registry (IRR) system requirements: It is impossible to consider RPSL extensions as a pure language modification. The capabilities and established operational practices the users are familiar with when interacting with the servers supporting IRR must also be taken into account. An important point is to note the fact that there are two address families, corresponding to the two versions of the IP protocol currently in use in the Internet, but there are at least four distinct routing policies that need to be described (IPv4 {unicast|multicast}, IPv6 {unicast|multicast}). Damas, et al. Expires June 18, 2003 [Page 2] Internet-Draft RPSLng December 2002 2. Specifying routing policy for different address families Routing policy is currently specified in the aut-num class using "import:"and "export:" attributes. Sometimes it is important to distinguish policy for different address families, as well as a unicast routing policy from a multicast one. Use of existing import and export attributes is not a good option since itbreaks backward compatibility and could undermine clarity in the expressions. Keeping this in mind, the "import:" and "export:" attributes implicitly specifyipv4 unicast policy and remain as defined previously in RPSL and new multi-protocol (mp) attributes are introduced. These will be described below. 2.1 The afi dictionary attribute In this section we introduce a new dictionary attribute: Address family, , is an RPSL list of address families for which the policy expression should be evaluated. is mandatory within the new mp attributes introduced in this document. The possible values for are: ipv4 ipv4.unicast (equivalent to ipv4) ipv4.multicast ipv6 ipv6.unicast (equivalent to ipv6) ipv6.multicast Appearance of these values in an attribute's value must be preceded by the keyword afi. An is defined as a comma separated list of one or more afi values. 2.2 mp-import and mp-export Three new policy attributes are introduced: mp-import: mp-export: mp-default: These attributes incorporate the afi (address-family) specification. Damas, et al. Expires June 18, 2003 [Page 3] Internet-Draft RPSLng December 2002 The definition of the "mp-import:" attribute is as follows: mp-import ::= [protocol ] [into ] ::= afi accept | afi accept except | afi accept refine ::= [ ... ] ::= from [action ]; The specification indicates the AS (and the router if present) ::= [] [at ] | with and being expressions over router IPv4 or IPv6 addresses (specifying their address family with the use of the appropriate "afi " term), inet-rtr names, and rtr-set names using operators AND, OR, and EXCEPT. In the same manner the expression is the extension of the RPSL expression [section 5.4 of RFC2622], requiring the presence of an "afi " term before each address or address-prefix set. The address family may be specified at any level of nesting of Damas, et al. Expires June 18, 2003 [Page 4] Internet-Draft RPSLng December 2002 , and is valid only within the that contains it. Therefore in the example aut-num: AS65534 mp-import: afi ipv6.unicast,ipv4 from AS1 action pref = 1; accept as-foo except { afi ipv6.unicast,ipv4 from AS2 action pref = 2; accept AS226 except { afi ipv6.unicast from AS3 action pref = 3; accept {3FFE:FFFF::/35} } } the last (rightmost) "except" is evaluated only for the ipv6 unicast address family, while other import-expressions are evaluated for both the ipv6 and ipv4 unicast address families. The evaluation of an is done by evaluating all of its components. Evaluation of peering-sets and filter-sets is constrained by the address family. Such constraints may result in a {NOT ANY} or invalid depending on implicit or explicit definitions of the address family in the set. In the latter case an error is returned. {NOT ANY} filter may issue a warning. Conflicts with explicit or implicit declarations are resolved at runtime, that is during evaluation of a policy expression. For example, when evaluating the following import policy: aut-num: AS2 mp-import: afi ipv6 from AS1 accept {193.0.0.0/22} the filter should be evaluated as {NOT ANY}. aut-num: AS2 mp-import: afi ipv6.unicast { from AS-ANY action med = 0; accept {3FFE:FFFF::/35}; } refine { afi ipv6.unicast from AS1 at 3FFE:FFFF::1 action pref = 1; accept AS-UPSTREAM; from prng6-ebgp-peers action pref = 2; accept AS1; } In this example only ipv6 prefixes originated by AS1 will be collected, and while evaluating AS-UPSTREAM, an as-set, only ipv6 prefixes of the member ASes will be considered. Export policy is specified in the mp-export attribute. The mp-export attribute is defined in a symmetric way to the mp-import attribute. Damas, et al. Expires June 18, 2003 [Page 5] Internet-Draft RPSLng December 2002 The "mp-default:" attribute is defined as mp-default: [action ] [networks ] using the definitions above for and 2.3 Additional values for Two new additional values are possible for specification: BGP4+ MBGP both support the same options available for the BGP4 value. Damas, et al. Expires June 18, 2003 [Page 6] Internet-Draft RPSLng December 2002 3. New classes and attributes to support the extensions 3.1 as-set Class The as-set class defines a set of Autonomous Systems (AS), specified either directly by listing them in the members attribute, or indirectly by referring to another as-sets or using the mbrs-by-ref facility. More importantly, "In a context that expects a route set (e.g. members attribute of the route-set class), [...] an as-set AS-X defines the set of routes that are originated by the ASes in AS-X.", [section 5.3 of RFC2622]. The as-set class is therefore used to collect a set of route prefixes, which may be restricted to a specific address family. The existing as-set class does not need any modifications. The evaluation of the class must be filtered to obtain prefixes belonging to a particular address family using the traditional filtering mechanism in use in IRR systems today. 3.2 route6 Class An ipv6 inter-AS route has specific properties, such as prefix format, storage requirements that are different from the existing route class. Additionally, IRR systems use filters to select which type of information is returned to the requester. These filters are designed to operate by receiving a class type as operand. In the case of route objects, the attribute which is the class's primary key is where the route itself is defined. It is therefore preferable to create a new route6 class than a multi-protocol class. Each inter-AS ipv6 route originated by an AS is thus specified as: route6: [mandatory] [single] [primary/look-up key] ... (rest an in the route class) route6: 2001:610:240::/48 origin: AS3333 ... 3.3 route-set This class is used in expressions to specify a set of route prefixes. Damas, et al. Expires June 18, 2003 [Page 7] Internet-Draft RPSLng December 2002 A new attribute "mp-members:" is defined for this class with the following syntax: mp-members: afi list of or afi or afi route-set: rs-foo mp-members: afi ipv6 rs-bar # common members with afi constraint mp-members: afi ipv6 rs-foo2, 3FFE:FFFF::/35 # v6 only members... mp-members: afi ipv4 rs-foo3, 128.9.0.0/16 3.4 filter-set The new "mp-filter:" attribute defines the set's policy filter. A policy filter is a logical expression which when applied to a set of routes returns a subset of these routes. mp-filter: afi is defined in section Section 2.2. The relevant parts of the new filter-set class are shown below: filter-set: [mandatory] [ single] [class key] mp-filter: [optional] [multiple] filter: [optional] [multiple] ... Note that according to this definition empty filters are possible and should be handled correctly. 3.5 peering-set An "mp-peering:" attribute is introduced in this class. mp-peering: afi Section 2.2 Damas, et al. Expires June 18, 2003 [Page 8] Internet-Draft RPSLng December 2002 peering-set: [mandatory] [single] [class key] peering: [optional] [multiple] mp-peering: [optional] [multiple] ... Example: peering-set: prng-ebgp-peers mp-peering: afi ipv6 AS2 3FFE:FFFF::1 at 3FFE:FFFF::2 3.6 inet-rtr Class This class gets two new attributes: "interface:" which allows the definition of generic interfaces, including the information previously contained in the "ifaddr:" attribute and new types such as tunnels. mp-peer which includes and extends the functionality of the exisiting "peer:" attribute. interface: afi
masklen [ tunnel , ] The new syntax allows native IPv4 and IPv6 interface definitions as well as the definition of tunnels as virtual interfaces. Without the optional part, this attribute allows the same functionality as the "ifaddr:" attribute but extends it to allow IPv6 addresses. In the case of the interface being a tunnel, the optional part describes the tunnel configuration as follows: remote-endpoint-address indicates the IP address of the remote endpoint of the tunnel. The address family must match that of the local endpoint. denotes the encapsulation used in the tunnel and is one of {GRE,IPv6inIPv4,IPinIP,DVMRP} Routing policies for these routers should be described in the appropriate classes (eg. peering and autnum). Damas, et al. Expires June 18, 2003 [Page 9] Internet-Draft RPSLng December 2002 mp-peer: afi
| | | 3.7 rtr-set Class mp-members: list of | | afi list of mp-members: [optional] [multiple] Damas, et al. Expires June 18, 2003 [Page 10] Internet-Draft RPSLng December 2002 4. Security Considerations This document describes extensions to RPSL, a language for expressing routing policies. The extensions introduce ways of making the configurations currently available for describing IPv4 routing policies to IPv6. They introduce no additional security mechanisms or threats. Damas, et al. Expires June 18, 2003 [Page 11] Internet-Draft RPSLng December 2002 5. Acknowldegments The authors wish to thank all the people who have contributed to this document through numerous discussions. Particularly Ekaterina Petrusha for highly valuable discussions and suggestions. Shane Kerr, Engin Gunduz, Mark Blanchet and David Kessens participated constructively in many discussions. Finally Cengiz Alaettinoglu who is still the reference in all things RPSL. Damas, et al. Expires June 18, 2003 [Page 12] Internet-Draft RPSLng December 2002 References [1] Alaettinoglu, C., Villamizar, C., Gerich, E., Kessens, D., Meyer, D., Bates, T., Karrenberg, D. and M. Terpstra, "Routing Policy Specification Language (RPSL)", RFC 2622, June 1999. Authors' Addresses Joao Damas EMail: joao@psg.com Florent Parent Viagenie EMail: Florent.Parent@viagenie.qc.ca Andrei Robachevksi RIPE NCC EMail: andrei@ripe.net Damas, et al. Expires June 18, 2003 [Page 13] Internet-Draft RPSLng December 2002 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Full Copyright Statement Copyright (C) The Internet Society (2002). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assignees. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION Damas, et al. Expires June 18, 2003 [Page 14] Internet-Draft RPSLng December 2002 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Damas, et al. Expires June 18, 2003 [Page 15]